W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes
W3C XML Schema Definition Language (XSD) 1.1 Part 2: Datatypes
W3C Recommendation 5 April 2012
This version:
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Editors (Version 1.1):
David Peterson, invited expert (SGML
Works!
Shudi (Sandy) Gao 高殊镝, IBM
Ashok Malhotra, Oracle Corporation
C. M. Sperberg-McQueen, Black Mesa Technologies LLC
Henry S. Thompson, University of Edinburgh
Editors (Version 1.0):
Paul V. Biron, Kaiser Permanente, for Health Level Seven
Ashok Malhotra, Oracle Corporation
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Abstract
XML Schema: Datatypes
is part 2 of the specification of
the XML Schema language. It defines facilities for defining datatypes
to be used in XML Schemas as well as other XML specifications. The
datatype language, which is itself represented in XML, provides a superset of the
capabilities found in XML
document type definitions (DTDs) for specifying datatypes on elements
and attributes.
Status of this Document
This section describes the status of this document at the
time of its publication. Other documents may supersede this
document. A list of current W3C publications and the latest
revision of this technical report can be found in the
W3C technical reports index
at
This
W3C Recommendation
specifies
the W3C XML Schema Definition Language (XSD) 1.1 Part 2:
Datatypes.
It
is here made available for review by
W3C members and the public.
Changes since the previous public Working Draft include the following:
Some minor errors, typographic and otherwise,
have been corrected.
For those primarily interested in the changes since version 1.0,
the appendix
Changes since version 1.0 (§I)
is the recommended starting
point. An accompanying version of this document displays in color
all changes to normative text since version 1.0; another shows
changes since the previous Working Draft.
Comments on this document should be made in W3C's public
installation of Bugzilla, specifying "XML Schema" as the product.
Instructions can be found at
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the comment. Each Bugzilla entry and email message should contain
only one comment.
This document has been reviewed by W3C
Members, by software developers, and by other W3C groups and
interested parties, and is endorsed by the Director as a W3C
Recommendation. It is a stable document and may be used as
reference material or cited from another document. W3C's role in
making the Recommendation is to draw attention to the specification
and to promote its widespread deployment. This enhances the
functionality and interoperability of the Web.
An
implementation report
for XSD
1.1 was prepared and used in the
Director's decision to publish the previous version of this specification
as a Proposed Recommendation. The Director's decision to publish
this document as a W3C Recommendation is based on consideration
of reviews of the Proposed Recommendation by the public and by
the members of the W3C Advisory committee.
The W3C XML Schema Working Group intends to process comments
made about this recommendation, with any approved changes being
handled as errata to be published separately.
This document has been produced by the
W3C XML Schema Working
Group
as part of the W3C
XML Activity
. The
goals of the XML Schema language version 1.1 are discussed in the
Requirements
for XML Schema 1.1
document. The authors of this document
are the members of the XML Schema Working Group. Different parts
of this specification have different editors.
This document was produced by a group operating under the
February 2004 W3C Patent Policy
. W3C maintains a
public
list of any patent disclosures
made in connection with the
deliverables of the group; that page also includes instructions
for disclosing a patent. An individual who has actual knowledge
of a patent which the individual believes contains
Essential
Claim(s)
must disclose the information in
accordance with
section
6 of the W3C Patent Policy
The English version of this specification is the only normative
version. Information about translations of this document is
available at
Table of Contents
Introduction
1.1
Introduction to Version 1.1
1.2
Purpose
1.3
Dependencies on Other Specifications
1.4
Requirements
1.5
Scope
1.6
Terminology
1.7
Constraints and Contributions
Datatype System
2.1
Datatype
2.2
Value space
Identity
Equality
Order
2.3
The Lexical Space and Lexical Mapping
Canonical Mapping
2.4
Datatype
Distinctions
Atomic vs. List vs. Union Datatypes
Special vs. Primitive vs.
Ordinary
Datatypes
Definition, Derivation, Restriction, and Construction
Built-in vs. User-Defined Datatypes
Built-in Datatypes and Their Definitions
3.1
Namespace considerations
3.2
Special Built-in Datatypes
anySimpleType
anyAtomicType
3.3
Primitive Datatypes
string
boolean
decimal
float
double
duration
dateTime
time
date
gYearMonth
gYear
gMonthDay
gDay
gMonth
hexBinary
base64Binary
anyURI
QName
NOTATION
3.4
Other Built-in Datatypes
normalizedString
token
language
NMTOKEN
NMTOKENS
Name
NCName
ID
IDREF
IDREFS
ENTITY
ENTITIES
integer
nonPositiveInteger
negativeInteger
long
int
short
byte
nonNegativeInteger
unsignedLong
unsignedInt
unsignedShort
unsignedByte
positiveInteger
yearMonthDuration
dayTimeDuration
dateTimeStamp
Datatype components
4.1
Simple Type Definition
The Simple Type Definition Schema Component
XML Representation of Simple Type Definition Schema Components
Constraints on XML Representation of Simple Type Definition
Simple Type Definition Validation Rules
Constraints on Simple Type Definition Schema Components
Built-in Simple Type Definitions
4.2
Fundamental Facets
ordered
bounded
cardinality
numeric
4.3
Constraining Facets
length
minLength
maxLength
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minExclusive
minInclusive
totalDigits
fractionDigits
Assertions
explicitTimezone
Conformance
5.1
Host Languages
5.2
Independent implementations
5.3
Conformance of data
5.4
Partial Implementation of Infinite Datatypes
Appendices
Schema for Schema Documents (Datatypes)
(normative)
DTD for Datatype Definitions (non-normative)
Illustrative XML representations for the built-in simple type definitions
C.1
Illustrative XML representations for the built-in primitive type definitions
C.2
Illustrative XML representations for the built-in ordinary type definitions
Built-up Value Spaces
D.1
Numerical Values
Exact Lexical Mappings
D.2
Date/time Values
The Seven-property Model
Lexical Mappings
Function
Definitions
E.1
Generic Number-related Functions
E.2
Duration-related Definitions
E.3
Date/time-related Definitions
Normalization of property values
Auxiliary Functions
Adding durations to dateTimes
Time on timeline
Lexical mappings
Canonical Mappings
E.4
Lexical and Canonical Mappings for Other Datatypes
Lexical and canonical mappings for
Datatypes and Facets
F.1
Fundamental Facets
Regular Expressions
G.1
Regular expressions and branches
G.2
Pieces, atoms, quantifiers
G.3
Characters and metacharacters
G.4
Character Classes
Character class expressions
Character Class Escapes
Implementation-defined and implementation-dependent features (normative)
H.1
Implementation-defined features
H.2
Implementation-dependent features
Changes since version 1.0
I.1
Datatypes and Facets
I.2
Numerical Datatypes
I.3
Date/time Datatypes
I.4
Other changes
Glossary (non-normative)
References
K.1
Normative
K.2
Non-normative
Acknowledgements (non-normative)
1 Introduction
1.1 Introduction to Version 1.1
The Working Group has two main goals for this version of W3C XML
Schema:
Significant improvements in simplicity of design and clarity
of exposition
without
loss of backward
or
forward compatibility;
Provision of support for versioning of XML languages defined
using the XML Schema specification, including the XML transfer syntax
for schemas itself.
These goals are slightly in tension with one another -- the
following summarizes the Working Group's strategic guidelines for
changes between versions 1.0 and 1.1:
Add support for versioning (acknowledging that this
may
be slightly disruptive to the XML transfer syntax at
the margins)
Allow bug fixes (unless in specific cases we decide that the
fix is too disruptive for a point release)
Allow editorial changes
Allow design cleanup to change behavior in edge
cases
Allow relatively non-disruptive changes to type hierarchy (to
better support current and forthcoming international standards and W3C
recommendations)
Allow design cleanup to change component structure (changes
to functionality restricted to edge cases)
Do not allow any significant changes in functionality
Do not allow any changes to XML transfer syntax except those
required by version control hooks and bug fixes
The overall aim as regards compatibility is that
All schema documents conformant to version 1.0 of this
specification should also conform to version 1.1, and should have the
same validation behavior across 1.0 and 1.1 implementations (except
possibly in edge cases and in the details of the resulting
PSVI);
The vast majority of schema documents conformant to version
1.1 of this specification should also conform to version 1.0, leaving
aside any incompatibilities arising from support for versioning, and
when they are conformant to version 1.0 (or are made conformant by the
removal of versioning information), should have the same validation
behavior across 1.0 and 1.1 implementations (again except possibly in
edge cases and in the details of the resulting PSVI);
1.2 Purpose
The
[XML]
specification defines limited
facilities for applying datatypes to document content in that documents
may contain or refer to DTDs that assign types to elements and attributes.
However, document authors, including authors of traditional
documents
and those transporting
data
in XML,
often require a higher degree of type checking to ensure robustness in
document understanding and data interchange.
The table below offers two typical examples of XML instances
in which datatypes are implicit: the instance on the left
represents a billing invoice, the instance on the
right a memo or perhaps an email message in XML.
Data oriented
Document oriented
We need to discuss the latest
draft
Either email me at
mailto:paul.v.biron@kp.org
or call
The invoice contains several dates and telephone numbers, the postal
abbreviation for a state (which comes from an enumerated list of
sanctioned values), and a ZIP code (which takes a definable regular
form). The memo contains many of the same types of information:
a date, telephone number, email address and an "importance" value
(from an enumerated list, such as "low", "medium" or "high").
Applications which process invoices and memos need to raise exceptions
if something that was supposed to be a date or telephone number does
not conform to the rules for valid dates or telephone numbers.
In both cases, validity constraints exist on the content of the
instances that are not expressible in XML DTDs. The limited
datatyping facilities in XML have prevented validating XML processors
from supplying the rigorous type checking required in these
situations. The result has been that individual applications
writers have had to implement type checking in an ad hoc manner.
This specification addresses the need of both document authors and
applications writers for a robust, extensible datatype system for XML
which could be incorporated into XML processors. As discussed
below, these datatypes could be used in other XML-related standards as
well.
1.3 Dependencies on Other Specifications
Other specifications on which this one depends
are listed in
References (§K)
This specification defines some datatypes which depend on
definitions in
[XML]
and
[Namespaces in XML]
; those
definitions, and therefore the datatypes based on them, vary between
version 1.0 (
[XML 1.0]
[Namespaces in XML 1.0]
) and version 1.1 (
[XML]
[Namespaces in XML]
) of those specifications. In any given use
of this specification, the choice of the 1.0 or the 1.1 definition of
those datatypes is
implementation-defined
Conforming implementations of this specification
may provide either
the 1.1-based datatypes or the 1.0-based datatypes, or both. If both
are supported, the choice of which datatypes to use in a particular
assessment episode
should
be under user control.
Note:
When this specification is used to check the datatype validity of XML
input, implementations
may
provide the heuristic of using the 1.1
datatypes if the input is labeled as XML 1.1, and using the 1.0 datatypes if
the input is labeled 1.0, but this heuristic
should
be subject to
override by users, to support cases where users wish to accept XML 1.1
input but validate it using the 1.0 datatypes, or accept XML 1.0 input
and validate it using the 1.1 datatypes.
This specification
makes use of the EBNF notation used in the
[XML]
specification. Note
that some constructs of the EBNF notation used here
resemble the regular-expression syntax defined in this specification
Regular Expressions (§G)
), but that they are not
identical: there are differences.
For a fuller description of the EBNF notation, see
Section
6. Notation
of the
[XML]
specification.
1.4 Requirements
The
[XML Schema Requirements]
document spells out
concrete requirements to be fulfilled by this specification,
which state that the XML Schema Language must:
provide for primitive data typing, including byte, date,
integer, sequence, SQL and Java primitive datatypes, etc.;
define a type system that is adequate for import/export
from database systems (e.g., relational, object, OLAP);
distinguish requirements relating to lexical data representation
vs.
those governing an underlying information set;
allow creation of user-defined datatypes, such as
datatypes that are derived from existing datatypes and which
may constrain certain of its properties (e.g., range,
precision, length, format).
1.5 Scope
This specification
defines datatypes that can be used in an XML Schema.
These datatypes can be specified for element content that would be
specified as
#PCDATA
and attribute values of
various types
in a
DTD. It is the intention of this specification that it be usable
outside of the context of XML Schemas for a wide range of other
XML-related activities such as
[XSL]
and
[RDF Schema]
1.6 Terminology
The terminology used to describe XML Schema Datatypes is defined in
the body of this specification. The terms defined in the following
list are used in building those definitions and in describing the
actions of a datatype processor:
[Definition:]
for compatibility
A feature of this specification included solely to ensure that
schemas which use this feature remain compatible with
[XML]
[Definition:]
match
(Of strings or names:)
Two strings or names being compared must be
identical. Characters with multiple possible representations in
ISO/IEC 10646 (e.g. characters with both precomposed and
base+diacritic forms) match only if they have the same representation
in both strings. No case folding is performed.
(Of strings and rules
in the grammar:)
A string matches a grammatical production
if and only if it belongs to the language
generated by that production.
[Definition:]
may
Schemas,
schema documents, and processors
are permitted to but need
not behave as described.
[Definition:]
should
It is recommended that schemas, schema documents, and
processors behave as described, but there
can be valid reasons for them not to; it is important that the
full implications be understood and carefully weighed before
adopting behavior at variance with the recommendation.
[Definition:]
must
(Of schemas and
schema documents:)
Schemas and documents
are required to behave as described; otherwise they are in
error
(Of processors:)
Processors are required to behave as described.
[Definition:]
must not
Schemas, schema documents
and processors are forbidden to behave as
described; schemas and documents which nevertheless
do so are in
error
[Definition:]
error
A failure of a
schema or schema
document
to conform to the rules of this specification.
Except as otherwise specified,
processors
must
distinguish
error-free (conforming) schemas and schema documents
from those with errors;
if a schema
used in type-validation or a schema document
used in constructing a schema
is in error, processors
must
report the fact;
if more than one is in error, it is
implementation-dependent
whether more than one is reported as being in error.
If more than one of the constraints given in
this specification is violated, it
is
implementation-dependent
how many of the violations, and which, are
reported.
Note:
Failure of an XML element or attribute to be
datatype-valid against a particular
datatype in a particular schema is not in itself a failure
to conform to this specification and thus,
for purposes of this specification, not an error.
[Definition:]
user option
A choice left under the control of the user of a processor,
rather than being fixed for all users or uses of the processor.
Statements in this specification that "Processors
may
at user option" behave in a certain way mean that
processors
may
provide mechanisms to allow users
(i.e. invokers of the processor) to enable or disable the
behavior indicated. Processors which do not provide such
user-operable controls
must not
behave in the way indicated.
Processors which do provide such
user-operable controls
must
make it possible for the user
to disable the optional behavior.
Note:
The normal expectation is that the default setting for
such options will be to disable the
optional
behavior in question,
enabling it only when the user explicitly requests it. This
is not, however, a requirement of conformance: if the
processor's documentation makes clear that the user can
disable the optional
behavior, then invoking the processor without
requesting that it be disabled can be taken as equivalent to
a request that it be enabled.
It is required,
however, that it in fact be possible for the user to disable the
optional behavior.
Note:
Nothing in this specification constrains the manner
in which processors allow users to control user options.
Command-line options, menu choices in a graphical user
interface, environment variables, alternative call patterns
in an application programming interface, and other
mechanisms may all be taken as providing user options.
1.7 Constraints and Contributions
This specification provides three different kinds of normative
statements about schema components, their representations in XML and
their contribution to the schema-validation of information items:
[Definition:]
Constraint on Schemas
Constraints on the schema components themselves, i.e. conditions
components
must
satisfy to be components at all.
Largely to be found in
Datatype components (§4)
[Definition:]
Schema Representation Constraint
Constraints on the representation of schema components in XML.
Some but not all of these are expressed in
Schema for Schema Documents (Datatypes)
(normative) (§A)
and
DTD for Datatype Definitions (non-normative) (§B)
[Definition:]
Validation Rule
Constraints expressed by schema components which information items
must
satisfy to be schema-valid. Largely to
be found in
Datatype components (§4)
2 Datatype System
This section describes the conceptual framework behind the datatype system defined in this
specification. The framework has been influenced by the
[ISO 11404]
standard on language-independent datatypes as
well as the datatypes for
[SQL]
and for programming
languages such as Java.
The datatypes discussed in this specification are for the most part well known abstract
concepts such as
integer
and
date
. It is not
the place of this specification to thoroughly define these abstract concepts; many
other publications provide excellent definitions. However, this specification will attempt to describe the
abstract concepts well enough that they can be readily recognized and
distinguished from other abstractions with which they may be
confused.
Note:
Only those operations and relations needed for schema processing
are defined in this specification. Applications using these datatypes
are generally expected to implement appropriate additional functions
and/or relations to make the datatype generally useful. For
example, the description herein of the
float
datatype
does not define addition or multiplication, much less all of the
operations defined for that datatype in
[IEEE 754-2008]
on
which it is based.
For some datatypes (e.g.
language
or
anyURI
) defined in part by
reference to other specifications which impose constraints not part of
the datatypes as defined here, applications may also wish to check
that values conform to the requirements given in the current version
of the relevant external specification.
2.1 Datatype
[Definition:]
In
this specification, a
datatype
has
three properties:
value space
, which is a set of
values.
lexical space
, which is a set of
literals
used to denote the values.
A small collection of
functions, relations, and
procedures
associated with the datatype. Included are
equality and (for some datatypes)
order relations on the
value space
, and a
lexical mapping
, which is a mapping from the
lexical space
into
the
value space
Note:
This specification only defines the operations and relations needed
for schema processing. The choice of terminology for
describing/naming the datatypes is selected to guide users and
implementers in how to expand the datatype to be generally
useful—i.e., how to recognize the "real world"
datatypes and their variants for which the datatypes defined herein
are meant to be used for data interchange.
Along with the
lexical mapping
it is
often useful to have an inverse which provides a standard
lexical representation
for each value. Such
canonical mapping
is not required for
schema processing, but is described herein for the benefit of users of
this specification, and other specifications which might find it
useful to reference these descriptions normatively.
For some datatypes, notably
QName
and
NOTATION
, the mapping from
lexical representations to values is context-dependent; for these
types, no
canonical mapping
is defined.
Note:
Where
canonical mappings
are defined in this specification, they are
defined for
primitive
datatypes. When a datatype is derived using facets which directly
constrain the
value space
, then for each value eliminated from the
value space
, the corresponding lexical representations are dropped
from the lexical space. The
canonical mapping
for such a datatype is
a subset of the
canonical mapping
for its
primitive
type and
provides a
canonical representation
for each value remaining in the
value space
The
pattern
facet, on the other hand, and
any other (
implementation-defined
lexical
facets,
restrict
the
lexical space
directly. When more than one lexical
representation is provided for a given value,
such facets
may
remove the
canonical representation
while
permitting a different lexical representation; in this case, the value
remains in the
value space
but has no
canonical representation
This specification provides no recourse in such situations.
Applications are free to deal with it as they see fit.
Note:
This specification sometimes uses the shorter form "type"
where one might strictly speaking expect the longer form
"datatype" (e.g. in the phrases
"union type", "list type",
"base type", "item type", etc.
No systematic distinction is intended between
the forms of these phrase with "type" and
those with "datatype";
the two forms are used interchangeably.
The distinction between "datatype"
and "simple type definition", by contrast,
carries more information: the datatype is characterized by its
value space
lexical space
lexical mapping
, etc., as
just described, independently of the specific facets or
other definitional mechanisms used in the simple type
definition to describe that particular
value space
or
lexical space
. Different simple type definitions
with different selections of facets can describe the
same datatype.
2.2 Value space
2.2.1
Identity
2.2.2
Equality
2.2.3
Order
[Definition:]
The
value space
of a
datatype
is the set of values for that
datatype.
Associated with each value space are
selected operations and relations necessary to permit proper schema
processing. Each value in the value space of a
primitive
or
ordinary
datatype is
denoted by one or more character strings in its
lexical space
according to
the lexical
mapping
special
datatypes, by contrast, may include "ineffable"
values not mapped to by any lexical representation.
(If the mapping is restricted during a
derivation in such a way that a value has no denotation, that value is
dropped from the value space.)
The value spaces of datatypes are abstractions,
and are defined in
Built-in Datatypes and Their Definitions (§3)
to the extent needed to clarify them for readers. For example,
in defining the numerical datatypes, we assume some general numerical
concepts such as number and integer are known. In many cases we
provide references to other documents providing more complete
definitions.
Note:
The value spaces and the values therein are
abstractions.
This specification does not prescribe any
particular internal representations that must be used when
implementing these datatypes. In some cases, there are
references to other specifications which do prescribe specific
internal representations; these specific internal representations must
be used to comply with those other specifications, but need not be
used to comply with this specification.
In addition, other applications are expected to define additional
appropriate operations and/or relations on these value spaces (e.g.,
addition and multiplication on the various numerical datatypes'
value spaces), and are permitted where appropriate to even redefine
the operations and relations defined within this specification,
provided that
for schema processing the relations and operations
used are those defined herein
The
value space
of a datatype can
be defined in one of the following ways:
defined elsewhere
axiomatically from fundamental notions (intensional definition) [see
primitive
enumerated outright from values
of an already defined datatype (extensional definition) [see
enumeration
defined by restricting the
value space
of an already
defined datatype to a particular subset with a given set of properties
[see
derived
defined as a combination of values from one or more already
defined
value space
(s) by a specific construction procedure [see
list
and
union
The relations of
identity
and
equality
are required for each
value space. An
order relation is specified for some value spaces, but not
all.
A very few datatypes have other relations or
operations prescribed for the purposes of this specification.
2.2.1 Identity
The identity relation is always defined. Every value space
inherently has an identity relation. Two things are
identical
if and only
if they are actually the same thing: i.e., if there is no way
whatever to tell them apart.
Note:
This does not preclude implementing datatypes by using more than
one
internal
representation for a given value, provided
no mechanism inherent in the datatype implementation (i.e., other than
bit-string-preserving "casting" of the datum to a different
datatype) will distinguish between the two representations.
In the identity relation defined herein, values from different
primitive
datatypes'
value spaces
are made artificially
distinct if they might otherwise be considered identical. For
example, there is a number
two
in the
decimal
datatype and a number
two
in the
float
datatype. In the identity relation defined herein,
these two values are considered distinct. Other applications
making use of these datatypes may choose to consider values such as
these identical, but for the view of
primitive
datatypes'
value spaces
used herein, they are distinct.
WARNING:
Care must be taken when identifying
values across distinct primitive datatypes. The
literals
0.1
' and '
0.10000000009
' map
to the same value in
float
(neither 0.1 nor 0.10000000009 is in the value space, and
each literal is mapped to the
nearest value, namely 0.100000001490116119384765625), but map to
distinct values in
decimal
Note:
Datatypes
constructed
by
facet-based restriction
do not create new
values; they define subsets of some
primitive
datatype's
value space
. A consequence of this fact is that the
literals
+2
', treated as a
decimal
+2
', treated as an
integer
, and
+2
', treated as a
byte
, all denote the
same value. They are not only equal but identical.
Given a list
and a list
and
are the same list if they are the same sequence of atomic values.
The necessary and sufficient conditions for this identity are
that
and
have the same length and that the items of
are pairwise identical to the items of
Note:
It is a consequence of the rule just given for list identity
that there is only one empty list. An empty list declared as
having
item type
decimal
and an empty
list declared as having
item type
string
are not only equal but identical.
2.2.2 Equality
Each
primitive
datatype has prescribed an equality relation for
its value space. The equality relation for most datatypes is the
identity relation. In the few cases where it is not,
equality
has been carefully defined so that for
most operations of
interest to the datatype, if
two values are equal and one is substituted for the other as an
argument to any of the operations, the results will always also be
equal.
On the other hand, equality need not cover the entire value space
of the datatype (though it usually does). In
particular, NaN
is not equal to itself in the
float
and
double
datatypes.
This
equality relation is used in
conjunction with identity when
making
facet-based restrictions
by
enumeration
when checking identity constraints (in the context of
[XSD 1.1 Part 1: Structures]
and when checking value
constraints. It is used in
conjunction with order when making
facet-based restrictions
involving order. The
equality relation used in the evaluation of XPath expressions
may differ. When
processing
XPath expressions
as part of XML schema-validity
assessment
or
otherwise testing membership in the
value space
of a datatype whose derivation involves
assertions
equality (like all other relations) within those expressions is interpreted
using the rules of XPath (
[XPath 2.0]
).
All comparisons for
"sameness" prescribed by this specification
test for either
equality or identity,
not for identity alone.
Note:
In the prior version of this specification (1.0), equality was
always identity. This has been changed to permit the datatypes
defined herein to more closely match the "real world"
datatypes for which they are intended to be used as transmission
formats.
For example, the
float
datatype has an equality
which is not the identity ( −0 = +0 , but
they are not identical—although they
were
identical
in the 1.0 version of this specification), and whose domain excludes
one value, NaN, so that NaN ≠ NaN .
For another example, the
dateTime
datatype
previously lost any time-zone offset information in the
lexical representation
as the value was converted to
UTC
now the time zone offset
is retained and two values representing the same "moment in
time" but with different remembered time zone offsets are now
equal
but not
identical
In the equality relation defined herein, values from different
primitive data spaces are made artificially unequal even if they might
otherwise be considered equal. For example, there is a number
two
in the
decimal
datatype and a number
two
in the
float
datatype. In the
equality relation defined herein, these two values are considered
unequal. Other applications making use of these datatypes may
choose to consider values such as these equal;
nonetheless, in the equality relation defined herein, they are unequal.
Two lists
and
are equal if and
only if they have the same length and their items are pairwise equal.
A list of length one containing a value
V1
and an atomic value
V2
are equal if and only if
V1
is equal to
V2
For the purposes of this specification, there is one equality
relation for all values of all datatypes (the union of the various
datatype's individual equalities, if one consider relations to be
sets of ordered pairs). The
equality
relation is
denoted by '=' and its negation by
'≠', each used as
a binary infix predicate:
and
. On the other
hand,
identity
relationships are always described in
words.
2.2.3 Order
For some
datatypes, an order relation is prescribed
for use in checking
upper and lower bounds of the
value space
. This order may be
partial
order, which means that there may be values in
the
value space
which are neither equal, less-than, nor
greater-than. Such value pairs are
incomparable
. In many cases,
no order
is prescribed; each pair of values is either
equal or
incomparable
[Definition:]
Two
values that are neither equal, less-than, nor greater-than are
incomparable
. Two values
that are not
incomparable
are
comparable
The order relation is used
in conjunction with equality when making
facet-based restrictions
involving order. This is the only use of
this
order relation for schema
processing. Of course, when
processing
XPath expressions
as part of XML schema-validity
assessment
or
otherwise testing membership in the
value space
of a datatype whose derivation involves
assertions
order (like all other relations) within those expressions is interpreted
using the rules of XPath (
[XPath 2.0]
).
In this specification, this less-than order relation is denoted by
'<' (and its inverse by '>'),
the weak order by '≤' (and its inverse by
'≥'), and the resulting
incomparable
relation by
'<>', each used as a binary infix predicate:
, and
<>
Note:
The weak order "less-than-or-equal" means
"less-than" or "equal"
and one
can tell which
. For example, the
duration
P1M (one month) is
not
less-than-or-equal P31D (thirty-one days) because P1M is not less than
P31D, nor is P1M equal to P31D. Instead, P1M is
incomparable
with P31D.) The formal
definition of order for
duration
duration (§3.3.6)
ensures
that this is true.
For
purposes of this specification, the value spaces of primitive datatypes are
disjoint, even in cases where the
abstractions they represent might be thought of as having
values in common. In the order
relations defined in this specification, values from
different value spaces are
incomparable
. For example, the numbers two
and three are values in both the
decimal
datatype and the float datatype. In the order relation defined
here,
the two in the decimal datatype
is
not less than the three in the float datatype;
the two values are
incomparable. Other
applications making use of these
datatypes may choose to consider values such as these comparable.
Note:
Comparison of values from different
primitive
datatypes
can sometimes be an error and sometimes not, depending on context.
When made for purposes of checking an enumeration constraint,
such a comparison is not in itself an error, but since
no
two values from different
primitive
value spaces
are
equal, any
comparison of
incomparable
values will invariably be false.
Specifying an upper or lower bound which is of the wrong primitive
datatype (and therefore
incomparable
with the values of the datatype
it is supposed to restrict) is, by contrast, always an error.
It is a consequence of the rules for
facet-based restriction
that in conforming simple type definitions, the
values of upper and lower bounds, and enumerated values,
must
be
drawn from the value space of the
base type
, which necessarily means
from the same
primitive
datatype.
Comparison of
incomparable
values in the context of an XPath
expression (e.g. in an assertion or in the rules for conditional type
assignment) can raise a dynamic error in the evaluation of the XPath
expression; see
[XQuery 1.0 and XPath 2.0 Functions and Operators]
for details.
2.3 The Lexical Space and Lexical Mapping
[Definition:]
The
lexical mapping
for a datatype is a prescribed
relation
which maps from the
lexical space
of the datatype
into its
value space
[Definition:]
The
lexical space
of a datatype is
the prescribed set of strings
which
the lexical
mapping
for that datatype
maps to values of that datatype.
[Definition:]
The members of the
lexical space
are
lexical representations
of the values to which they are
mapped.
Note:
For the
special
datatypes, the
lexical mappings
defined
here map from the
lexical space
into, but not onto, the
value space
The
value spaces
of the
special
datatypes
include "ineffable" values for which the
lexical mappings
defined
in this specification provide no lexical representation.
For the
primitive
and
ordinary
atomic datatypes, the
lexical mapping
is a
(total)
function on the entire
lexical space
onto
(not merely
into
) the
value space
: every member of the
lexical space
maps into the
value space
, and every value is mapped
to by some member of the
lexical space
For
union
datatypes, the
lexical mapping
is not necessarily a function, since the same
literal
may map to
different values in different member types. For
list
datatypes,
the
lexical mapping
is a function if and only if the
lexical mapping
of the list's
item type
is a function.
[Definition:]
A sequence of zero or more
characters in the Universal Character Set (UCS) which may or may not
prove upon inspection to be a member of the
lexical space
of a given
datatype and thus a
lexical representation
of a given value in that datatype's
value space
, is referred to as a
literal
The
term is used indifferently both for character sequences which are
members of a particular
lexical space
and for those which are
not.
If a derivation introduces a
pre-lexical
facet value (a new value for
whiteSpace
or an implementation-defined
pre-lexical
facet), the corresponding
pre-lexical
transformation of a character string,
if indeed it changed that string, could prevent that string from ever
having the
lexical mapping
of the derived datatype
applied to it. Character strings that a
pre-lexical
transformation blocks in this way
(i.e., they are not in the range of the
pre-lexical
facet's transformation) are always dropped from the derived datatype's
lexical space
Note:
One should be aware that in the context of XML
schema-validity
assessment
there are
pre-lexical
transformations of the
input character string
(controlled by the
whiteSpace
facet and any implementation-defined
pre-lexical
facets)
which result in the intended
literal
Systems other than
XML schema-validity
assessment
utilizing this specification may or may not implement these
transformations. If they do not, then input character strings
that would have been transformed into correct
lexical representations
when taken "raw", may not be
correct
lexical
representations
Should a derivation be made using a derivation mechanism that
removes
lexical representations
from the
lexical space
to the
extent that one or more values cease to have any
lexical representation
, then those values are dropped from the
value space
Note:
This could happen by means of a
pattern
or other
lexical
facet, or by a
pre-lexical
facet as described above.
Conversely, should a derivation remove values then their
lexical representations
are dropped from the
lexical space
unless
there is a facet value whose impact is defined to cause the
otherwise-dropped
lexical representation
to be mapped to another
value instead.
Note:
There are currently no facets with such an impact. There may
be in the future.
For example, '100' and '1.0E2' are two
different
lexical representations
from the
float
datatype which
both denote the same value. The datatype system defined in this
specification provides mechanisms for schema designers to control the
value space
and the corresponding set of acceptable
lexical representations
of those values for a datatype.
2.3.1 Canonical Mapping
While the datatypes defined in this specification often have a single
lexical representation
for
each value (i.e., each value in the datatype's
value space
is
denoted by a single
representation
in its
lexical space
), this is not always the case. The example in
the previous section shows two
lexical representations
from the
float
datatype which denote the same value.
[Definition:]
The
canonical mapping
is a prescribed subset of the inverse of a
lexical mapping
which is
one-to-one and whose domain (where possible) is the entire range of the
lexical mapping
(the
value space
).
Thus a
canonical mapping
selects one
lexical representation
for each
value in the
value space
[Definition:]
The
canonical
representation
of a value in the
value space
of a datatype is
the
lexical representation
associated with that value by the
datatype's
canonical mapping
Canonical
mappings
are not available for datatypes whose
lexical mappings
are context dependent (i.e., mappings for which the
value of a
lexical representation
depends on the context in which it
occurs, or for which a character string may or may not be a valid
lexical representation
similarly depending on its context)
Note:
Canonical
representations
are provided where feasible for the use of
other applications; they are not required for schema processing
itself.
A conforming schema processor implementation is
not required to implement
canonical
mappings
2.4 Datatype
Distinctions
2.4.1
Atomic vs. List vs. Union Datatypes
2.4.1.1
Atomic Datatypes
2.4.1.2
List Datatypes
2.4.1.3
Union datatypes
2.4.2
Special vs. Primitive vs.
Ordinary
Datatypes
2.4.2.1
Facet-based Restriction
2.4.2.2
Construction by List
2.4.2.3
Construction by Union
2.4.3
Definition, Derivation, Restriction, and Construction
2.4.4
Built-in vs. User-Defined Datatypes
It is useful to categorize the datatypes defined in this
specification along various dimensions, defining terms which
can be used to characterize datatypes and the
Simple Type Definition
which define them.
2.4.1 Atomic vs. List vs. Union Datatypes
First, we distinguish
atomic
list
, and
union
datatypes.
[Definition:]
An
atomic value
is an elementary value, not
constructed from simpler values by any user-accessible
means defined by this specification.
[Definition:]
Atomic
datatypes
are those whose
value spaces
contain only
atomic values
Atomic
datatypes are
anyAtomicType
and all
datatypes
derived
from it.
[Definition:]
List
datatypes are
those having values each of which consists of a finite-length
(possibly empty) sequence of
atomic values
. The values in a list are
drawn from some
atomic
datatype (or from
union
of
atomic
datatypes), which is
the
item type
of the
list
Note:
It is a consequence of constraints normatively specified elsewhere
in this document (in particular,
the component properties specified in
The Simple Type Definition Schema Component (§4.1.1)
that the
item type
of a list
may
be any
atomic
datatype, or any
union
datatype whose
basic members
are all
atomic
datatypes
(so a
list
of a
union
of
atomic
datatypes is possible, but not a
list
of a
union
of
lists
). The
item type
of a list
must not
itself be a list datatype.
[Definition:]
Union
datatypes
are (a) those whose
value spaces
lexical spaces
, and
lexical mappings
are the union of the
value spaces
lexical spaces
, and
lexical mappings
of one or more other datatypes, which are the
member types
of the
union, or (b) those derived by
facet-based restriction
of another union datatype.
Note:
It is a consequence of constraints normatively specified
elsewhere in this document (in particular,
the component properties specified in
The Simple Type Definition Schema Component (§4.1.1)
that any
primitive
or
ordinary
datatype
may
occur
among the
member types
of a
union
. (In particular,
union
datatypes may themselves be members of
unions
, as may
lists
.) The only prohibition is that no
special
datatype may be a member of a
union
For example, a single token which
matches
Nmtoken
from
[XML]
is in the value
space of the
atomic
datatype
NMTOKEN
, while a sequence of such tokens is in the value space of the
list
datatype
NMTOKENS
2.4.1.1 Atomic Datatypes
An
atomic
datatype has a
value space
consisting of a set of "atomic" or elementary values.
Note:
Atomic values are sometimes regarded, and described, as "not
decomposable", but in fact the values in several datatypes
defined here are described with internal structure, which is appealed
to in checking whether particular values satisfy various constraints
(e.g. upper and lower bounds on a datatype). Other specifications
which use the datatypes defined here may define operations which
attribute internal structure to values and expose or act upon that
structure.
The
lexical space
of an
atomic
datatype is a set of
literals
whose internal structure is specific to the datatype in
question.
There is one
special
atomic
datatype
anyAtomicType
), and a number of
primitive
atomic
datatypes which have
anyAtomicType
as their
base type
. All other
atomic
datatypes are
derived
either
from one of the
primitive
atomic
datatypes or from another
ordinary
atomic
datatype. No
user-defined
datatype
may
have
anyAtomicType
as its
base type
2.4.1.2 List Datatypes
List
datatypes are always
constructed
from some other type; they are never
primitive
. The
value space
of a
list
datatype is
the set of finite-length sequences of
zero or more
atomic
values
where each
atomic
value is drawn from the
value space
of the lists's
item type
and has a
lexical representation
containing no
whitespace.
The
lexical space
of a
list
datatype is a set of
literals
each
of which
is a space-separated sequence of
literals
of the
item type
[Definition:]
The
atomic
or
union
datatype that participates in the definition of a
list
datatype
is the
item type
of that
list
datatype.
If
the
item type
is a
union
, each of its
basic members
must
be
atomic
Example
list
datatype can be
constructed
from an ordinary
or
primitive
atomic
datatype whose
lexical space
allows
whitespace
(such as
string
or
anyURI
) or a
union
datatype any of whose
{member type definitions}
's
lexical space
allows space.
Since
list
items are separated at whitespace before the
lexical representations
of the items are mapped to values, no whitespace will ever occur
in the
lexical representation
of a
list
item, even when the item
type would in principle allow it.
For the same reason, when every possible
lexical representation
of a given
value in the
value space
of the
item type
includes whitespace,
that value can never occur as an item in any value of the
list
datatype.
Example
this is not list item 1
this is not list item 2
this is not list item 3
In the above example, the value of the
someElement
element
is not a
list
of
length
3;
rather, it is a
list
of
length
18.
When a datatype is
derived
by
restricting
list
datatype, the following
constraining facets
apply:
length
maxLength
minLength
enumeration
pattern
whiteSpace
assertions
For each of
length
maxLength
and
minLength
, the
length
is
measured in number
of list
items. The value of
whiteSpace
is fixed to the value
collapse
For
list
datatypes the
lexical space
is composed of space-separated
literals
of the
item type
Any
pattern
specified when a new datatype is
derived
from a
list
datatype
applies
to the members of the
list
datatype's
lexical space
, not to the members of the
lexical space
of the
item type
. Similarly,
enumerated
values are compared to the entire
list
, not to
individual list items,
and
assertions
apply to the entire
list
too.
Lists are identical if and only if they have the
same length and their items are pairwise identical; they are
equal if and only if they have the same length and their items
are pairwise equal. And
a list of length one whose item is an atomic value
V1
is
equal or identical
to an atomic value
V2
if and only if
V1
is
equal or identical
to
V2
Example
The
canonical mapping
of a
list
datatype maps each value onto the
space-separated concatenation of the
canonical
representations
of all the items in the value
(in order), using the
canonical mapping
of the
item type
2.4.1.3 Union datatypes
Union types
may be defined in either of two ways. When a union type is
constructed
by
union
, its
value space
lexical space
, and
lexical mapping
are the "ordered unions" of the
value spaces
lexical spaces
, and
lexical mappings
of its
member types
It will be observed that the
lexical mapping
of a union, so
defined, is not necessarily a function: a given
literal
may map to
one value or to several values of different
primitive
datatypes, and
it may be indeterminate which value is to be preferred in a particular
context. When the datatypes defined here are used in the context of
[XSD 1.1 Part 1: Structures]
, the
xsi:type
attribute defined by that
specification in section
xsi:type
can be used to indicate
which value a
literal
which is the content of an element should map
to. In other contexts, other rules (such as type coercion rules) may
be employed to determine which value is to be used.
When a union type is defined by
restricting
another
union
, its
value space
lexical space
and
lexical mapping
are subsets of the
value spaces
lexical spaces
, and
lexical mappings
of its
base type
Union
datatypes are always
constructed
from other
datatypes; they are never
primitive
. Currently,
there are no
built-in
union
datatypes.
Example
A prototypical example of a
union
type is the
maxOccurs attribute
on the
element element
in XML Schema itself: it is a union of nonNegativeInteger
and an enumeration with the single member, the string "unbounded", as shown below.
Any number (zero or more)
of ordinary
or
primitive
datatypes
can participate in a
union
type.
[Definition:]
The datatypes that participate in the
definition of a
union
datatype are known as the
member types
of that
union
datatype.
Note:
When datatypes are represented using XSD schema components, as
described in
Datatype components (§4)
, the member types of
a union are those simple type definitions given in the
{member type definitions}
property.
[Definition:]
The
transitive membership
of
union
is the set of its own
member types
, and the
member types
of its members, and so on. More formally, if
is a
union
, then (a) its
member types
are in the transitive membership
of
, and (b) for any datatypes
T1
and
T2
, if
T1
is in the transitive membership of
and
T2
is one of the
member types
of
T1
, then
T2
is also in the transitive membership
of
The
transitive membership
of a
union
must not
contain the
union
itself, nor
any datatype
derived
or
constructed
from the
union
[Definition:]
Those members of the
transitive membership
of a
union
datatype
which are themselves not
union
datatypes
are the
basic members
of
[Definition:]
If a datatype
is in the
transitive membership
of a
union
datatype
, but not one of
's
member types
then a sequence of one or more
union
datatypes necessarily exists,
such that the first is one of the
member types
of
, each
is one of the
member types
of its predecessor in the sequence, and
is one of the
member types
of the last in the sequence.
The
union
datatypes in this sequence are said to
intervene
between
and
. When
and
are given by the context, the datatypes
in the sequence are referred to as the
intervening unions
When
is one of the
member types
of
the set of
intervening unions
is the empty set.
[Definition:]
In a valid
instance of any
union
, the first of its members in order which
accepts the instance as valid is the
active member
type
[Definition:]
If the
active member type
is
itself a
union
, one of
its
members will be
its
active member type
, and so on, until
finally a
basic (non-union)
member
is reached. That
basic member
is
the
active basic member
of the union.
The order in which the
member types
are specified in the
definition (that is, in the case of
datatypes defined in a schema document, the order of the
of the
QName
s in the
memberTypes
attribute) is
significant. During validation, an element or attribute's value is
validated against the
member types
in the order in which they appear
in the definition until a match is found. As noted above,
the evaluation order can be overridden with the use of
xsi:type
Example
For example, given the definition below, the first instance of the
validates correctly as an
integer (§3.4.13)
, the second and third as
string (§3.3.1)
The
canonical mapping
of
union
datatype maps each value onto the
canonical representation
of that value obtained
using the
canonical mapping
of the first
member type
in whose value space it lies.
When a datatype is
derived
by
restricting
union
datatype, the following
constraining facets
apply:
enumeration
pattern
assertions
2.4.2 Special vs. Primitive vs.
Ordinary
Datatypes
Next, we distinguish
special
primitive
, and
ordinary
(or
constructed
) datatypes.
Each
datatype defined by or in accordance
with this specification falls
into exactly one of these
categories.
[Definition:]
The
special
datatypes are
anySimpleType
and
anyAtomicType
They are special by virtue of their
position in the type hierarchy.
[Definition:]
Primitive
datatypes are those
datatypes that are not
special
and are
not defined in terms of other datatypes;
they exist
ab initio
All
primitive
datatypes have
anyAtomicType
as their
base type
, but their
value
and
lexical spaces
must be given in prose; they cannot be described as
restrictions
of
anyAtomicType
by the application of particular
constraining facets
Note:
As normatively specified elsewhere,
conforming processors
must
support all the
primitive datatypes defined in this specification; it is
implementation-defined
whether other primitive datatypes are
supported.
Processors
may
, for example,
support the floating-point decimal datatype specified in
[Precision Decimal]
[Definition:]
Ordinary
datatypes are all datatypes other than the
special
and
primitive
datatypes.
Ordinary
datatypes
can be understood fully in terms of their
Simple Type Definition
and
the properties of the datatypes from which they are
constructed
For example, in this specification,
float
is a
primitive
datatype based on
a well-defined mathematical concept
and
not
defined in terms of other datatypes, while
integer
is
constructed
from the more general datatype
decimal
2.4.2.1 Facet-based Restriction
[Definition:]
datatype is defined by
facet-based restriction
of another datatype
(its
base type
),
when values for zero or more
constraining facets
are specified
that serve to constrain its
value space
and/or its
lexical space
to a subset of those of the
base type
The
base type
of a
facet-based restriction
must
be a
primitive
or
ordinary
datatype.
2.4.2.2 Construction by List
list
datatype can be
constructed
from another datatype (its
item type
) by creating
value space
that consists of
finite-length sequences
of zero or more values of its
item type
Datatypes so
constructed
have
anySimpleType
as their
base type
Note that since the
value space
and
lexical space
of any
list
datatype are necessarily subsets of the
value space
and
lexical space
of
anySimpleType
, any datatype
constructed
as a
list
is a
restriction
of its base type.
2.4.2.3 Construction by Union
One datatype can be
constructed
from one or more
datatypes
by
unioning
their
lexical mappings
and, consequently, their
value spaces
and
lexical spaces
Datatypes so
constructed
also have
anySimpleType
as their
base type
Note that since the
value space
and
lexical space
of any
union
datatype are necessarily subsets of the
value space
and
lexical space
of
anySimpleType
, any datatype
constructed
as a
union
is a
restriction
of its base type.
2.4.3 Definition, Derivation, Restriction, and Construction
Definition, derivation, restriction, and construction
are conceptually distinct, although in practice
they are frequently performed by the same mechanisms.
By 'definition' is meant the explicit
identification of the relevant properties of a datatype,
in particular its
value space
lexical space
, and
lexical mapping
The properties of the
special
and the
standard
primitive
datatypes are defined by this
specification. A
Simple Type Definition
is present for each of these
datatypes in every valid schema; it serves as a representation of the
datatype, but by itself it does not capture all the relevant
information and does not suffice (without knowledge
of this specification) to
define
the datatype.
Note:
The properties of any
implementation-defined
primitive
datatypes are given not here but in the documentation for
the implementation in question.
Alternatively, a primitive datatype
not specified in this document can be specified in a document
of its own not tied to a particular implementation;
[Precision Decimal]
is an example of such a document.
For all other datatypes, a
Simple Type Definition
does suffice.
The properties of an
ordinary
datatype can be inferred
from the datatype's
Simple Type Definition
and the properties of
the
base type
item type
if any, and
member types
if any.
All
ordinary
datatypes can be defined in this way.
By 'derivation' is meant the relation of
a datatype to its
base type
, or to the
base type
of its
base type
and so on.
Every datatype
other than
anySimpleType
is associated with another datatype, its
base type
Base types
can be
special
primitive
, or
ordinary
[Definition:]
A datatype
is
immediately derived
from another datatype
if and only if
is the
base type
of
Note:
The above does not preclude the
Simple Type Definition
for
anySimpleType
from having a value for
its
{base type definition}
(It does, and its value is
anyType
.)
More generally,
A datatype
is
derived
from another
datatype
if and only if one of the following is true:
is the
base type
of
There is some datatype
such that
is the
base type
of
, and
is derived from
A datatype
must not
be
derived
from itself. That is, the
base type relation must be acyclic.
It is a consequence of the above
that every datatype other than
anySimpleType
is
derived
from
anySimpleType
Since each datatype has exactly one
base type
and every datatype other
than
anySimpleType
is
derived
directly or
indirectly from
anySimpleType
, it follows that
the
base type
relation arranges all
simple types into a tree structure, which is conventionally
referred to as the
derivation hierarchy
By 'restriction' is meant the definition
of a datatype whose
value space
and
lexical space
are
subsets of those of its
base type
Formally,
A datatype
is a
restriction
of another
datatype
when
the
value space
of
is a subset of the
value space
of
, and
the
lexical space
of
is a subset of the
lexical space
of
Note that all three forms of datatype
construction
produce
restrictions
of the
base type
facet-based restriction
does so by means of
constraining facets
while
construction
by
list
or
union
does so because those
constructions
take
anySimpleType
as the
base type
. It follows that all
datatypes are
restrictions
of
anySimpleType
This specification provides no means by which a datatype may be
defined so as to have a larger
lexical space
or
value space
than its
base type
By 'construction' is meant the creation of a
datatype by defining it in terms of another.
[Definition:]
All
ordinary
datatypes are defined in terms of, or
constructed
from, other datatypes, either by
restricting
the
value space
or
lexical space
of a
base type
using zero or more
constraining facets
or by specifying the new datatype as a
list
of items of some
item type
or by defining it as a
union
of some specified
sequence of
member types
These three forms of
construction
are often called "
facet-based restriction
",
construction
by
list
", and "
construction
by
union
", respectively.
Datatypes so constructed may be understood fully (for
purposes of a type system) in terms of (a) the properties
of the datatype(s) from which they are constructed, and
(b) their
Simple Type Definition
. This distinguishes
ordinary
datatypes
from the
special
and
primitive
datatypes, which can be understood
only in the light of documentation (namely, their descriptions
elsewhere in this specification,
or, for
implementation-defined
primitives
, in the appropriate
implementation-specific documentation).
All
ordinary
datatypes are
constructed
, and all
constructed
datatypes are
ordinary
2.4.4 Built-in vs. User-Defined Datatypes
[Definition:]
Built-in
datatypes are those which are defined in this
specification; they can
be
special
primitive
, or
ordinary
datatypes
[Definition:]
User-defined
datatypes are those
datatypes that are defined by individual schema designers.
The
built-in
datatypes are intended to be
available automatically whenever this specification is implemented or
used, whether by itself or embedded in a host language. In the
language defined by
[XSD 1.1 Part 1: Structures]
the
built-in
datatypes are automatically
included in every valid schema. Other host languages
should
specify
that all of the datatypes decribed here as built-ins are automatically
available; they
may
specify that additional datatypes are also made
available automatically.
Note:
Implementation-defined
datatypes, whether
primitive
or
ordinary
may sometimes
be included automatically in any schemas processed
by that implementation; nevertheless, they are not built in
to
every
schema, and are thus not included
in the term 'built-in', as that term is
used in this specification.
The mechanism for making
user-defined
datatypes available for use is not defined in this specification; if
user-defined
datatypes are to be available, some such mechanism
must
be specified by the host language.
[Definition:]
datatype which is not available for use is said to be
unknown
Note:
From the schema author's perspective, a reference to
a datatype which proves to be
unknown
might reflect
any of the following causes, or others:
An error has been made in giving the name of the datatype.
The datatype is a
user-defined
datatype which has not been made
available using the means defined by the host language (e.g.
because the appropriate schema document has not been
consulted).
The datatype is an
implementation-defined
primitive
datatype not supported by the implementation being
used.
The datatype is an
implementation-defined
ordinary
datatype which is made automatically available by some
implementations, but not by the implementation being
used.
The datatype is a
user-defined
ordinary
datatype
whose base type is
unknown
From the point of view of the implementation, these cases
are likely to be indistinguishable.
Note:
In the terminology of
[XSD 1.1 Part 1: Structures]
the datatypes here called
unknown
are referred to as
absent
Conceptually there is no difference between the
ordinary
built-in
datatypes included in this specification and the
user-defined
datatypes which will be created by individual schema designers.
The
built-in
constructed
datatypes
are those which are believed to be so common that if they were not
defined in this specification many schema designers would end up
reinventing them. Furthermore, including these
constructed
datatypes in this specification serves to
demonstrate the mechanics and utility of the datatype generation
facilities of this specification.
3 Built-in Datatypes and Their Definitions
Diagram showing the derivation relations in the built-in type hierarchy.
(A
long description of the diagram
is available separately.)
Each built-in datatype defined
in this specification can be uniquely addressed via a
URI Reference constructed as follows:
the base URI is the URI of the XML Schema namespace
the fragment identifier is the name of the datatype
For example, to address the
int
datatype, the URI is:
Additionally, each facet definition element can be uniquely
addressed via a URI constructed as follows:
the base URI is the URI of the XML Schema namespace
the fragment identifier is the name of the facet
For example, to address the maxInclusive facet, the URI is:
Additionally, each facet usage in a built-in
Simple Type Definition
can be uniquely addressed via a URI constructed as follows:
the base URI is the URI of the XML Schema namespace
the fragment identifier is the name of the
Simple Type Definition
, followed
by a period ('
') followed by the name of the facet
For example, to address the usage of the maxInclusive facet in
the definition of int, the URI is:
3.1 Namespace considerations
The
built-in
datatypes defined by this specification
are designed to be used with the XML Schema definition language as well as other
XML specifications.
To facilitate usage within the XML Schema definition language, the
built-in
datatypes in this specification have the namespace name:
To facilitate usage in specifications other than the XML Schema definition language,
such as those that do not want to know anything about aspects of the
XML Schema definition language other than the datatypes, each
built-in
datatype is also defined in the namespace whose URI is:
Each
user-defined
datatype may also be associated with a
target
namespace. If it is constructed
from a schema document, then its namespace is typically the
target namespace of that schema document. (See
XML Representation of
Schemas
in
[XSD 1.1 Part 1: Structures]
.)
3.2 Special Built-in Datatypes
3.2.1
anySimpleType
3.2.1.1
Value space
3.2.1.2
Lexical mapping
3.2.1.3
Facets
3.2.2
anyAtomicType
3.2.2.1
Value space
3.2.2.2
Lexical mapping
3.2.2.3
Facets
The two datatypes at the root of the hierarchy of simple
types are
anySimpleType
and
anyAtomicType
3.2.1 anySimpleType
The definition of
anySimpleType
is a special
restriction
of
anyType
The
lexical space
of
anySimpleType
is the set of all sequences of Unicode
characters,
and its
value space
includes all
atomic values
and all finite-length lists of
zero or more
atomic values
For further details of
anySimpleType
and its representation as a
Simple Type Definition
, see
Built-in Simple Type Definitions (§4.1.6)
3.2.1.1 Value space
The
value space
of
anySimpleType
is the set of all
atomic values
and of all finite-length
lists of zero or more
atomic values
Note:
It is a consequence of this definition, together with the
definition of the
lexical mapping
in the next section, that some
values of this datatype have no
lexical representation
using the
lexical mappings
defined by this specification. That is, the
"potential"
value space
and the "effable"
or "nameable"
value space
diverge for this datatype.
As far as this specification is concerned, there is no operational
difference between the potential and effable
value spaces
and the
distinction is of mostly formal interest. Since some host languages
for the type system defined here may allow means of construction
values other than mapping from a
lexical representation
, the
difference may have practical importance in some contexts. In those
contexts, the term
value space
should unless otherwise qualified be
taken to mean the potential
value space
3.2.1.2 Lexical mapping
The
lexical space
of
anySimpleType
is the set of
all finite-length sequences of zero or more
character
s (as
defined in
[XML]
) that
match
the
Char
production from
[XML]
. This is equivalent to the union of the
lexical spaces
of all
primitive
and all possible
ordinary
datatypes.
It is
implementation-defined
whether an
implementation of this specification supports the
Char
production from
[XML]
, or that from
[XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
The
lexical mapping
of
anySimpleType
is the union
of the
lexical mappings
of
all
primitive
datatypes and all list datatypes.
It will be noted that this mapping is not a function: a given
literal
may map to one value or to several values of different
primitive
datatypes, and it may be indeterminate which value is to
be preferred in a particular context. When the datatypes defined here
are used in the context of
[XSD 1.1 Part 1: Structures]
, the
xsi:type
attribute defined by that specification in section
xsi:type
can be used
to indicate which value a
literal
which is the content of an element
should map to. In other contexts, other rules (such as type coercion
rules) may be employed to determine which value is to be used.
3.2.1.3 Facets
When a new datatype is defined
by
facet-based restriction
anySimpleType
must not
be used
as the
base type
So no
constraining facets
are
directly applicable to
anySimpleType
3.2.2 anyAtomicType
[Definition:]
anyAtomicType
is a special
restriction
of
anySimpleType
The
value
and
lexical spaces
of
anyAtomicType
are the unions of the
value
and
lexical spaces
of all the
primitive
datatypes, and
anyAtomicType
is their
base type
For further details of
anyAtomicType
and its representation as a
Simple Type Definition
, see
Built-in Simple Type Definitions (§4.1.6)
3.2.2.1 Value space
The
value space
of
anyAtomicType
is the union of the
value spaces
of all the
primitive
datatypes defined here
or supplied as
implementation-defined
primitives
3.2.2.2 Lexical mapping
The
lexical space
of
anyAtomicType
is the set of
all finite-length sequences of zero or more
character
s (as
defined in
[XML]
) that
match
the
Char
production from
[XML]
. This is equivalent to the union of the
lexical spaces
of all
primitive
datatypes.
It is
implementation-defined
whether an
implementation of this specification supports the
Char
production from
[XML]
, or that from
[XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
The
lexical mapping
of
anyAtomicType
is the union
of the
lexical mappings
of
all
primitive
datatypes.
It will be noted that this mapping is not a function: a given
literal
may map to one value or to several values of different
primitive
datatypes, and it may be indeterminate which value is to
be preferred in a particular context. When the datatypes defined here
are used in the context of
[XSD 1.1 Part 1: Structures]
, the
xsi:type
attribute defined by that specification in section
xsi:type
can be used
to indicate which value a
literal
which is the content of an element
should map to. In other contexts, other rules (such as type coercion
rules) may be employed to determine which value is to be used.
3.2.2.3 Facets
When a new datatype is defined
by
facet-based restriction
anyAtomicType
must not
be used
as the
base type
So no
constraining facets
are
directly applicable to
anyAtomicType
3.3 Primitive Datatypes
3.3.1
string
3.3.1.1
Value Space
3.3.1.2
Lexical Mapping
3.3.1.3
Facets
3.3.1.4
Derived
datatypes
3.3.2
boolean
3.3.2.1
Value Space
3.3.2.2
Lexical Mapping
3.3.2.3
Facets
3.3.3
decimal
3.3.3.1
Lexical
Mapping
3.3.3.2
Facets
3.3.3.3
Datatypes based on decimal
3.3.4
float
3.3.4.1
Value Space
3.3.4.2
Lexical Mapping
3.3.4.3
Facets
3.3.5
double
3.3.5.1
Value Space
3.3.5.2
Lexical Mapping
3.3.5.3
Facets
3.3.6
duration
3.3.6.1
Value Space
3.3.6.2
Lexical Mapping
3.3.6.3
Facets
3.3.6.4
Related Datatypes
3.3.7
dateTime
3.3.7.1
Value Space
3.3.7.2
Lexical Mapping
3.3.7.3
Facets
3.3.7.4
Related Datatypes
3.3.8
time
3.3.8.1
Value Space
3.3.8.2
Lexical Mappings
3.3.8.3
Facets
3.3.9
date
3.3.9.1
Value Space
3.3.9.2
Lexical Mapping
3.3.9.3
Facets
3.3.10
gYearMonth
3.3.10.1
Value Space
3.3.10.2
Lexical
Mapping
3.3.10.3
Facets
3.3.11
gYear
3.3.11.1
Value Space
3.3.11.2
Lexical
Mapping
3.3.11.3
Facets
3.3.12
gMonthDay
3.3.12.1
Value Space
3.3.12.2
Lexical
Mapping
3.3.12.3
Facets
3.3.13
gDay
3.3.13.1
Value Space
3.3.13.2
Lexical Mapping
3.3.13.3
Facets
3.3.14
gMonth
3.3.14.1
Value Space
3.3.14.2
Lexical
Mapping
3.3.14.3
Facets
3.3.15
hexBinary
3.3.15.1
Value Space
3.3.15.2
Lexical Mapping
3.3.15.3
Facets
3.3.16
base64Binary
3.3.16.1
Value Space
3.3.16.2
Lexical
Mapping
3.3.16.3
Facets
3.3.17
anyURI
3.3.17.1
Value Space
3.3.17.2
Lexical
Mapping
3.3.17.3
Facets
3.3.18
QName
3.3.18.1
Facets
3.3.19
NOTATION
3.3.19.1
Facets
The
primitive
datatypes defined by this specification
are described below. For each datatype, the
value space
is described;
the
lexical space
is
defined
using
an extended Backus Naur Format grammar
(and in most cases also a regular expression using the
regular expression language of
Regular Expressions (§G)
);
constraining facets
which apply
to the datatype are listed;
and any datatypes
constructed
from this datatype are specified.
Conforming processors
must
support
the
primitive
datatypes defined
in this specification; it is
implementation-defined
whether they
support others.
Primitive
datatypes may be added by revisions to this specification.
Note:
Processors
may
, for example, support the
floating-point decimal datatype specified in
[Precision Decimal]
3.3.1 string
[Definition:]
The
string
datatype
represents character strings in XML.
Note:
Many human languages have writing systems that require
child elements for control of aspects such as bidirectional formatting or
ruby annotation (see
[Ruby]
and Section 8.2.4
Overriding the
bidirectional algorithm: the BDO element
of
[HTML 4.01]
).
Thus,
string
, as a simple type that can contain only
characters but not child elements, is often not suitable for representing text.
In such situations, a complex type that allows mixed content should be considered.
For more information, see Section 5.5
Any
Element, Any Attribute
of
[XML Schema Language: Part 0 Primer]
3.3.1.1 Value Space
The
value space
of
string
is the set of finite-length sequences of
zero or more
character
s (as defined in
[XML]
) that
match
the
Char
production from
[XML]
character
is an atomic unit of
communication; it is not further specified except to note that every
character
has a corresponding
Universal Character Set (UCS) code point, which is an integer.
It is
implementation-defined
whether an
implementation of this specification supports the
Char
production from
[XML]
, or that from
[XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
Equality for
string
is
identity. No order is prescribed.
Note:
As noted in
ordered
, the fact that this specification does
not specify an
order relation
for
string
does not preclude other applications from treating
strings
as being ordered.
3.3.1.2 Lexical Mapping
The
lexical space
of
string
is the set of
finite-length sequences of zero or more
character
s (as defined in
[XML]
) that
match
the
Char
production from
[XML]
Lexical Space
[1]
stringRep
::=
Char
/*
(as defined in
[XML]
*/
It is
implementation-defined
whether an
implementation of this specification supports the
Char
production from
[XML]
, or that from
[XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
The
lexical mapping
for
string
is
stringLexicalMap
, and
the
canonical mapping
is
stringCanonicalMap
each is a subset of the identity function.
3.3.1.3
Facets
The
string
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
whiteSpace
preserve
Datatypes derived by
restriction from
string
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
string
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.3.1.4 Derived
datatypes
The following
built-in
datatype is
derived
from
string
normalizedString
3.3.2 boolean
[Definition:]
boolean
represents the
values of two-valued logic.
3.3.2.1 Value Space
boolean
has the
value space
of
two-valued logic: {
true
false
}.
3.3.2.2 Lexical Mapping
boolean
's lexical space is a set of four
literals
Lexical Space
[2]
booleanRep
::= '
true
' | '
false
' |
' | '
The
lexical mapping
for
boolean
is
booleanLexicalMap
the
canonical mapping
is
booleanCanonicalMap
3.3.2.3
Facets
The
boolean
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
boolean
may
also
specify values for the
following
constraining facets
pattern
assertions
The
boolean
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
finite
numeric
false
3.3.3 decimal
[Definition:]
decimal
represents
subset of the real numbers, which
can be represented by
decimal numerals.
The
value space
of
decimal
is the set of numbers that can be obtained by
dividing
an integer by a non-negative
power of ten, i.e., expressible as
/ 10
where
and
are integers
and
≥ 0.
Precision is not reflected in this value space;
the number 2.0 is not distinct from the number 2.00.
The order relation on
decimal
is the order relation on real numbers, restricted
to this subset.
Note:
For a decimal datatype whose values do reflect precision, see
[Precision Decimal]
3.3.3.1 Lexical
Mapping
decimal
has
a lexical representation
consisting of a
non-empty finite-length
sequence of
decimal
digits (#x30–#x39) separated
by a period as a decimal indicator.
An optional leading sign is allowed.
If the sign is omitted,
"+"
is assumed. Leading and trailing zeroes are optional.
If the fractional part is zero, the period and following zero(es) can
be omitted.
For example:
-1.23
',
12678967.543233
', '
+100000.00
',
210
'.
The
decimal
Lexical Representation
[3]
decimalLexicalRep
::=
decimalPtNumeral
noDecimalPtNumeral
The lexical space of decimal is the set of
lexical representations which match the grammar given above, or
(equivalently) the regular expression
(\+|-)?([0-9]+(\.[0-9]*)?|\.[0-9]+)
The mapping from lexical representations to values is the usual
one for decimal numerals; it is given formally in
decimalLexicalMap
The definition
of the
canonical representation
has the
effect of prohibiting certain options from the
Lexical
Mapping (§3.3.3.1)
Specifically,
for integers, the decimal point and fractional part are prohibited.
For other values,
the preceding optional
"+"
sign is prohibited. The decimal point is required.
In
all cases, leading and
trailing zeroes are prohibited subject to the following: there
must
be at least one digit to the right and to the left of the decimal
point which may be a
zero.
The mapping from values to
canonical representations
is given formally in
decimalCanonicalMap
3.3.3.2
Facets
The
decimal
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
decimal
may
also
specify values for the
following
constraining facets
totalDigits
fractionDigits
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
decimal
datatype
has the following values for its
fundamental facets
ordered
total
bounded
false
cardinality
countably infinite
numeric
true
3.3.3.3 Datatypes based on decimal
The following
built-in
datatype is
derived
from
decimal
integer
3.3.4 float
[Definition:]
The
float
datatype
is
patterned after the IEEE
single-precision 32-bit floating point datatype
[IEEE 754-2008]
Its
value space is a subset of the
rational numbers. Floating point numbers are often used to
approximate arbitrary real numbers.
3.3.4.1 Value Space
The
value space
of
float
contains the
non-zero numbers
× 2
where
is an integer whose absolute value is less than 2
24
and
is an integer between −149 and 104, inclusive. In addition to
these values, the
value space
of
float
also contains
the following
special values
positiveZero
negativeZero
positiveInfinity
negativeInfinity
, and
notANumber
Note:
As explained below, the
lexical representation
of the
float
value
notANumber
is '
NaN
'. Accordingly, in English
text we generally use 'NaN' to refer to that value. Similarly,
we use 'INF' and '−INF' to refer to the two
values
positiveInfinity
and
negativeInfinity
and '0' and '−0' to refer to
positiveZero
and
negativeZero
Equality and order for
float
are defined as follows:
Equality is identity, except that 0 = −0 (although
they are not identical) and NaN ≠ NaN
(although NaN is of course identical to itself).
0 and −0 are thus equivalent
for purposes of enumerations and
identity constraints, as well as for minimum and maximum values.
For the basic values, the order relation
on float is the order relation for rational numbers. INF is greater
than all other non-NaN values; −INF is less than all other non-NaN
values. NaN is
incomparable
with any value
in the
value space
including itself. 0 and −0
are greater than all the negative numbers and less than all the positive
numbers.
Note:
Any value
incomparable
with the value used for the four
bounding facets (
minInclusive
maxInclusive
minExclusive
, and
maxExclusive
) will be
excluded from the resulting restricted
value space
In particular, when NaN is used as a facet value for a bounding facet, since no
float
values are
comparable
with it, the result is a
value space
that is empty.
If any other value is used for a bounding facet,
NaN will be excluded from the resulting restricted
value space
to add NaN back in requires union with the NaN-only space (which
may be derived using
the
pattern '
NaN
').
Note:
The Schema 1.0 version of this datatype did not differentiate between
0 and −0 and NaN was equal to itself. The changes were
made to make the datatype more closely mirror
[IEEE 754-2008]
3.3.4.2 Lexical Mapping
The
lexical space
of
float
is
the set of all decimal numerals with or without a decimal
point, numerals in scientific (exponential) notation, and
the
literals
INF
', '
+INF
',
-INF
',
and '
NaN
Lexical Space
[4]
floatRep
::=
noDecimalPtNumeral
decimalPtNumeral
scientificNotationNumeral
numericalSpecialRep
The
floatRep
production is equivalent to this regular
expression (after whitespace is
removed from the regular expression):
(\+|-)?([0-9]+(\.[0-9]*)?|\.[0-9]+)([Ee](\+|-)?[0-9]+)?
|(\+|-)?INF|NaN
The
float
datatype is designed to implement for schema
processing the single-precision floating-point datatype of
[IEEE 754-2008]
. That specification does not specify specific
lexical representations
but does prescribe requirements on any
lexical mapping
used. Any
lexical mapping
that maps the
lexical space
just described onto the
value space
, is a function,
satisfies the requirements of
[IEEE 754-2008]
, and correctly handles the
mapping of the literals
INF
', '
NaN
', etc., to the
special values
satisfies the conformance requirements of this specification.
Since IEEE allows some variation in rounding of values, processors
conforming to this specification may exhibit some variation in their
lexical mappings
The
lexical mapping
floatLexicalMap
is
provided as an example of a simple algorithm that yields a conformant mapping,
and that provides the most accurate rounding possible—and is thus useful
for insuring inter-implementation reproducibility and inter-implementation
round-tripping. The simple rounding
algorithm used in
floatLexicalMap
may be more efficiently
implemented using the algorithms of
[Clinger, WD (1990)]
Note:
The Schema 1.0 version of this datatype did not permit rounding
algorithms whose results differed from
[Clinger, WD (1990)]
The
canonical mapping
floatCanonicalMap
is
provided as an example of a mapping that does not produce unnecessarily long
canonical representations
Other algorithms which do not yield identical results for mapping from float
values to character strings are permitted by
[IEEE 754-2008]
3.3.4.3
Facets
The
float
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
float
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
float
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
true
cardinality
finite
numeric
true
3.3.5 double
[Definition:]
The
double
datatype is
patterned after the
IEEE double-precision 64-bit floating point datatype
[IEEE 754-2008]
Each floating
point datatype has a value space that is a subset of the
rational numbers. Floating point numbers are often used to
approximate arbitrary real numbers.
Note:
The only significant differences between float and double are
the three defining constants 53 (vs 24), −1074 (vs −149),
and 971 (vs 104).
3.3.5.1 Value Space
The
value space
of
double
contains the
non-zero numbers
× 2
where
is an integer whose absolute value is less than 2
53
and
is an integer between −1074 and 971, inclusive. In addition to
these values, the
value space
of
double
also contains
the following
special values
positiveZero
negativeZero
positiveInfinity
negativeInfinity
, and
notANumber
Note:
As explained below, the
lexical representation
of the
double
value
notANumber
is '
NaN
'. Accordingly, in English
text we generally use 'NaN' to refer to that value. Similarly,
we use 'INF' and '−INF' to refer to the two
values
positiveInfinity
and
negativeInfinity
and '0' and '−0' to refer to
positiveZero
and
negativeZero
Equality and order for
double
are defined as follows:
Equality is identity, except that 0 = −0 (although
they are not identical) and NaN ≠ NaN
(although NaN is of course identical to itself).
0 and −0 are thus equivalent for purposes of enumerations,
identity constraints, and minimum and maximum values.
For the basic values, the order relation
on double is the order relation for rational numbers. INF is greater
than all other non-NaN values; −INF is less than all other non-NaN
values. NaN is
incomparable
with any value
in the
value space
including itself. 0 and −0
are greater than all the negative numbers and less than all the positive
numbers.
Note:
Any value
incomparable
with the value used for the four
bounding facets (
minInclusive
maxInclusive
minExclusive
, and
maxExclusive
) will be
excluded from the resulting restricted
value space
In particular, when NaN is used as a facet value for a bounding facet, since no
double
values are
comparable
with it, the result is a
value space
that is empty.
If any other value is used for a bounding facet,
NaN will be excluded from the resulting restricted
value space
to add NaN back in requires union with the NaN-only space (which
may be derived using
the
pattern '
NaN
').
Note:
The Schema 1.0 version of this datatype did not differentiate between
0 and −0 and NaN was equal to itself. The changes were
made to make the datatype more closely mirror
[IEEE 754-2008]
3.3.5.2 Lexical Mapping
The
lexical space
of
double
is
the set of all decimal numerals with or without a decimal
point, numerals in scientific (exponential) notation, and
the
literals
INF
', '
+INF
',
-INF
', and '
NaN
Lexical Space
[5]
doubleRep
::=
noDecimalPtNumeral
decimalPtNumeral
scientificNotationNumeral
numericalSpecialRep
The
doubleRep
production is equivalent to this regular
expression
(after whitespace is eliminated from the expression):
(\+|-)?([0-9]+(\.[0-9]*)?|\.[0-9]+)([Ee](\+|-)?[0-9]+)?
|(\+|-)?INF|NaN
The
double
datatype is designed to implement for schema
processing the double-precision floating-point datatype of
[IEEE 754-2008]
. That specification does not specify specific
lexical representations
but does prescribe requirements on any
lexical mapping
used. Any
lexical mapping
that maps the
lexical space
just described onto the
value space
, is a function,
satisfies the requirements of
[IEEE 754-2008]
, and correctly handles the
mapping of the literals
INF
', '
NaN
', etc., to the
special values
satisfies the conformance requirements of this specification.
Since IEEE allows some variation in rounding of values, processors
conforming to this specification may exhibit some variation in their
lexical mappings
The
lexical mapping
doubleLexicalMap
is
provided as an example of a simple algorithm that yields a conformant mapping,
and that provides the most accurate rounding possible—and is thus useful
for insuring inter-implementation reproducibility and inter-implementation
round-tripping. The simple rounding
algorithm used in
doubleLexicalMap
may be more efficiently
implemented using the algorithms of
[Clinger, WD (1990)]
Note:
The Schema 1.0 version of this datatype did not permit rounding
algorithms whose results differed from
[Clinger, WD (1990)]
The
canonical mapping
doubleCanonicalMap
is
provided as an example of a mapping that does not produce unnecessarily long
canonical representations
Other algorithms which do not yield identical results for mapping from float values
to character strings are permitted by
[IEEE 754-2008]
3.3.5.3
Facets
The
double
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
double
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
double
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
true
cardinality
finite
numeric
true
3.3.6 duration
[Definition:]
duration
is a datatype that represents
durations of time.
The concept of duration being captured is
drawn from those of
[ISO 8601]
, specifically
durations without fixed endpoints
. For example,
"15 days" (whose most common lexical representation
in
duration
is "'
P15D
'") is
duration
value; "15 days beginning 12 July
1995" and "15 days ending 12 July 1995" are
not
duration
values.
duration
can provide addition and
subtraction operations between
duration
values and
between
duration
dateTime
value pairs,
and can be the result of subtracting
dateTime
values. However, only addition to
dateTime
is required for XML Schema processing and is
defined in
the function
dateTimePlusDuration
3.3.6.1 Value Space
Duration values can be modelled as
two-property tuples. Each value consists of an integer number of
months and a decimal number of seconds. The
seconds
value
must not
be negative if the
months
value is positive and
must not
be
positive if the
months
is negative.
Properties of
duration
Values
months
integer
seconds
decimal
value;
must not
be negative if
months
is positive, and
must not
be positive if
months
is negative.
duration
is partially ordered.
Equality of
duration
is defined in terms of equality of
dateTime
; order for
duration
is defined in terms of the order of
dateTime
. Specifically, the equality or order of
two
duration
values is determined by adding each
duration
in the pair to each of the following
four
dateTime
values:
1696-09-01T00:00:00Z
1697-02-01T00:00:00Z
1903-03-01T00:00:00Z
1903-07-01T00:00:00Z
If all four resulting
dateTime
value pairs are ordered
the same way (less than, equal, or greater than), then the original
pair of
duration
values is ordered the same way;
otherwise the original pair is
incomparable
Note:
These four values are chosen so as to maximize
the possible differences in results that could occur,
such as the difference when adding P1M and P30D:
1697-02-01T00:00:00Z + P1M < 1697-02-01T00:00:00Z + P30D ,
but
1903-03-01T00:00:00Z + P1M > 1903-03-01T00:00:00Z + P30D ,
so that P1M <> P30D .
If two
duration
values are ordered the same way
when added to each of these four
dateTime
values,
they will retain the same order when added
to
any
other
dateTime
values. Therefore,
two
duration
values are incomparable if and only
if they can
ever
result in different orders when added to
any
dateTime
value.
Under the definition just given,
two
duration
values are equal if and only if they are identical.
Note:
Two totally ordered datatypes (
yearMonthDuration
and
dayTimeDuration
) are derived from
duration
in
Other Built-in Datatypes (§3.4)
Note:
There are many ways to implement
duration
some of which do not base the implementation on the two-component
model. This specification does not prescribe any particular
implementation, as long as the visible results are isomorphic to those
described herein.
Note:
See the conformance notes in
Partial Implementation of Infinite Datatypes (§5.4)
, which
apply to this datatype.
3.3.6.2 Lexical Mapping
The
lexical representations
of
duration
are
more or less based on the pattern:
DT
More precisely, the
lexical space
of
duration
is the set of character
strings that satisfy
durationLexicalRep
as defined by the following productions:
Lexical Representation Fragments
[6]
duYearFrag
::=
unsignedNoDecimalPtNumeral
[7]
duMonthFrag
::=
unsignedNoDecimalPtNumeral
[8]
duDayFrag
::=
unsignedNoDecimalPtNumeral
[9]
duHourFrag
::=
unsignedNoDecimalPtNumeral
[10]
duMinuteFrag
::=
unsignedNoDecimalPtNumeral
[11]
duSecondFrag
::= (
unsignedNoDecimalPtNumeral
unsignedDecimalPtNumeral
) '
[12]
duYearMonthFrag
::= (
duYearFrag
duMonthFrag
?) |
duMonthFrag
[13]
duTimeFrag
::= '
' ((
duHourFrag
duMinuteFrag
duSecondFrag
?) |
duMinuteFrag
duSecondFrag
?) |
duSecondFrag
[14]
duDayTimeFrag
::= (
duDayFrag
duTimeFrag
?) |
duTimeFrag
Lexical Representation
[15]
durationLexicalRep
::= '
'? '
' ((
duYearMonthFrag
duDayTimeFrag
?) |
duDayTimeFrag
Thus, a
durationLexicalRep
consists of one or more of a
duYearFrag
duMonthFrag
duDayFrag
duHourFrag
duMinuteFrag
, and/or
duSecondFrag
, in order, with letters
' and '
' (and perhaps a '
')
where appropriate.
The language accepted by the
durationLexicalRep
production is the set of strings which satisfy all of the following
three regular expressions:
The expression
-?P[0-9]+Y?([0-9]+M)?([0-9]+D)?(T([0-9]+H)?([0-9]+M)?([0-9]+(\.[0-9]+)?S)?)?
matches only strings in which the fields occur in the proper order.
The expression '
.*[YMDHS].*
' matches only
strings in which at least one field occurs.
The expression '
.*[^T]
' matches
only strings in which '
' is not the final character, so that
if '
' appears, something follows it. The first rule
ensures that what follows '
' will be an hour,
minute, or second field.
The intersection of these three regular expressions is equivalent to
the following (after removal of the white space inserted here for
legibility):
-?P( ( ( [0-9]+Y([0-9]+M)?([0-9]+D)?
| ([0-9]+M)([0-9]+D)?
| ([0-9]+D)
(T ( ([0-9]+H)([0-9]+M)?([0-9]+(\.[0-9]+)?S)?
| ([0-9]+M)([0-9]+(\.[0-9]+)?S)?
| ([0-9]+(\.[0-9]+)?S)
)?
| (T ( ([0-9]+H)([0-9]+M)?([0-9]+(\.[0-9]+)?S)?
| ([0-9]+M)([0-9]+(\.[0-9]+)?S)?
| ([0-9]+(\.[0-9]+)?S)
The
lexical mapping
for
duration
is
durationMap
The canonical
mapping
for
duration
is
durationCanonicalMap
3.3.6.3
Facets
The
duration
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
duration
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
duration
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.6.4 Related Datatypes
The following
built-in
datatypes are
derived
from
duration
yearMonthDuration
dayTimeDuration
3.3.7 dateTime
dateTime
represents
instants of time, optionally marked
with a particular time zone offset. Values representing
the same instant but having
different time zone offsets are equal but not
identical.
3.3.7.1 Value Space
dateTime
uses the
date/timeSevenPropertyModel
, with no properties
except
timezoneOffset
permitted
to be
absent
. The
timezoneOffset
property remains
optional
Note:
In version 1.0 of this specification, the
year
property was not permitted to have the value
zero. The year before the year 1
in the proleptic Gregorian calendar, traditionally referred to as
1 BC or as
1 BCE, was represented by a
year
value of −1, 2 BCE by −2, and so
forth. Of course, many, perhaps most,
references to 1 BCE (or 1 BC) actually refer not
to a year in the proleptic Gregorian calendar but to a year in the
Julian or "old style" calendar; the two correspond
approximately but not exactly to each other.
In this version of this specification,
two changes are made in order to agree with existing usage.
First,
year
is permitted to have the value zero.
Second, the interpretation of
year
values is changed accordingly: a
year
value of zero represents 1 BCE, −1
represents 2 BCE, etc. This representation simplifies interval
arithmetic and leap-year calculation for dates before the common
era (which may be why astronomers
and others interested in such calculations with the proleptic
Gregorian calendar have adopted it), and is consistent with the
current edition of
[ISO 8601]
Note that 1 BCE, 5 BCE, and so on (years 0000, -0004, etc. in the
lexical representation defined here) are leap years in the proleptic
Gregorian calendar used for the date/time datatypes defined here.
Version 1.0 of this specification was unclear about the treatment of
leap years before the common era.
If existing
schemas or data specify dates of 29 February for any years before the
common era, then some values giving
a date of 29 February which were valid under a plausible
interpretation of XSD 1.0 will be invalid under this specification,
and some which were invalid will be valid. With that possible
exception, schemas and data valid
under the old interpretation remain valid under the new.
Constraint: Day-of-month Values
The
day
value
must
be
no more than 30 if
month
is one of 4, 6, 9, or 11;
no more than 28
if
month
is 2 and
year
is not divisible by 4,
or is divisible by 100 but not by 400;
and no more than 29 if
month
is 2 and
year
is divisible by 400, or by 4 but not by 100.
Note:
See the conformance note in
Partial Implementation of Infinite Datatypes (§5.4)
which applies to the
year
and
second
values of this datatype.
Equality and order are as prescribed
in
The Seven-property Model (§D.2.1)
dateTime
values are ordered
by their
timeOnTimeline
value.
Note:
Since the order of a
dateTime
value having a
timezoneOffset
relative to another value whose
timezoneOffset
is
absent
is determined
by imputing time zone offsets of both +14:00
and −14:00 to the
value with no time zone offset, many such
combinations will be
incomparable
because the two imputed
time zone offsets yield different orders.
Although
dateTime
and other
types related to dates and times have only a partial order, it
is possible for datatypes derived from
dateTime
to have
total orders, if they are restricted (e.g. using the
pattern
facet) to the subset of values with, or
the subset of values without, time zone offsets. Similar restrictions
on other date- and time-related types will similarly produce
totally ordered subtypes. Note, however, that
such restrictions do not affect the value shown, for a given
Simple Type Definition
, in the
ordered
facet.
Note:
Order and equality are essentially the same for
dateTime
in this version of this specification as
they were in version 1.0. However, since values
now distinguish time zone offsets, equal
values with different
timezoneOffset
are not
identical
, and values with extreme
timezoneOffset
s may no longer be equal
to any value with a smaller
timezoneOffset
3.3.7.2 Lexical Mapping
The lexical representations for
dateTime
are as follows:
Lexical Space
[16]
dateTimeLexicalRep
::=
yearFrag
monthFrag
dayFrag
' ((
hourFrag
minuteFrag
secondFrag
) |
endOfDayFrag
timezoneFrag
Constraint:
Day-of-month Representations
Constraint: Day-of-month Representations
Within a
dateTimeLexicalRep
, a
dayFrag
must not
begin with the digit '
' or be '
29
unless the value to
which it would map would satisfy the value constraint on
day
values
("Constraint: Day-of-month Values") given above.
In such representations:
yearFrag
is a numeral consisting
of at least four decimal digits, optionally preceded by a minus sign;
leading '
' digits are prohibited except to bring the
digit count up to four.
It represents the
year
value.
Subsequent '
', '
', and
', separate the various numerals.
monthFrag
dayFrag
hourFrag
and
minuteFrag
are numerals consisting
of exactly two decimal digits.
They represent
the
month
day
hour
, and
minute
values
respectively.
secondFrag
is a numeral consisting
of exactly two decimal digits, or two decimal digits,
a decimal point, and one or more trailing digits.
It represents the
second
value.
Alternatively,
endOfDayFrag
combines the
hourFrag
minuteFrag
minuteFrag
, and their separators to
represent midnight of the day, which is the first moment of the next
day.
timezoneFrag
, if present, specifies an
offset between UTC and local time.
Time zone offsets are a count of minutes (expressed in
timezoneFrag
as a count of hours and minutes) that are added
or subtracted from UTC time to get the "local" time.
' is an alternative representation of the time zone offset
00:00
',
which is, of course, zero minutes from UTC.
For example, 2002-10-10T12:00:00−05:00
(noon on 10 October 2002, Central Daylight
Savings Time as well as Eastern Standard Time
in the U.S.) is equal to 2002-10-10T17:00:00Z,
five hours later than 2002-10-10T12:00:00Z.
Note:
For the most part, this specification adopts the distinction between
'timezone' and 'timezone offset' laid
out in
[Timezones]
Version 1.0 of this specification did not make this distinction,
but used the term 'timezone' for the time zone
offset information associated with date- and time-related datatypes.
Some traces of the earlier usage remain visible in this and other
specifications. The names
timezoneFrag
and
explicitTimezone
are such traces ;
others will be found in the names of functions defined in
[XQuery 1.0 and XPath 2.0 Functions and Operators]
, or in references in this specification to
"timezoned" and "non-timezoned"
values.
The
dateTimeLexicalRep
production
is equivalent to this regular expression
once whitespace is removed.
-?([1-9][0-9]{3,}|0[0-9]{3})
-(0[1-9]|1[0-2])
-(0[1-9]|[12][0-9]|3[01])
T(([01][0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9](\.[0-9]+)?|(24:00:00(\.0+)?))
(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
Note that neither the
dateTimeLexicalRep
production
nor this regular
expression alone enforce the constraint
on
dateTimeLexicalRep
given above.
The
lexical mapping
for
dateTime
is
dateTimeLexicalMap
The
canonical mapping
is
dateTimeCanonicalMap
3.3.7.3
Facets
The
dateTime
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
dateTime
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
dateTime
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
dateTime
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.7.4 Related Datatypes
The following
built-in
datatype is
derived
from
dateTime
dateTimeStamp
3.3.8 time
time
represents instants of time that recur at the same point in each
calendar day, or that occur in some arbitrary calendar day.
3.3.8.1 Value Space
time
uses the
date/timeSevenPropertyModel
, with
year
month
and
day
required
to be
absent
timezoneOffset
remains
optional
Note:
See the conformance note in
Partial Implementation of Infinite Datatypes (§5.4)
which applies to the
second
value of this datatype.
Equality and order are as prescribed in
The Seven-property Model (§D.2.1)
time
values
(points in time in an "arbitrary" day) are ordered
taking into account their
timezoneOffset
A calendar (or
"local time") day with a larger positive
time zone offset begins earlier than the same calendar day with
a smaller (or negative)
time zone offset. Since the time zone offsets allowed spread over 28 hours,
it is
possible for the period denoted by a given calendar day with one
time zone offset to be completely disjoint from the period denoted by
the same calendar day with a different offset
— the earlier day ends before the
later one starts.
The moments in time
represented by a single calendar day are spread over a 52-hour
interval, from the beginning of the day in the +14:00 time zone offset to the
end of that day in the −14:00 time zone offset.
Note:
The relative
order of two
time
values, one of which has a
timezoneOffset
of
absent
is determined by imputing
time zone offsets of both +14:00 and −14:00 to the value without an offset. Many such combinations will be
incomparable
because the two imputed time zone offsets yield
different orders. However, for a given non-timezoned value,
there will always be timezoned values at one or both ends of the
52-hour interval that are
comparable
(because the interval of
incomparability
is only
28
hours wide).
Some pairs of
time
literals
which
in the 1.0 version of this specification
denoted the same value
now (in this version) denote distinct values instead,
because values now include time zone offset information.
Some such pairs,
such as '
05:00:00-03:00
' and '
10:00:00+02:00
',
now denote equal though distinct values
(because they identify the same points on the time line);
others,
such as '
23:00:00-03:00
' and '
02:00:00Z
',
now denote unequal values (23:00:00−03:00 > 02:00:00Z
because 23:00:00−03:00 on any given day is equal to
02:00:00Z on
the next day
).
3.3.8.2 Lexical Mappings
The lexical representations for
time
are "projections" of
those of
dateTime
, as follows:
Lexical Space
[17]
timeLexicalRep
::= ((
hourFrag
minuteFrag
secondFrag
) |
endOfDayFrag
timezoneFrag
The
timeLexicalRep
production
is equivalent to this
regular expression, once whitespace is
removed:
(([01][0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9](\.[0-9]+)?|(24:00:00(\.0+)?))(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
Note that neither
the
timeLexicalRep
production
nor this regular
expression alone enforce the constraint
on
timeLexicalRep
given above.
The
lexical mapping
for
time
is
timeLexicalMap
; the
canonical mapping
is
timeCanonicalMap
Note:
The
lexical mapping
maps '
00:00:00
' and
24:00:00
' to the same value, namely midnight
hour
= 0 ,
minute
= 0 ,
second
= 0).
3.3.8.3
Facets
The
time
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
time
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
time
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
time
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.9 date
[Definition:]
date
represents top-open intervals of exactly one day in length on the timelines of
dateTime
, beginning on the beginning moment of each
day, up to but not including the beginning
moment of the next day). For non-timezoned values, the top-open
intervals disjointly cover the non-timezoned timeline,
one per day. For timezoned
values, the intervals begin at every minute and therefore overlap.
3.3.9.1 Value Space
date
uses the
date/timeSevenPropertyModel
, with
hour
minute
and
second
required
to be
absent
timezoneOffset
remains
optional
Constraint: Day-of-month Values
The
day
value
must
be
no more than 30 if
month
is one of 4, 6, 9, or 11, no more than 28
if
month
is 2 and
year
is not divisible by 4,
or is divisible by 100 but not by 400,
and no more than 29 if
month
is 2 and
year
is divisible by 400, or by 4 but not by 100.
Note:
See the conformance note in
Partial Implementation of Infinite Datatypes (§5.4)
which applies to the
year
value of this datatype.
Equality and order are as prescribed in
The Seven-property Model (§D.2.1)
Note:
In version 1.0 of this specification,
date
values
did not retain a time zone offset explicitly, but for
offsets
not too far from
zero
their time zone offset could be recovered based on
their value's first moment on the timeline. The
date/timeSevenPropertyModel
retains all time zone offsets.
Some
date
values with
different time zone offsets that were identical in the 1.0 version
of this specification, such as 2000-01-01+13:00
and 1999-12-31−11:00, are in this version
of this specification equal (because they begin
at the same moment on the time line) but are
not identical (because they have and retain different
time zone offsets). This situation will arise for
dates only if one has a far-from-zero time zone offset and
hence in 1.0 its "recoverable time zone offset"
was different from the the time zone offset which is retained
in the
date/timeSevenPropertyModel
used in this version
of this specification.
3.3.9.2 Lexical Mapping
The lexical representations for
date
are "projections" of
those of
dateTime
, as follows:
Lexical Space
[18]
dateLexicalRep
::=
yearFrag
monthFrag
dayFrag
timezoneFrag
Constraint:
Day-of-month Representations
Constraint: Day-of-month Representations
Within a
dateLexicalRep
dayFrag
must not
begin with the digit '
' or be '
29
unless the value to
which it would map would satisfy the value constraint on
day
values
("Constraint: Day-of-month Values") given above.
The
dateLexicalRep
production
is equivalent to this
regular expression:
-?([1-9][0-9]{3,}|0[0-9]{3})-(0[1-9]|1[0-2])-(0[1-9]|[12][0-9]|3[01])(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
Note that neither
the
dateLexicalRep
production
nor this regular
expression alone enforce the constraint
on
dateLexicalRep
given above.
The
lexical mapping
for
date
is
dateLexicalMap
The
canonical mapping
is
dateCanonicalMap
3.3.9.3 Facets
The
date
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
date
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
date
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
date
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.10 gYearMonth
gYearMonth
represents specific whole Gregorian months in specific
Gregorian years.
Note:
Because month/year combinations in one calendar only rarely correspond
to month/year combinations in other calendars, values of this type
are not, in general, convertible to simple values corresponding to month/year
combinations in other calendars. This type should therefore be used
with caution in contexts where conversion to other calendars is desired.
3.3.10.1 Value Space
gYearMonth
uses the
date/timeSevenPropertyModel
, with
day
hour
minute
, and
second
required
to be
absent
timezoneOffset
remains
optional
Note:
See the conformance note in
Partial Implementation of Infinite Datatypes (§5.4)
which applies to the
year
value of this datatype.
Equality and order are as prescribed in
The Seven-property Model (§D.2.1)
3.3.10.2 Lexical
Mapping
The lexical representations for
gYearMonth
are "projections" of
those of
dateTime
, as follows:
Lexical Space
[19]
gYearMonthLexicalRep
::=
yearFrag
monthFrag
timezoneFrag
The
gYearMonthLexicalRep
is equivalent to this regular expression:
-?([1-9][0-9]{3,}|0[0-9]{3})-(0[1-9]|1[0-2])(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
The
lexical mapping
for
gYearMonth
is
gYearMonthLexicalMap
The
canonical mapping
is
gYearMonthCanonicalMap
3.3.10.3
Facets
The
gYearMonth
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
gYearMonth
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
gYearMonth
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
gYearMonth
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.11 gYear
gYear
represents Gregorian calendar years.
Note:
Because years in one calendar only rarely correspond to years
in other calendars, values of this type
are not, in general, convertible to simple values corresponding to years
in other calendars. This type should therefore be used with caution
in contexts where conversion to other calendars is desired.
3.3.11.1 Value Space
gYear
uses the
date/timeSevenPropertyModel
, with
month
day
hour
minute
, and
second
required
to be
absent
timezoneOffset
remains
optional
Note:
See the conformance note in
Partial Implementation of Infinite Datatypes (§5.4)
which applies to the
year
value of this datatype.
Equality and order are as prescribed in
The Seven-property Model (§D.2.1)
3.3.11.2 Lexical
Mapping
The lexical representations for
gYear
are "projections" of
those of
dateTime
, as follows:
Lexical Space
[20]
gYearLexicalRep
::=
yearFrag
timezoneFrag
The
gYearLexicalRep
is equivalent to this regular expression:
-?([1-9][0-9]{3,}|0[0-9]{3})(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
The
lexical mapping
for
gYear
is
gYearLexicalMap
The
canonical mapping
is
gYearCanonicalMap
3.3.11.3
Facets
The
gYear
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
gYear
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
gYear
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
gYear
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.12 gMonthDay
gMonthDay
represents whole calendar
days that recur at the same point in each calendar year, or that occur
in some arbitrary calendar year. (Obviously,
days beyond 28 cannot occur in all Februaries; 29 is nonetheless
permitted.)
This datatype can be used, for example, to record
birthdays; an instance of the datatype could be used to say that
someone's birthday occurs on the 14th of September every year.
Note:
Because day/month combinations in one calendar only rarely correspond
to day/month combinations in other calendars, values of this type do not,
in general, have any straightforward or intuitive representation
in terms of most other calendars. This type should therefore be
used with caution in contexts where conversion to other calendars
is desired.
3.3.12.1 Value Space
gMonthDay
uses the
date/timeSevenPropertyModel
, with
year
hour
minute
, and
second
required
to be
absent
timezoneOffset
remains
optional
Constraint: Day-of-month Values
The
day
value
must
be no more than 30 if
month
is one of 4, 6, 9, or 11, and no more than 29 if
month
is 2.
Equality and order are as prescribed in
The Seven-property Model (§D.2.1)
Note:
In version 1.0 of this specification,
gMonthDay
values
did not retain a time zone offset explicitly, but for time zone offsets not too far from
UTC
their time zone offset could be recovered based on
their value's first moment on the timeline. The
date/timeSevenPropertyModel
retains all time zone offsets.
An example that shows the difference from version 1.0 (see
Lexical
Mapping (§3.3.12.2)
for the notations):
A day is a calendar (or "local time") day
offset from
UTC
by the appropriate interval;
this is now true for all
day
values, including those with time zone offsets outside the range
+12:00 through -11:59 inclusive:
--12-12+13:00 < --12-12+11:00
(just as --12-12+12:00 has always been less than
--12-12+11:00, but in version 1.0
--12-12+13:00 > --12-12+11:00 , since
--12-12+13:00's "recoverable
time zone offset" was −11:00)
3.3.12.2 Lexical
Mapping
The lexical representations for
gMonthDay
are "projections"
of those of
dateTime
, as follows:
Lexical Space
[21]
gMonthDayLexicalRep
::= '
--
monthFrag
dayFrag
timezoneFrag
Constraint:
Day-of-month Representations
Constraint: Day-of-month Representations
Within a
gMonthDayLexicalRep
, a
dayFrag
must not
begin with the digit '
' or be '
29
unless the value to
which it would map would satisfy the value constraint on
day
values
("Constraint: Day-of-month Values") given above.
The
gMonthDayLexicalRep
is equivalent to this regular
expression:
--(0[1-9]|1[0-2])-(0[1-9]|[12][0-9]|3[01])(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
Note that neither
the
gMonthDayLexicalRep
production
nor this regular
expression alone enforce the constraint
on
gMonthDayLexicalRep
given above.
The
lexical mapping
for
gMonthDay
is
gMonthDayLexicalMap
The
canonical mapping
is
gMonthDayCanonicalMap
3.3.12.3
Facets
The
gMonthDay
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
gMonthDay
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
gMonthDay
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
gMonthDay
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.13 gDay
[Definition:]
gDay
represents
whole days within an arbitrary month—days that recur at the same
point in each (Gregorian) month.
This datatype is used to represent a specific day of the month.
To indicate, for example, that an employee gets a paycheck on the 15th of each month. (Obviously, days
beyond 28 cannot occur in
all
months; they are nonetheless permitted, up to 31.)
Note:
Because days in one calendar only rarely
correspond to days in other calendars,
gDay
values do not, in general, have any straightforward or
intuitive representation in terms of most
non-Gregorian
calendars.
gDay
should therefore be used with caution in contexts where conversion to
other calendars is desired.
3.3.13.1 Value Space
gDay
uses the
date/timeSevenPropertyModel
, with
year
month
hour
minute
and
second
required to be
absent
timezoneOffset
remains
optional
and
day
must
be between 1 and 31 inclusive.
Equality and order are as prescribed in
The Seven-property Model (§D.2.1)
. Since
gDay
values (days) are ordered by their first moments, it is possible
for apparent anomalies to appear in the order when
timezoneOffset
values
differ by at least 24
hours. (It is possible for
timezoneOffset
values to differ by up to 28 hours.)
Examples that may appear anomalous (see
Lexical Mapping (§3.3.13.2)
for the notations):
---15 < ---16 , but ---15−13:00 > ---16+13:00
---15−11:00 = ---16+13:00
---15−13:00 <> ---16 ,
because ---15−13:00 > ---16+14:00
and ---15−13:00 < 16−14:00
Note:
Time zone offsets do not cause wrap-around at the end of the month:
the last day of a
given month with a time zone offset of
−13:00 may start after the first
day of the
next
month
with offset +13:00, as
measured on the global timeline,
but nonetheless
---01+13:00 < ---31−13:00 .
3.3.13.2 Lexical Mapping
The lexical representations for
gDay
are
"projections"
of those of
dateTime
, as follows:
Lexical Space
[22]
gDayLexicalRep
::= '
---
dayFrag
timezoneFrag
The
gDayLexicalRep
is equivalent to this regular expression:
---(0[1-9]|[12][0-9]|3[01])(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
The
lexical mapping
for
gDay
is
gDayLexicalMap
The
canonical mapping
is
gDayCanonicalMap
3.3.13.3
Facets
The
gDay
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
gDay
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
gDay
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
gDay
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.14 gMonth
gMonth
represents whole (Gregorian) months
within an arbitrary year—months that recur at the same point in
each year. It might be used, for example, to say what
month annual Thanksgiving celebrations fall in different countries
(--11 in the United States, --10 in Canada, and possibly other months in
other countries).
Note:
Because months in one calendar only rarely correspond
to months in other calendars, values of this type do not,
in general, have any straightforward or intuitive representation
in terms of most other calendars. This type should therefore be
used with caution in contexts where conversion to other calendars
is desired.
3.3.14.1 Value Space
gMonth
uses the
date/timeSevenPropertyModel
, with
year
day
hour
minute
, and
second
required
to be
absent
timezoneOffset
remains
optional
Equality and order are as prescribed in
The Seven-property Model (§D.2.1)
3.3.14.2 Lexical
Mapping
The lexical representations for
gMonth
are "projections" of
those of
dateTime
, as follows:
Lexical Space
[23]
gMonthLexicalRep
::= '
--
monthFrag
timezoneFrag
The
gMonthLexicalRep
is equivalent to this regular expression:
--(0[1-9]|1[0-2])(Z|(\+|-)((0[0-9]|1[0-3]):[0-5][0-9]|14:00))?
The
lexical mapping
for
gMonth
is
gMonthLexicalMap
The
canonical mapping
is
gMonthCanonicalMap
3.3.14.3
Facets
The
gMonth
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
gMonth
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
explicitTimezone
optional
Datatypes derived by
restriction from
gMonth
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
gMonth
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
3.3.15 hexBinary
[Definition:]
hexBinary
represents arbitrary hex-encoded binary data.
3.3.15.1 Value Space
The
value space
of
hexBinary
is the set of
finite-length sequences of zero or more
binary octets. The
length of a value is the number of octets.
3.3.15.2 Lexical Mapping
hexBinary
's
lexical space
consists of strings of hex (hexadecimal) digits, two consecutive digits
representing each octet in the corresponding value (treating the octet
as the binary representation of a number between 0 and 255). For
example, '
0FB7
' is a
lexical representation
of the
two-octet value 00001111 10110111.
More formally, the
lexical space
of
hexBinary
is the set of literals matching the
hexBinary
production.
Lexical space of hexBinary
[24]
hexDigit
::= [
0-9a-fA-F
[25]
hexOctet
::=
hexDigit
hexDigit
[26]
hexBinary
::=
hexOctet
The set recognized by
hexBinary
is the same as that recognized by the regular
expression '
([0-9a-fA-F]{2})*
'.
The
lexical mapping
of
hexBinary
is
hexBinaryMap
The
canonical mapping
of
hexBinary
is given formally in
hexBinaryCanonical
3.3.15.3
Facets
The
hexBinary
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
hexBinary
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
hexBinary
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.3.16 base64Binary
[Definition:]
base64Binary
represents arbitrary
Base64-encoded binary
data.
For
base64Binary
data the entire binary stream is encoded
using the Base64 Encoding
defined in
[RFC 3548]
, which is derived from the encoding
described in
[RFC 2045]
3.3.16.1 Value Space
The
value space
of
base64Binary
is the set of finite-length sequences of
zero or more
binary octets. The
length of a value is the number of octets.
3.3.16.2 Lexical
Mapping
The
lexical representations
of
base64Binary
values are limited to the 65 characters of the Base64 Alphabet defined in
[RFC 3548]
i.e.,
a-z
A-Z
0-9
, the plus sign (+), the forward slash (/) and the
equal sign (=), together with
the space character
(#x20). No other characters are allowed.
For compatibility with older mail gateways,
[RFC 2045]
suggests that Base64 data should have lines limited to at most 76
characters in length. This line-length limitation is not
required by
[RFC 3548]
and is not mandated in the
lexical representations
of
base64Binary
data. It
must not
be enforced by XML Schema processors.
The
lexical space
of
base64Binary
is the
set of literals which
match
the
base64Binary
production.
Lexical space of base64Binary
[27]
Base64Binary
::= (
B64quad
B64final
)?
[28]
B64quad
::= (
B64
B64
B64
B64
/*
B64quad
represents three octets of binary data.
*/
[29]
B64final
::=
B64finalquad
Padded16
Padded8
[30]
B64finalquad
::= (
B64
B64
B64
B64char
/*
B64finalquad
represents three octets
of binary data without trailing space.
*/
[31]
Padded16
::=
B64
B64
B16
/*
Padded16
represents a two-octet
at the end of the data.
*/
[32]
Padded8
::=
B64
B04
' #x20? '
/*
Padded8
represents a single octet at the end of the data.
*/
[33]
B64
::=
B64char
#x20?
[34]
B64char
::= [A-Za-z0-9+/]
[35]
B16
::=
B16char
#x20?
[36]
B16char
::= [AEIMQUYcgkosw048]
/*
Base64 characters whose bit-string value ends in '00'
*/
[37]
B04
::=
B04char
#x20?
[38]
B04char
::= [AQgw]
/*
Base64 characters whose bit-string value ends in
'0000'
*/
The
Base64Binary
production is equivalent
to the following regular expression.
((([A-Za-z0-9+/] ?){4})*(([A-Za-z0-9+/] ?){3}[A-Za-z0-9+/]|([A-Za-z0-9+/] ?){2}[AEIMQUYcgkosw048] ?=|[A-Za-z0-9+/] ?[AQgw] ?= ?=))?
Note that each '
' except the last is preceded by a
single space character.
Note that this grammar requires the number of non-whitespace
characters in the
lexical representation
to be a multiple of four, and
for equals signs to appear only at the end of the
lexical representation
literals
which do not meet these constraints
are not legal
lexical representations
of
base64Binary
The
lexical mapping
for
base64Binary
is as given in
[RFC 2045]
and
[RFC 3548]
Note:
The above definition of the
lexical space
is more restrictive than
that given in
[RFC 2045]
as regards whitespace —
and less restrictive than
[RFC 3548]
This is
not an issue in practice. Any string compatible with
either
RFC can occur in an element or attribute
validated by this type, because the
whiteSpace
facet of this type is fixed to
collapse
, which means that all
leading and trailing whitespace will be stripped, and all internal
whitespace collapsed to single space characters,
before
the above grammar is enforced. The
possibility of ignoring whitespace in Base64 data is foreseen in
clause 2.3 of
[RFC 3548]
, but for the reasons given there
this specification does not allow implementations to ignore
non-whitespace characters which are not in the Base64
Alphabet.
The canonical
lexical representation
of a
base64Binary
data value is the Base64 encoding of the value which matches the
Canonical-base64Binary production in the following grammar:
Canonical representation of base64Binary
[39]
Canonical-base64Binary
::=
CanonicalQuad
CanonicalPadded
[40]
CanonicalQuad
::=
B64char
B64char
B64char
B64char
[41]
CanonicalPadded
::=
B64char
B64char
B16char
B64char
B04char
==
That is, the
canonical representation
of a
base64Binary
value is the
lexical representation
which maps to that value and contains no whitespace. The
canonical mapping
for
base64Binary
is
thus the encoding algorithm for Base64 data given in
[RFC 2045]
and
[RFC 3548]
, with the proviso that no
characters except those in the Base64 Alphabet are to be written
out.
Note:
For some values the
canonical representation
defined above does
not conform to
[RFC 2045]
, which requires breaking with
linefeeds at appropriate intervals. It
does conform with
[RFC 3548]
The length of a
base64Binary
value may be calculated from the
lexical representation
by
removing whitespace and padding characters and performing the
calculation shown in the pseudo-code below:
lex2 := killwhitespace(lexform)
-- remove whitespace characters
lex3 := strip_equals(lex2)
-- strip padding characters at end
length := floor (length(lex3) * 3 / 4)
-- calculate length
Note on encoding:
[RFC 2045]
and
[RFC 3548]
explicitly
reference US-ASCII encoding. However,
decoding of
base64Binary
data in an XML entity is to be performed on the
Unicode characters obtained after character encoding processing as specified by
[XML]
3.3.16.3
Facets
The
base64Binary
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
base64Binary
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
base64Binary
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.3.17 anyURI
[Definition:]
anyURI
represents an
Internationalized Resource Identifier Reference
(IRI). An
anyURI
value can be absolute or relative, and may
have an optional fragment identifier (i.e., it may be
an
IRI Reference). This type should be used
when
the value fulfills the role of
an IRI,
as defined in
[RFC 3987]
or its successor(s) in the IETF
Standards Track.
Note:
IRIs may be used to locate resources
or simply to identify them. In the case where they are used to locate
resources using a URI, applications should use
the mapping from
anyURI
values to URIs given
by the
reference escaping procedure defined in
[LEIRI]
and in
Section
3.1
Mapping
of IRIs to URIs
of
[RFC 3987]
or its successor(s) in the IETF Standards Track.
This means that a wide range of internationalized resource identifiers
can be specified when an
anyURI
is called for, and still be understood as URIs per
[RFC 3986]
and its successor(s).
3.3.17.1 Value Space
The value space of
anyURI
is the set of finite-length
sequences of zero or more
character
s (as defined in
[XML]
) that
match
the
Char
production from
[XML]
3.3.17.2 Lexical
Mapping
The
lexical space
of
anyURI
is the set of finite-length
sequences of zero or more
character
s (as defined in
[XML]
) that
match
the
Char
production from
[XML]
Note:
For an
anyURI
value to be
usable in practice as an IRI, the result of applying to it
the algorithm defined in Section 3.1 of
[RFC 3987]
should
be a string which is a legal URI according
to
[RFC 3986]
. (This is true at the time this document is published;
if in the future
[RFC 3987]
and
[RFC 3986]
are replaced by other specifications
in the IETF Standards Track, the relevant constraints will be those
imposed by those successor specifications.)
Each URI scheme imposes specialized syntax rules
for URIs in that scheme, including restrictions on the syntax of
allowed fragment identifiers. Because it is impractical for processors
to check that a value is a context-appropriate URI reference,
neither the syntactic constraints defined by the definitions of individual
schemes nor the generic syntactic constraints defined by
[RFC 3987]
and
[RFC 3986]
and their
successors are part of this datatype as defined here.
Applications which depend on
anyURI
values
being legal according to the rules of
the relevant specifications
should make arrangements to check values against the appropriate
definitions of IRI, URI, and specific schemes.
Note:
Spaces are, in principle, allowed in the
lexical space
of
anyURI
however, their use is highly discouraged
(unless they are encoded by '
%20
').
The
lexical mapping
for
anyURI
is
the identity mapping.
Note:
The definitions of URI in the current
IETF specifications define certain URIs as equivalent to each other.
Those equivalences are not part of this datatype as defined here:
if two "equivalent" URIs or IRIs are different character
sequences, they map to different values in this datatype.
3.3.17.3
Facets
The
anyURI
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
anyURI
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
anyURI
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.3.18 QName
[Definition:]
QName
represents
XML qualified
names
The
value space
of
QName
is the set of
tuples {
namespace name
local part
},
where
namespace name
is an
anyURI
and
local part
is
an
NCName
The
lexical space
of
QName
is the set
of strings that
match
the
QName
production of
[Namespaces in XML]
It is
implementation-defined
whether an
implementation of this specification supports the
QName
production from
[Namespaces in XML]
, or that from
[Namespaces in XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
The mapping from lexical space to value space for a particular
QName
literal
depends on the namespace bindings in scope where the literal occurs.
When
QName
appear in an XML context, the bindings to be used in
the
lexical mapping
are those in the
[in-scope namespaces]
property of the
relevant element.
When this datatype is used in a non-XML host language,
the host language
must
specify what namespace bindings
are to be used.
The host language, whether XML-based or otherwise,
may
specify whether
unqualified names are bound to the default namespace (if any)
or not; the host language may also place this under user control.
If the host language does not specify otherwise,
unqualified names are bound to the default namespace.
Note:
The default treatment of
unqualified names parallels that specified in
[Namespaces in XML]
for element names (as opposed to that specified
for attribute names).
Note:
The mapping between
literals
in the
lexical space
and
values in the
value space
of
QName
depends on the set of
namespace declarations
in scope for the context
in which
QName
is used.
Because the lexical representations available for
any value of type
QName
vary with context, no
canonical representation
is defined for
QName
in this specification.
3.3.18.1
Facets
The
QName
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
QName
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
QName
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.3.19 NOTATION
[Definition:]
NOTATION
represents the
NOTATION
attribute
type from
[XML]
The
value space
of
NOTATION
is the set of
QName
of notations declared in the current schema.
The
lexical space
of
NOTATION
is the set
of all names of
notations
declared in the current schema (in the form of
QName
s).
Note:
Because its
value space
depends on the notion of a
"current schema", as instantiated for example
by
[XSD 1.1 Part 1: Structures]
, the
NOTATION
datatype is
unsuitable for use in other contexts which lack the notion of a
current schema.
The lexical mapping rules for
NOTATION
are as given for
QName
in
QName (§3.3.18)
Schema Component Constraint: enumeration facet value required for NOTATION
It is (with one exception) an
error
for
NOTATION
to be used
directly to validate a literal as described in
Datatype Valid (§4.1.4)
only datatypes
derived
from
NOTATION
by specifying
a value for
enumeration
can be used to validate literals.
The exception is that in the
derivation
of a new type the
literals
used to enumerate the allowed values
may
be (and in
the context of [XSD 1.1 Part 1: Structures] will be)
validated directly against
NOTATION
; this amounts to
verifying that the value is a
QName
and that the
QName
is the
name of a
NOTATION
declared in the current schema.
For compatibility (see
Terminology (§1.6)
NOTATION
should be used only on attributes
and should only be used in schemas with no
target namespace.
Note:
Because the lexical representations available for any given value
of
NOTATION
vary with context, this specification defines
no
canonical representation
for
NOTATION
values.
3.3.19.1
Facets
The
NOTATION
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
Datatypes derived by
restriction from
NOTATION
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
NOTATION
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
The use of
length
minLength
and
maxLength
on
NOTATION
or
datatypes
derived
from
NOTATION
is
deprecated. Future versions of this specification may
remove these facets for this datatype.
3.4 Other Built-in Datatypes
3.4.1
normalizedString
3.4.1.1
Facets
3.4.1.2
Derived datatypes
3.4.2
token
3.4.2.1
Facets
3.4.2.2
Derived datatypes
3.4.3
language
3.4.3.1
Facets
3.4.4
NMTOKEN
3.4.4.1
Facets
3.4.4.2
Related datatypes
3.4.5
NMTOKENS
3.4.5.1
Facets
3.4.6
Name
3.4.6.1
Facets
3.4.6.2
Derived datatypes
3.4.7
NCName
3.4.7.1
Facets
3.4.7.2
Derived datatypes
3.4.8
ID
3.4.8.1
Facets
3.4.9
IDREF
3.4.9.1
Facets
3.4.9.2
Related datatypes
3.4.10
IDREFS
3.4.10.1
Facets
3.4.11
ENTITY
3.4.11.1
Facets
3.4.11.2
Related datatypes
3.4.12
ENTITIES
3.4.12.1
Facets
3.4.13
integer
3.4.13.1
Lexical representation
3.4.13.2
Canonical representation
3.4.13.3
Facets
3.4.13.4
Derived datatypes
3.4.14
nonPositiveInteger
3.4.14.1
Lexical representation
3.4.14.2
Canonical representation
3.4.14.3
Facets
3.4.14.4
Derived datatypes
3.4.15
negativeInteger
3.4.15.1
Lexical representation
3.4.15.2
Canonical representation
3.4.15.3
Facets
3.4.16
long
3.4.16.1
Lexical Representation
3.4.16.2
Canonical Representation
3.4.16.3
Facets
3.4.16.4
Derived datatypes
3.4.17
int
3.4.17.1
Lexical Representation
3.4.17.2
Canonical representation
3.4.17.3
Facets
3.4.17.4
Derived datatypes
3.4.18
short
3.4.18.1
Lexical representation
3.4.18.2
Canonical representation
3.4.18.3
Facets
3.4.18.4
Derived datatypes
3.4.19
byte
3.4.19.1
Lexical representation
3.4.19.2
Canonical representation
3.4.19.3
Facets
3.4.20
nonNegativeInteger
3.4.20.1
Lexical representation
3.4.20.2
Canonical representation
3.4.20.3
Facets
3.4.20.4
Derived datatypes
3.4.21
unsignedLong
3.4.21.1
Lexical representation
3.4.21.2
Canonical representation
3.4.21.3
Facets
3.4.21.4
Derived datatypes
3.4.22
unsignedInt
3.4.22.1
Lexical representation
3.4.22.2
Canonical representation
3.4.22.3
Facets
3.4.22.4
Derived datatypes
3.4.23
unsignedShort
3.4.23.1
Lexical representation
3.4.23.2
Canonical representation
3.4.23.3
Facets
3.4.23.4
Derived datatypes
3.4.24
unsignedByte
3.4.24.1
Lexical representation
3.4.24.2
Canonical representation
3.4.24.3
Facets
3.4.25
positiveInteger
3.4.25.1
Lexical representation
3.4.25.2
Canonical representation
3.4.25.3
Facets
3.4.26
yearMonthDuration
3.4.26.1
The Lexical Mapping
3.4.26.2
Facets
3.4.27
dayTimeDuration
3.4.27.1
The Lexical Space
3.4.27.2
Facets
3.4.28
dateTimeStamp
3.4.28.1
The Lexical Space
3.4.28.2
Facets
This section gives conceptual definitions for all
built-in
ordinary
datatypes defined by this specification. The XML representation used to define
ordinary
datatypes (whether
built-in
or
user-defined
) is
given in
XML Representation of Simple Type Definition Schema Components (§4.1.2)
and the complete
definitions of the
built-in
ordinary
datatypes are provided in the appendix
Schema for Schema Documents (Datatypes)
(normative) (§A)
3.4.1 normalizedString
[Definition:]
normalizedString
represents white space normalized strings.
The
value space
of
normalizedString
is the
set of strings that do not
contain the carriage return (#xD), line feed (#xA) nor tab (#x9) characters.
The
lexical space
of
normalizedString
is the
set of strings that do not
contain the carriage return (#xD),
line feed (#xA)
nor tab (#x9) characters.
The
base type
of
normalizedString
is
string
3.4.1.1
Facets
The
normalizedString
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
whiteSpace
replace
Datatypes derived by
restriction from
normalizedString
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
normalizedString
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.1.2 Derived datatypes
The following
built-in
datatype is
derived
from
normalizedString
token
3.4.2 token
[Definition:]
token
represents tokenized strings.
The
value space
of
token
is the
set of strings that do not
contain the
carriage return (#xD),
line feed (#xA) nor tab (#x9) characters, that have no
leading or trailing spaces (#x20) and that have no internal sequences
of two or more spaces.
The
lexical space
of
token
is the
set of strings that do not contain the
carriage return (#xD),
line feed (#xA) nor tab (#x9) characters, that have no
leading or trailing spaces (#x20) and that have no internal sequences
of two or more spaces.
The
base type
of
token
is
normalizedString
3.4.2.1
Facets
The
token
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
whiteSpace
collapse
Datatypes derived by
restriction from
token
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
pattern
enumeration
assertions
The
token
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.2.2 Derived datatypes
The following
built-in
datatypes are
derived
from
token
language
NMTOKEN
Name
3.4.3 language
[Definition:]
language
represents formal
natural language identifiers,
as defined
by
[BCP 47]
(currently represented by
[RFC 4646]
and
[RFC 4647]
or its successor(s).
The
value space
and
lexical space
of
language
are
the set of all strings that conform to the pattern
[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*
This is the set of strings
accepted by the grammar given in
[RFC 3066]
which is now obsolete; the current specification of language
codes is more restrictive. The
base type
of
language
is
token
Note:
The regular expression above provides the only normative
constraint on the lexical and value spaces of this type. The
additional constraints imposed on language identifiers by
[BCP 47]
and its successor(s), and in particular their requirement that language
codes be registered with IANA or ISO if not given in ISO 639, are
not part of this datatype as defined here.
Note:
[BCP 47]
specifies
that language codes "are to be treated as case insensitive; there
exist conventions for capitalization of some of
the
subtags, but these MUST NOT be taken
to carry meaning."
Since the
language
datatype is
derived from
string
, it inherits from
string
a one-to-one mapping from lexical
representations to values. The literals '
MN
' and
mn
' (for
Mongolian)
therefore correspond to distinct values and
have distinct canonical forms. Users of this specification should be
aware of this fact, the consequence of which is that the
case-insensitive treatment of language values prescribed by
[BCP 47]
does not follow from the definition of
this datatype given here; applications which require
case-insensitivity
should make appropriate adjustments.
Note:
The empty string is not a member of the
value space
of
language
. Some constructs which normally
take language codes as their values, however, also allow the
empty string. The attribute
xml:lang
defined by
[XML]
is one example; there, the empty string
overrides a value which would otherwise be inherited, but
without specifying a new value.
One way to define the desired set of possible values is
illustrated by the schema document for the XML namespace
at
, which defines the
attribute
xml:lang
as having a type which is a union
of
language
and an anonymous type whose
only value is the empty string:
See RFC 3066 at http://www.ietf.org/rfc/rfc3066.txt
and the IANA registry at
further information.
The union allows for the 'un-declaration' of xml:lang with
the empty string.
3.4.3.1
Facets
The
language
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[a-zA-Z]{1,8}(-[a-zA-Z0-9]{1,8})*
whiteSpace
collapse
Datatypes derived by
restriction from
language
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
enumeration
assertions
The
language
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.4 NMTOKEN
[Definition:]
NMTOKEN
represents
the
NMTOKEN attribute type
from
[XML]
. The
value space
of
NMTOKEN
is the set of tokens that
match
the
Nmtoken
production in
[XML]
. The
lexical space
of
NMTOKEN
is the set of strings that
match
the
Nmtoken
production in
[XML]
. The
base type
of
NMTOKEN
is
token
It is
implementation-defined
whether an
implementation of this specification supports the
NMTOKEN
production from
[XML]
, or that from
[XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
For compatibility (see
Terminology (§1.6)
NMTOKEN
should be used only on attributes.
3.4.4.1
Facets
The
NMTOKEN
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
\c+
whiteSpace
collapse
Datatypes derived by
restriction from
NMTOKEN
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
enumeration
assertions
The
NMTOKEN
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.4.2 Related datatypes
The following
built-in
datatype is
constructed
from
NMTOKEN
NMTOKENS
3.4.5 NMTOKENS
[Definition:]
NMTOKENS
represents the
NMTOKENS attribute
type
from
[XML]
. The
value space
of
NMTOKENS
is the set of finite, non-zero-length sequences of
NMTOKEN
s. The
lexical space
of
NMTOKENS
is the set of space-separated lists of tokens,
of which each token is in the
lexical space
of
NMTOKEN
. The
item type
of
NMTOKENS
is
NMTOKEN
NMTOKENS
is derived
from
anySimpleType
in two steps: an anonymous list type
is defined, whose
item type
is
NMTOKEN
; this is
the
base type
of
NMTOKENS
, which restricts
its value space to lists with at least one item.
For compatibility (see
Terminology (§1.6)
NMTOKENS
should be used only on attributes.
3.4.5.1
Facets
The
NMTOKENS
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
minLength
whiteSpace
collapse
Datatypes derived by
restriction from
NMTOKENS
may
also
specify values for the
following
constraining facets
length
maxLength
enumeration
pattern
assertions
The
NMTOKENS
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.6 Name
[Definition:]
Name
represents
XML Names
The
value space
of
Name
is
the set of all strings which
match
the
Name
production of
[XML]
. The
lexical space
of
Name
is the set of all strings which
match
the
Name
production of
[XML]
. The
base type
of
Name
is
token
It is
implementation-defined
whether an
implementation of this specification supports the
Name
production from
[XML]
, or that from
[XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
3.4.6.1
Facets
The
Name
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
\i\c*
whiteSpace
collapse
Datatypes derived by
restriction from
Name
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
enumeration
assertions
The
Name
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.6.2 Derived datatypes
The following
built-in
datatype is
derived
from
Name
NCName
3.4.7 NCName
[Definition:]
NCName
represents XML
"non-colonized" Names. The
value space
of
NCName
is the set of all strings which
match
the
NCName
production of
[Namespaces in XML]
. The
lexical space
of
NCName
is the set of all strings which
match
the
NCName
production of
[Namespaces in XML]
. The
base type
of
NCName
is
Name
It is
implementation-defined
whether an
implementation of this specification supports the
NCName
production from
[Namespaces in XML]
, or that from
[Namespaces in XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
3.4.7.1
Facets
The
NCName
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
\i\c* ∩ [\i-[:]][\c-[:]]*
whiteSpace
collapse
Datatypes derived by
restriction from
NCName
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
enumeration
assertions
The
NCName
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.7.2 Derived datatypes
The following
built-in
datatypes are
derived
from
NCName
ID
IDREF
ENTITY
3.4.8 ID
[Definition:]
ID
represents the
ID attribute type
from
[XML]
. The
value space
of
ID
is the set of all strings that
match
the
NCName
production in
[Namespaces in XML]
. The
lexical space
of
ID
is the set of all
strings that
match
the
NCName
production in
[Namespaces in XML]
The
base type
of
ID
is
NCName
Note:
It is
implementation-defined
whether an
implementation of this specification supports
the
NCName
production from
[Namespaces in XML]
, or that from
[Namespaces in XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
For compatibility (see
Terminology (§1.6)
),
ID
should be used only on attributes.
Note:
Uniqueness of items validated as
ID
is not
part of this datatype as defined here.
When this specification is used in conjunction with
[XSD 1.1 Part 1: Structures]
, uniqueness is enforced at a
different level, not as part of datatype validity;
see
Validation Rule: Validation Root Valid (ID/IDREF)
in
[XSD 1.1 Part 1: Structures]
3.4.8.1
Facets
The
ID
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
\i\c* ∩ [\i-[:]][\c-[:]]*
whiteSpace
collapse
Datatypes derived by
restriction from
ID
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
enumeration
assertions
The
ID
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.9 IDREF
[Definition:]
IDREF
represents the
IDREF attribute type
from
[XML]
. The
value space
of
IDREF
is the set of all strings that
match
the
NCName
production in
[Namespaces in XML]
. The
lexical space
of
IDREF
is the set of
strings that
match
the
NCName
production in
[Namespaces in XML]
The
base type
of
IDREF
is
NCName
Note:
It is
implementation-defined
whether an
implementation of this specification supports
the
NCName
production from
[Namespaces in XML]
, or that from
[Namespaces in XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
For compatibility (see
Terminology (§1.6)
) this datatype
should be used only on attributes.
Note:
Existence of referents for items validated as
IDREF
is not part of this
datatype as defined here.
When this specification is used in conjunction with
[XSD 1.1 Part 1: Structures]
, referential integrity is enforced at a
different level, not as part of datatype validity;
see
Validation Rule: Validation
Root Valid (ID/IDREF)
in
[XSD 1.1 Part 1: Structures]
3.4.9.1
Facets
The
IDREF
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
\i\c* ∩ [\i-[:]][\c-[:]]*
whiteSpace
collapse
Datatypes derived by
restriction from
IDREF
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
enumeration
assertions
The
IDREF
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.9.2 Related datatypes
The following
built-in
datatype is
constructed
from
IDREF
IDREFS
3.4.10 IDREFS
[Definition:]
IDREFS
represents the
IDREFS attribute type
from
[XML]
. The
value space
of
IDREFS
is the set of finite, non-zero-length sequences of
IDREF
s.
The
lexical space
of
IDREFS
is the
set of space-separated lists of tokens, of which each token is in the
lexical space
of
IDREF
The
item type
of
IDREFS
is
IDREF
IDREFS
is derived
from
anySimpleType
in two steps: an anonymous list type
is defined, whose
item type
is
IDREF
; this is
the
base type
of
IDREFS
, which restricts
its value space to lists with at least one item.
For compatibility (see
Terminology (§1.6)
IDREFS
should be used only on attributes.
Note:
Existence of referents for items validated as
IDREFS
is not
part of this datatype as defined here.
When this specification is used in conjunction with
[XSD 1.1 Part 1: Structures]
, referential integrity is enforced at a
different level, not as part of datatype validity;
see
Validation Rule:
Validation Root Valid (ID/IDREF)
in
[XSD 1.1 Part 1: Structures]
3.4.10.1
Facets
The
IDREFS
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
minLength
whiteSpace
collapse
Datatypes derived by
restriction from
IDREFS
may
also
specify values for the
following
constraining facets
length
maxLength
enumeration
pattern
assertions
The
IDREFS
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.11 ENTITY
[Definition:]
ENTITY
represents the
ENTITY
attribute type from
[XML]
. The
value space
of
ENTITY
is the set of all strings that
match
the
NCName
production in
[Namespaces in XML]
and have been declared as an
unparsed entity
in
document type definition
The
lexical space
of
ENTITY
is the set
of all strings that
match
the
NCName
production in
[Namespaces in XML]
The
base type
of
ENTITY
is
NCName
Note:
It is
implementation-defined
whether an
implementation of this specification supports
the
NCName
production from
[Namespaces in XML]
, or that from
[Namespaces in XML 1.0]
, or both. See
Dependencies on Other Specifications (§1.3)
Note:
The
value space
of
ENTITY
is scoped to a specific instance document.
For compatibility (see
Terminology (§1.6)
ENTITY
should be used only on attributes.
3.4.11.1
Facets
The
ENTITY
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
\i\c* ∩ [\i-[:]][\c-[:]]*
whiteSpace
collapse
Datatypes derived by
restriction from
ENTITY
may
also
specify values for the
following
constraining facets
length
minLength
maxLength
enumeration
assertions
The
ENTITY
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.11.2 Related datatypes
The following
built-in
datatype is
constructed
from
ENTITY
ENTITIES
3.4.12 ENTITIES
[Definition:]
ENTITIES
represents the
ENTITIES attribute
type
from
[XML]
. The
value space
of
ENTITIES
is the set of finite, non-zero-length sequences of
ENTITY
values that have been declared as
unparsed entities
in a
document type definition
The
lexical space
of
ENTITIES
is the
set of space-separated lists of tokens, of which each token is in the
lexical space
of
ENTITY
The
item type
of
ENTITIES
is
ENTITY
ENTITIES
is derived
from
anySimpleType
in two steps: an anonymous list type
is defined, whose
item type
is
ENTITY
; this is
the
base type
of
ENTITIES
, which restricts
its value space to lists with at least one item.
Note:
The
value space
of
ENTITIES
is scoped to a specific instance document.
For compatibility (see
Terminology (§1.6)
ENTITIES
should be used only on attributes.
3.4.12.1
Facets
The
ENTITIES
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
minLength
whiteSpace
collapse
Datatypes derived by
restriction from
ENTITIES
may
also
specify values for the
following
constraining facets
length
maxLength
enumeration
pattern
assertions
The
ENTITIES
datatype
has the following values for its
fundamental facets
ordered
false
bounded
false
cardinality
countably infinite
numeric
false
3.4.13 integer
[Definition:]
integer
is
derived
from
decimal
by fixing the
value of
fractionDigits
to be 0 and
disallowing the trailing decimal point.
This results in the standard
mathematical concept of the integer numbers. The
value space
of
integer
is the infinite
set {...,-2,-1,0,1,2,...}. The
base type
of
integer
is
decimal
3.4.13.1 Lexical representation
integer
has a lexical representation consisting of a finite-length sequence
of one or more
decimal digits (#x30-#x39) with an optional leading sign. If the sign is omitted,
"+" is assumed. For example: -1, 0, 12678967543233, +100000.
3.4.13.2 Canonical representation
The
canonical representation
for
integer
is defined by prohibiting certain options from the
Lexical representation (§3.4.13.1)
Specifically, the preceding optional "+" sign is prohibited
and leading zeroes are prohibited.
3.4.13.3 Facets
The
integer
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
integer
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
Datatypes derived by
restriction from
integer
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
integer
datatype
has the following values for its
fundamental facets
ordered
total
bounded
false
cardinality
countably infinite
numeric
true
3.4.13.4 Derived datatypes
The following
built-in
datatypes are
derived
from
integer
nonPositiveInteger
long
nonNegativeInteger
3.4.14 nonPositiveInteger
[Definition:]
nonPositiveInteger
is
derived
from
integer
by setting the value of
maxInclusive
to be 0. This results in the
standard mathematical concept of the non-positive integers.
The
value space
of
nonPositiveInteger
is the infinite set {...,-2,-1,0}. The
base type
of
nonPositiveInteger
is
integer
3.4.14.1 Lexical representation
nonPositiveInteger
has a lexical representation consisting of
an optional preceding sign
followed by a non-empty
finite-length sequence of decimal digits (#x30-#x39).
The sign may be "+" or may be omitted only for
lexical forms denoting zero; in all other lexical forms, the negative
sign ('
')
must
be present.
For example: -1, 0, -12678967543233, -100000.
3.4.14.2 Canonical representation
The
canonical representation
for
nonPositiveInteger
is defined by prohibiting certain options from the
Lexical representation (§3.4.14.1)
In the canonical form for zero, the sign
must
be
omitted. Leading zeroes are prohibited.
3.4.14.3
Facets
The
nonPositiveInteger
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
nonPositiveInteger
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
Datatypes derived by
restriction from
nonPositiveInteger
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minInclusive
minExclusive
assertions
The
nonPositiveInteger
datatype
has the following values for its
fundamental facets
ordered
total
bounded
false
cardinality
countably infinite
numeric
true
3.4.14.4 Derived datatypes
The following
built-in
datatype is
derived
from
nonPositiveInteger
negativeInteger
3.4.15 negativeInteger
[Definition:]
negativeInteger
is
derived
from
nonPositiveInteger
by setting the value of
maxInclusive
to be -1. This results in the
standard mathematical concept of the negative integers. The
value space
of
negativeInteger
is the infinite set {...,-2,-1}. The
base type
of
negativeInteger
is
nonPositiveInteger
3.4.15.1 Lexical representation
negativeInteger
has a lexical representation consisting
of a negative sign ('
') followed by a non-empty finite-length sequence of
decimal digits (#x30-#x39),
at least one of which
must
be a digit other than '
'.
For example: -1, -12678967543233,
-100000.
3.4.15.2 Canonical representation
The
canonical representation
for
negativeInteger
is defined by prohibiting certain options from the
Lexical representation (§3.4.15.1)
Specifically, leading zeroes are prohibited.
3.4.15.3
Facets
The
negativeInteger
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
negativeInteger
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
-1
Datatypes derived by
restriction from
negativeInteger
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minInclusive
minExclusive
assertions
The
negativeInteger
datatype
has the following values for its
fundamental facets
ordered
total
bounded
false
cardinality
countably infinite
numeric
true
3.4.16 long
[Definition:]
long
is
derived
from
integer
by setting the
value of
maxInclusive
to be 9223372036854775807
and
minInclusive
to be -9223372036854775808.
The
base type
of
long
is
integer
3.4.16.1 Lexical Representation
long
has a lexical representation consisting
of an optional sign followed by a non-empty finite-length
sequence of decimal digits (#x30-#x39). If
the sign is omitted, "+" is assumed.
For example: -1, 0,
12678967543233, +100000.
3.4.16.2 Canonical Representation
The
canonical representation
for
long
is defined by prohibiting certain options from the
Lexical Representation (§3.4.16.1)
. Specifically, the
the optional "+" sign is prohibited and leading zeroes are prohibited.
3.4.16.3
Facets
The
long
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
long
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
9223372036854775807
minInclusive
-9223372036854775808
Datatypes derived by
restriction from
long
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
long
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.16.4 Derived datatypes
The following
built-in
datatype is
derived
from
long
int
3.4.17 int
[Definition:]
int
is
derived
from
long
by setting the
value of
maxInclusive
to be 2147483647 and
minInclusive
to be -2147483648. The
base type
of
int
is
long
3.4.17.1 Lexical Representation
int
has a lexical representation consisting
of an optional sign followed by a non-empty finite-length
sequence of decimal digits (#x30-#x39). If the sign is omitted, "+" is assumed.
For example: -1, 0, 126789675, +100000.
3.4.17.2 Canonical representation
The
canonical representation
for
int
is defined by prohibiting certain options from the
Lexical Representation (§3.4.17.1)
. Specifically, the
the optional "+" sign is prohibited and leading zeroes are prohibited.
3.4.17.3
Facets
The
int
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
int
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
2147483647
minInclusive
-2147483648
Datatypes derived by
restriction from
int
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
int
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.17.4 Derived datatypes
The following
built-in
datatype is
derived
from
int
short
3.4.18 short
[Definition:]
short
is
derived
from
int
by setting the
value of
maxInclusive
to be 32767 and
minInclusive
to be -32768. The
base type
of
short
is
int
3.4.18.1 Lexical representation
short
has a lexical representation consisting
of an optional sign followed by a non-empty finite-length sequence of decimal
digits (#x30-#x39). If the sign is omitted, "+" is assumed.
For example: -1, 0, 12678, +10000.
3.4.18.2 Canonical representation
The
canonical representation
for
short
is defined by prohibiting certain options from the
Lexical representation (§3.4.18.1)
. Specifically, the
the optional "+" sign is prohibited and leading zeroes are prohibited.
3.4.18.3
Facets
The
short
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
short
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
32767
minInclusive
-32768
Datatypes derived by
restriction from
short
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
short
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.18.4 Derived datatypes
The following
built-in
datatype is
derived
from
short
byte
3.4.19 byte
[Definition:]
byte
is
derived
from
short
by setting the value of
maxInclusive
to be 127
and
minInclusive
to be -128.
The
base type
of
byte
is
short
3.4.19.1 Lexical representation
byte
has a lexical representation consisting
of an optional sign followed by a non-empty finite-length
sequence of decimal digits (#x30-#x39). If the sign is omitted, "+" is assumed.
For example: -1, 0, 126, +100.
3.4.19.2 Canonical representation
The
canonical representation
for
byte
is defined by prohibiting certain options from the
Lexical representation (§3.4.19.1)
. Specifically, the
the optional "+" sign is prohibited and leading zeroes are prohibited.
3.4.19.3
Facets
The
byte
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
byte
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
127
minInclusive
-128
Datatypes derived by
restriction from
byte
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
byte
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.20 nonNegativeInteger
[Definition:]
nonNegativeInteger
is
derived
from
integer
by setting the value of
minInclusive
to be 0. This results in the
standard mathematical concept of the non-negative integers. The
value space
of
nonNegativeInteger
is the infinite set {0,1,2,...}. The
base type
of
nonNegativeInteger
is
integer
3.4.20.1 Lexical representation
nonNegativeInteger
has a lexical representation consisting of
an optional sign followed by a non-empty finite-length
sequence of decimal digits (#x30-#x39). If the sign is omitted,
the positive sign ('
') is assumed.
If the sign is present, it
must
be "+" except for lexical forms
denoting zero, which may be preceded by a positive ('
') or a negative ('
') sign.
For example:
1, 0, 12678967543233, +100000.
3.4.20.2 Canonical representation
The
canonical representation
for
nonNegativeInteger
is defined by prohibiting certain options from the
Lexical representation (§3.4.20.1)
. Specifically, the
the optional "+" sign is prohibited and leading zeroes are prohibited.
3.4.20.3
Facets
The
nonNegativeInteger
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
nonNegativeInteger
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
minInclusive
Datatypes derived by
restriction from
nonNegativeInteger
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxInclusive
maxExclusive
minExclusive
assertions
The
nonNegativeInteger
datatype
has the following values for its
fundamental facets
ordered
total
bounded
false
cardinality
countably infinite
numeric
true
3.4.20.4 Derived datatypes
The following
built-in
datatypes are
derived
from
nonNegativeInteger
unsignedLong
positiveInteger
3.4.21 unsignedLong
[Definition:]
unsignedLong
is
derived
from
nonNegativeInteger
by setting the value of
maxInclusive
to be 18446744073709551615.
The
base type
of
unsignedLong
is
nonNegativeInteger
3.4.21.1 Lexical representation
unsignedLong
has a lexical representation consisting of
an optional sign followed by a
non-empty
finite-length sequence of decimal digits (#x30-#x39).
If the sign is omitted, the positive sign
('
') is assumed. If the sign is present, it
must
be
' except for lexical forms denoting zero, which may
be preceded by a positive ('
') or a negative
('
') sign. For example: 0, 12678967543233,
100000.
3.4.21.2 Canonical representation
The
canonical representation
for
unsignedLong
is defined by prohibiting certain options from the
Lexical representation (§3.4.21.1)
. Specifically,
leading zeroes are prohibited.
3.4.21.3
Facets
The
unsignedLong
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
unsignedLong
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
18446744073709551615
minInclusive
Datatypes derived by
restriction from
unsignedLong
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
unsignedLong
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.21.4 Derived datatypes
The following
built-in
datatype is
derived
from
unsignedLong
unsignedInt
3.4.22 unsignedInt
[Definition:]
unsignedInt
is
derived
from
unsignedLong
by setting the value of
maxInclusive
to be 4294967295. The
base type
of
unsignedInt
is
unsignedLong
3.4.22.1 Lexical representation
unsignedInt
has a lexical representation consisting
of an optional sign followed by a
non-empty
finite-length sequence of decimal digits (#x30-#x39).
If the sign is omitted, the positive sign
('
') is assumed. If the sign is present, it
must
be
' except for lexical forms denoting zero, which may
be preceded by a positive ('
') or a negative
('
') sign. For example: 0,
1267896754, 100000.
3.4.22.2 Canonical representation
The
canonical representation
for
unsignedInt
is defined by prohibiting certain options from the
Lexical representation (§3.4.22.1)
. Specifically,
leading zeroes are prohibited.
3.4.22.3
Facets
The
unsignedInt
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
unsignedInt
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
4294967295
minInclusive
Datatypes derived by
restriction from
unsignedInt
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
unsignedInt
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.22.4 Derived datatypes
The following
built-in
datatype is
derived
from
unsignedInt
unsignedShort
3.4.23 unsignedShort
[Definition:]
unsignedShort
is
derived
from
unsignedInt
by setting the value of
maxInclusive
to be 65535. The
base type
of
unsignedShort
is
unsignedInt
3.4.23.1 Lexical representation
unsignedShort
has a lexical representation consisting of
an optional sign followed by a
non-empty finite-length
sequence of decimal digits (#x30-#x39). If the sign is omitted, the positive sign
('
') is assumed. If the sign is present, it
must
be
' except for lexical forms denoting zero, which may
be preceded by a positive ('
') or a negative
('
') sign. For example: 0, 12678, 10000.
3.4.23.2 Canonical representation
The
canonical representation
for
unsignedShort
is defined by prohibiting certain options from the
Lexical representation (§3.4.23.1)
Specifically, the leading zeroes are prohibited.
3.4.23.3
Facets
The
unsignedShort
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
unsignedShort
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
65535
minInclusive
Datatypes derived by
restriction from
unsignedShort
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
unsignedShort
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.23.4 Derived datatypes
The following
built-in
datatype is
derived
from
unsignedShort
unsignedByte
3.4.24 unsignedByte
[Definition:]
unsignedByte
is
derived
from
unsignedShort
by setting the value of
maxInclusive
to be 255. The
base type
of
unsignedByte
is
unsignedShort
3.4.24.1 Lexical representation
unsignedByte
has a lexical representation consisting of
an optional sign followed by a
non-empty finite-length
sequence of decimal digits (#x30-#x39). If the sign is omitted, the positive sign
('
') is assumed. If the sign is present, it
must
be '
' except for lexical forms denoting zero, which may
be preceded by a positive ('
') or a negative
('
') sign. For example: 0, 126, 100.
3.4.24.2 Canonical representation
The
canonical representation
for
unsignedByte
is defined by prohibiting certain options from the
Lexical representation (§3.4.24.1)
. Specifically,
leading zeroes are prohibited.
3.4.24.3
Facets
The
unsignedByte
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
unsignedByte
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
maxInclusive
255
minInclusive
Datatypes derived by
restriction from
unsignedByte
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxExclusive
minExclusive
assertions
The
unsignedByte
datatype
has the following values for its
fundamental facets
ordered
total
bounded
true
cardinality
finite
numeric
true
3.4.25 positiveInteger
[Definition:]
positiveInteger
is
derived
from
nonNegativeInteger
by setting the value of
minInclusive
to be 1. This results in the standard
mathematical concept of the positive integer numbers.
The
value space
of
positiveInteger
is the infinite set {1,2,...}. The
base type
of
positiveInteger
is
nonNegativeInteger
3.4.25.1 Lexical representation
positiveInteger
has a lexical representation consisting
of an optional positive sign ('
') followed by a
non-empty finite-length
sequence of decimal digits (#x30-#x39),
at least one of which
must
be a digit other than '
'.
For example: 1, 12678967543233, +100000.
3.4.25.2 Canonical representation
The
canonical representation
for
positiveInteger
is defined by prohibiting certain options from the
Lexical representation (§3.4.25.1)
. Specifically, the
optional "+" sign is prohibited and leading zeroes are prohibited.
3.4.25.3
Facets
The
positiveInteger
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
fractionDigits
(fixed)
whiteSpace
collapse
(fixed)
The
positiveInteger
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[\-+]?[0-9]+
minInclusive
Datatypes derived by
restriction from
positiveInteger
may
also
specify values for the
following
constraining facets
totalDigits
enumeration
maxInclusive
maxExclusive
minExclusive
assertions
The
positiveInteger
datatype
has the following values for its
fundamental facets
ordered
total
bounded
false
cardinality
countably infinite
numeric
true
3.4.26 yearMonthDuration
[Definition:]
yearMonthDuration
is a datatype
derived
from
duration
by restricting its
lexical representations
to instances of
yearMonthDurationLexicalRep
The
value space
of
yearMonthDuration
is therefore that of
duration
restricted to those whose
seconds
property is 0. This results in a duration datatype which is totally ordered.
Note:
The always-zero
seconds
is formally retained in order that
yearMonthDuration
's (abstract) value space truly be a subset of that of
duration
An obvious implementation optimization is to ignore the zero and implement
yearMonthDuration
values simply as
integer
values.
3.4.26.1 The
yearMonthDuration
Lexical Mapping
The lexical space is reduced from that of
duration
by
disallowing
duDayFrag
and
duTimeFrag
fragments in the
lexical representations
The
yearMonthDuration
Lexical
Representation
[42]
yearMonthDurationLexicalRep
::= '
'? '
duYearMonthFrag
The lexical
space of
yearMonthDuration
consists of
strings which match the regular expression
-?P((([0-9]+Y)([0-9]+M)?)|([0-9]+M))
' or the
expression '
-?P[0-9]+(Y([0-9]+M)?|M)
', but the
formal definition of
yearMonthDuration
uses a
simpler regular expression in its
pattern
facet: '
[^DT]*
'. This pattern matches only
strings of characters which contain no 'D'
and no 'T', thus restricting the
lexical space
of
duration
to strings with no day, hour,
minute, or seconds fields.
The
canonical mapping
is that of
duration
restricted in its
range to the
lexical space
(which reduces its domain to omit any
values not in the
yearMonthDuration
value space).
Note:
The
yearMonthDuration
value whose
months
and
seconds
are both zero has no
canonical representation
in this datatype since its
canonical representation
in
duration
('
PT0S
')
is not in the
lexical space
of
yearMonthDuration
3.4.26.2
Facets
The
yearMonthDuration
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
yearMonthDuration
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[^DT]*
Datatypes derived by
restriction from
yearMonthDuration
may
also
specify values for the
following
constraining facets
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
yearMonthDuration
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
Note:
The
ordered
facet has the value
partial
even though the datatype is
in fact totally ordered, because (as explained in
ordered (§4.2.1)
),
the value of that facet is unchanged by derivation.
3.4.27 dayTimeDuration
[Definition:]
dayTimeDuration
is a datatype
derived
from
duration
by restricting its
lexical representations
to instances of
dayTimeDurationLexicalRep
The
value space
of
dayTimeDuration
is therefore that of
duration
restricted to those whose
months
property is 0. This results in a duration datatype which is totally ordered.
3.4.27.1 The
dayTimeDuration
Lexical Space
The lexical space is reduced from that of
duration
by
disallowing
duYearFrag
and
duMonthFrag
fragments in the
lexical representations
The
dayTimeDuration
Lexical Representation
[43]
dayTimeDurationLexicalRep
::= '
'? '
duDayTimeFrag
The lexical space of
dayTimeDuration
consists of
strings in the
lexical space
of
duration
which
match the regular expression '
[^YM]*[DT].*
';
this pattern eliminates all durations with year or month fields,
leaving only those with day, hour, minutes, and/or seconds
fields.
The
canonical mapping
is that of
duration
restricted
in its
range to the
lexical space
(which reduces its domain to omit any
values not in
the
dayTimeDuration
value
space).
3.4.27.2
Facets
The
dayTimeDuration
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
The
dayTimeDuration
datatype
has the following
constraining facets
with the values shown; these
facets
may
be specified
in the derivation of new types, if the
value given is at least as restrictive as the one shown:
pattern
[^YM]*(T.*)?
Datatypes derived by
restriction from
dayTimeDuration
may
also
specify values for the
following
constraining facets
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
dayTimeDuration
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
Note:
The
ordered
facet has the value
partial
even though the datatype is
in fact totally ordered, because (as explained in
ordered (§4.2.1)
),
the value of that facet is unchanged by derivation.
3.4.28 dateTimeStamp
[Definition:]
The
dateTimeStamp
datatype is
derived
from
dateTime
by giving the value
required
to its
explicitTimezone
facet.
The result is that all values of
dateTimeStamp
are required to have explicit time zone offsets
and the datatype is totally ordered.
3.4.28.1 The
dateTimeStamp
Lexical Space
As a consequence of requiring an explicit time zone offset, the
lexical space of
dateTimeStamp
is reduced from that
of
dateTime
by requiring a
timezoneFrag
fragment in the
lexical representations
The
dateTimeStamp
Lexical Representation
[44]
dateTimeStampLexicalRep
::=
yearFrag
monthFrag
dayFrag
' ((
hourFrag
minuteFrag
secondFrag
) |
endOfDayFrag
timezoneFrag
Constraint:
Day-of-month Representations
Note:
For details of the
Day-of-month Representations (§3.3.7.2)
constraint, see
dateTime
, from which the constraint is inherited.
In other words, the lexical space of
dateTimeStamp
consists of strings which are in the
lexical space
of
dateTime
and which
also match the regular expression
.*(Z|(\+|-)[0-9][0-9]:[0-9][0-9])
'.
The
lexical mapping
is that of
dateTime
restricted to
the
dateTimeStamp
lexical space.
The
canonical mapping
is that of
dateTime
restricted
to the
dateTimeStamp
value
space.
3.4.28.2
Facets
The
dateTimeStamp
datatype
and all datatypes derived from it by restriction have the
following
constraining facets
with
fixed
values; these
facets
must not
be changed from the values shown:
whiteSpace
collapse
(fixed)
explicitTimezone
required
(fixed)
Datatypes derived by
restriction from
dateTimeStamp
may
also
specify values for the
following
constraining facets
pattern
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
The
dateTimeStamp
datatype
has the following values for its
fundamental facets
ordered
partial
bounded
false
cardinality
countably infinite
numeric
false
Note:
The
ordered
facet has the value
partial
even though the datatype is
in fact totally ordered, because (as explained in
ordered (§4.2.1)
),
the value of that facet is unchanged by derivation.
4 Datatype components
The preceding sections of this
specification have described datatypes in a way largely
independent of their use in the particular context of
schema-aware processing
as
defined in
[XSD 1.1 Part 1: Structures]
This section presents the mechanisms necessary to integrate datatypes into
the context of
[XSD 1.1 Part 1: Structures]
, mostly in terms of
the
schema
component
abstraction introduced there. The account of datatypes given in this
specification is also intended to be useful in other contexts.
Any specification or other formal system intending to use datatypes as
defined above, particularly if definition of new datatypes via
facet-based restriction is envisaged, will need to provide analogous
mechanisms for some, but not necessarily all, of what follows below.
For example, the
{target namespace}
and
{final}
properties are required because of
particular aspects of
[XSD 1.1 Part 1: Structures]
which are not
in principle necessary for the use of datatypes as defined here.
The following sections provide full details on the properties and
significance of each kind of schema component involved in datatype
definitions. For each property, the kinds of values it is allowed to have is
specified. Any property not identified as optional is required to
be present; optional properties which are not present have
absent
as their value.
Any property identified as a having a set, subset or
list
value may have an empty value unless this is explicitly ruled out: this is
not the same as
absent
Any property value identified as a superset or a subset of some set may
be equal to that set, unless a proper superset or subset is explicitly
called for.
For more information on the notion of schema components,
see
Schema Component Details
of
[XSD 1.1 Part 1: Structures]
[Definition:]
component may be referred to as the
owner
of its properties, and of the values of
those properties.
4.1 Simple Type Definition
4.1.1
The Simple Type Definition Schema Component
4.1.2
XML Representation of Simple Type Definition Schema Components
4.1.3
Constraints on XML Representation of Simple Type Definition
4.1.4
Simple Type Definition Validation Rules
4.1.5
Constraints on Simple Type Definition Schema Components
4.1.6
Built-in Simple Type Definitions
Simple Type Definitions provide for:
In the case of
primitive
datatypes,
identifying a datatype with its definition in this specification.
In the case of
constructed
datatypes,
defining the datatype in terms of other datatypes.
Attaching a
QName
to the datatype.
4.1.1 The Simple Type Definition Schema Component
The Simple Type Definition schema component has the following properties:
Schema Component:
Simple Type Definition
{annotations}
A sequence of
Annotation
components.
{name}
An xs:NCName value. Optional.
{target namespace}
An xs:anyURI value. Optional.
{final}
A subset of
restriction
extension
list
union
{context}
Required if
{name}
is
absent
, otherwise
must
be
absent
Either an
Attribute Declaration
, an
Element Declaration
, a
Complex Type Definition
or a
Simple Type Definition
{base type definition}
Type Definition
component. Required.
With one exception, the
{base type definition}
of any
Simple Type Definition
is a
Simple Type Definition
The exception is
anySimpleType
, which has
anyType
, a
Complex Type
Definition
, as its
{base type definition}
{facets}
A set of
Constraining Facet
components.
{fundamental facets}
A set of
Fundamental Facet
components.
{variety}
One of {
atomic
list
union
}. Required for all
Simple Type Definition
except
anySimpleType
in which it is
absent
{primitive type definition}
Simple Type Definition
component. With one exception, required if
{variety}
is
atomic
, otherwise
must
be
absent
. The exception
is
anyAtomicType
, whose
{primitive type definition}
is
absent
If
not
absent
must
be a
primitive
built-in definition.
{item type definition}
Simple Type Definition
component. Required if
{variety}
is
list
, otherwise
must
be
absent
The value of this property
must
be
a primitive or ordinary simple type definition
with
{variety}
atomic
or
an ordinary simple type definition
with
{variety}
union
whose basic members are all atomic;
the value
must not
itself be
a list type
(have
{variety}
list
or have any basic members which are list types.
{member type definitions}
A sequence of primitive or ordinary
Simple Type Definition
components.
Must
be present
(but
may
be empty)
if
{variety}
is
union
otherwise
must
be
absent
The sequence may contain any primitive or ordinary simple type definition, but
must not
contain any special type definitions.
Simple type definitions are
identified by their
{name}
and
{target namespace}
. Except for
anonymous
Simple Type Definition
s (those
with no
{name}
),
Simple Type Definition
must
be uniquely identified within a
schema.
Within a valid schema,
each
Simple Type Definition
uniquely determines
one datatype. The
value space
lexical space
lexical mapping
, etc., of a
Simple Type Definition
are the
value space
lexical space
, etc., of the datatype
uniquely determined (or "defined")
by that
Simple Type Definition
If
{variety}
is
atomic
then the
value space
of the datatype
defined will be a subset of the
value space
of
{base type definition}
(which is a subset
of the
value space
of
{primitive type definition}
). If
{variety}
is
list
then the
value space
of the datatype
defined will be the set of
(possibly empty)
finite-length sequences
of values from the
value space
of
{item type definition}
If
{variety}
is
union
then the
value space
of the datatype
defined will be a subset
(possibly an improper subset) of
the union of the
value spaces
of each
Simple Type Definition
in
{member type definitions}
If
{variety}
is
atomic
then the
{variety}
of
{base type definition}
must
be
atomic
unless the
{base type definition}
is
anySimpleType
If
{variety}
is
list
then the
{variety}
of
{item type definition}
must
be either
atomic
or
union
, and if
{item type definition}
is
union
then all its
basic members
must
be
atomic
If
{variety}
is
union
then
{member type definitions}
must
be a list of
Simple Type Definition
s.
The
{facets}
property
determines the
value space
and
lexical space
of the datatype
being defined by imposing constraints which
are to be satisfied by all valid
values and
lexical representations
The
{fundamental facets}
property provides some
basic information about the datatype being defined: its cardinality,
whether an ordering is defined for it by this specification,
whether it has upper and lower bounds, and whether it is numeric.
If
{final}
is the empty set then the type can be used
in deriving other types; the explicit values
restriction
list
and
union
prevent further derivations of
Simple Type Definition
by
facet-based restriction
list
and
union
respectively; the explicit value
extension
prevents any derivation of
Complex Type Definitions
by extension.
The
{context}
property is only relevant for anonymous type definitions, for which its value
is the component in which this type definition appears as the value of a
property, e.g.
{item type definition}
or
{base type definition}
4.1.2 XML Representation of Simple Type Definition Schema Components
The XML representation for a
Simple Type Definition
schema component
is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
simpleType
Element Information Item et al.
#all
| List of (
list
union
restriction
extension
))
id =
ID
name =
NCName
{any attributes with non-schema namespace . . .}
Content:
annotation
?, (
restriction
list
union
))
QName
id =
ID
{any attributes with non-schema namespace . . .}
Content:
annotation
?, (
simpleType
?, (
minExclusive
minInclusive
maxExclusive
maxInclusive
totalDigits
fractionDigits
length
minLength
maxLength
enumeration
whiteSpace
pattern
assertion
explicitTimezone
{any with namespace: ##other}
)*))
ID
itemType =
QName
{any attributes with non-schema namespace . . .}
Content:
annotation
?,
simpleType
?)
ID
memberTypes = List of
QName
{any attributes with non-schema namespace . . .}
Content:
annotation
?,
simpleType
*)
Simple Type Definition
Schema Component
Property
Representation
{name}
The
actual value
of the
name
[attribute]
, if
present on the
element,
otherwise
absent
{target namespace}
The
actual value
of the
targetNamespace
[attribute]
of the parent
schema
element information
item, if present,
otherwise
absent
{base type definition}
The appropriate
case
among the following:
If
the
alternative is chosen,
then
the type definition
resolved
to by the
actual value
of the
base
[attribute]
of
if present, otherwise the
type definition corresponding to the
among
the
[children]
of
If
the
or
alternative is chosen,
then
anySimpleType
{final}
A subset of
restriction
extension
list
union
, determined as follows.
[Definition:]
Let
FS
be
the
actual value
of the
final
[attribute]
if present, otherwise the
actual value
of the
finalDefault
[attribute]
of the ancestor
schema
element,
if present, otherwise the empty string.
Then the property value is
the appropriate
case
among the following:
If
FS
is the empty string,
then
the empty set;
If
FS
is '
#all
',
then
restriction
extension
list
union
otherwise
Consider
FS
as
a space-separated list, and include
restriction
if
restriction
' is in that list, and similarly for
extension
list
and
union
{context}
The appropriate
case
among the following:
If
the
name
[attribute]
is present,
then
absent
otherwise
the appropriate
case
among the following:
2.1
If
the parent element information item is
then
the corresponding
Attribute Declaration
2.2
If
the parent element information item is
then
the corresponding
Element Declaration
2.3
If
the parent element information item is
or
then
the
Simple Type Definition
corresponding to the grandparent
element information item
2.4
otherwise
(the parent element information item is
),
the appropriate
case
among the following:
2.4.1
If
the grandparent element information item is
then
the
Simple Type Definition
corresponding to the grandparent
2.4.2
otherwise
(the grandparent element information item is
),
the
Simple Type Definition
which is the
{content type}
of the
Complex Type Definition
corresponding to the great-grandparent
element information item.
{variety}
If
the
alternative is chosen,
then
list
, otherwise if the
alternative is
chosen, then
union
, otherwise (the
alternative is chosen) the
{variety}
of the
{base type definition}
{facets}
The appropriate
case
among the following:
If
the
alternative is chosen,
then
the set of
Constraining Facet
components
obtained by
overlaying
the
{facets}
of the
{base type definition}
with the
set of
Constraining Facet
components corresponding to those
[children]
of
which specify facets, as
defined in
Schema Component Constraint: Simple Type Restriction (Facets)
If
the
alternative is chosen,
then
a set with one member, a
whiteSpace
facet with
{value}
collapse
and
{fixed}
true
otherwise
the empty set
{fundamental facets}
Based on
{variety}
{facets}
{base type definition}
and
{member type definitions}
, a set of
Fundamental Facet
components, one
each as specified in
The ordered Schema Component (§4.2.1.1)
The bounded Schema Component (§4.2.2.1)
The cardinality Schema Component (§4.2.3.1)
and
The numeric Schema Component (§4.2.4.1)
{annotations}
The
annotation mapping
of the set of elements containing the
, and
the
, the
, or the
[child]
whichever is present,
as defined in section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
[Definition:]
The
ancestors
of a
type definition
are its
{base type definition}
and the
ancestors
of its
{base type definition}
(The ancestors of a
Simple Type Definition
in the type hierarchy are themselves
type definitions
; they are distinct from
the XML elements which may be ancestors, in the XML document
hierarchy, of the
element which
declares
.)
If the
{variety}
is
atomic
, the following additional property
mapping also applies:
Atomic Simple Type Definition
Schema Component
Property
Representation
{primitive type definition}
From among the
ancestors
of this
Simple Type Definition
, that
Simple Type Definition
which corresponds to a
primitive
datatype.
Example
An electronic commerce schema might define a datatype called
SKU
(the barcode number that appears on products) from the
built-in
datatype
string
by
supplying a value for the
pattern
facet.
In this case, '
SKU
' is the name of the new
user-defined
datatype,
string
is
its
base type
and
pattern
is the facet.
If the
{variety}
is
list
, the following
additional property mappings also apply:
List Simple Type Definition
Schema Component
Property
Representation
{item type definition}
The appropriate
case
among the following:
If
the
{base type definition}
is
anySimpleType
then
the
Simple Type Definition
(a)
resolved
to by the
actual value
of the
itemType
[attribute]
of
or (b)
corresponding to the
among
the
[children]
of
, whichever is present.
Note:
In this
case, a
element will invariably be present; it will
invariably have either an
itemType
[attribute]
or a
[child]
, but not both.
otherwise
(that is, the
{base type definition}
is not
anySimpleType
), the
{item type definition}
of the
{base type definition}
Note:
In this case, a
element will invariably be present.
Example
A system might want to store lists of floating point values.
In this case,
listOfFloat
is the name of the new
user-defined
datatype,
float
is its
item type
and
list
is the
derivation method.
If the
{variety}
is
union
, the following
additional property mappings also apply:
Union Simple Type Definition
Schema Component
Property
Representation
{member type definitions}
The appropriate
case
among the following:
If
the
{base type definition}
is
anySimpleType
then
the sequence of (a) the
Simple Type Definition
(a)
resolved
to by the items in the
actual value
of the
memberTypes
[attribute]
of
, if
any, and (b) those corresponding to the
among the
[children]
of
, if any, in order.
Note:
In this case, a
element will invariably be
present; it will invariably have either a
memberTypes
[attribute]
or one or more
[children]
or both.
otherwise
(that is, the
{base type definition}
is not
anySimpleType
), the
{member type definitions}
of the
{base type definition}
Note:
In this case, a
element will invariably
be present.
Example
As an example, taken from a typical display oriented text markup language,
one might want to express font sizes as an integer between 8 and 72, or with
one of the tokens "small", "medium" or "large". The
union
Simple Type Definition
below would accomplish that.
A header
this is a test
A datatype can be
constructed
from a
primitive
datatype or
an
ordinary
datatype by one of three means:
by
facet-based restriction
by
list
or by
union
4.1.3 Constraints on XML Representation of Simple Type Definition
Schema Representation Constraint: itemType attribute or simpleType child
Either the
itemType
[attribute]
or the
[child]
of the
element
must
be present, but not both.
Schema Representation Constraint: base attribute or simpleType child
Either the
base
[attribute]
or the
simpleType
[child]
of the
element
must
be present, but not both.
Schema Representation Constraint: memberTypes attribute or simpleType children
Either the
memberTypes
[attribute]
of the
element
must
be non-empty or
there
must
be at least one
simpleType
[child]
4.1.4 Simple Type Definition Validation Rules
Validation Rule: Facet Valid
A value in a
value space
is facet-valid with
respect to a
constraining facet
component
if and only if:
the value is facet-valid with respect to the particular
constraining facet
as specified below.
Validation Rule: Datatype Valid
literal
is datatype-valid with respect to a
Simple Type Definition
if and only if it is a member of the
lexical space
of the
corresponding datatype.
Note:
Since every value in the
value space
is denoted by some
literal
, and every
literal
in the
lexical space
maps to
some value, the requirement that the
literal
be in the
lexical space
entails the requirement that the value it
maps to should fulfill all of the constraints imposed by the
{facets}
of the datatype. If
the datatype is a
list
, the Datatype Valid constraint also
entails that each whitespace-delimited token in the list
be datatype-valid against the
item type
of the list.
If the datatype is a
union
, the Datatype Valid constraint
entails that the
literal
be datatype-valid against at
least one of the
member types
That is, the constraints on
Simple Type Definition
s and on
datatype
derivation
defined in this specification have as a
consequence that a
literal
is datatype-valid with
respect to a
Simple Type Definition
if and only if
either
corresponds to a
special
datatype or
all
of the following are true:
If there is a
pattern
in
{facets}
, then
is
pattern valid (§4.3.4.4)
with respect to the
pattern
If there are other
lexical
facets
in
{facets}
, then
is facet-valid with respect
to them.
The appropriate case among the following is true:
2.1
If the
{variety}
of
is
atomic
then
is in the
lexical space
of the
{primitive type definition}
of
, as defined in the
appropriate documentation.
Let
be the
member of the
value space
of the
{primitive type definition}
of
mapped to by
as defined in the appropriate documentation.
Note:
For
built-in
primitives
, the
"appropriate documentation" is the relevant
section of this specification. For
implementation-defined
primitives
it is the normative specification of the
primitive
, which
will typically be included in, or referred to from, the
implementation's documentation.
2.2
If the
{variety}
of
is
list
, then
each space-delimited substring of
is Datatype Valid with
respect to the
{item type definition}
of
. Let
be the sequence consisting of the values identified by
Datatype Valid for each of those substrings, in order.
2.3
If the
{variety}
of
is
union
then
is Datatype Valid with respect to at least one
member of the
{member type definitions}
of
. Let
be the
active basic member
of
for
. Let
be the value identified by Datatype Valid for
with respect to
, as determined by the
appropriate sub-clause of clause
above,
is
Facet Valid (§4.1.4)
with respect to each member of the
{facets}
of
which is a
value-based
(and not a
pre-lexical
or
lexical
facet.
Note that
whiteSpace
facets and
other
pre-lexical
facets
do not take part in checking Datatype
Valid. In cases where this specification is used in conjunction with
schema-validation of XML documents,
such facets are used to
normalize infoset values
before
the normalized results
are checked for datatype validity. In the case of unions the
pre-lexical
facets to use are those
associated with
in
clause
2.3
above.
When more than one
pre-lexical
facet
applies, the
whiteSpace
facet is applied first; the order in
which
implementation-defined
facets
are applied is
implementation-defined
4.1.5 Constraints on Simple Type Definition Schema Components
Schema Component Constraint: Applicable Facets
The
constraining facets
which are allowed to be members of
{facets}
depend on
the
{variety}
and
{primitive type definition}
of the type, as
follows:
If
{variety}
is
absent
then no facets are applicable.
(This is true for
anySimpleType
.)
If
{variety}
is
list
then the applicable facets are
assertions
length
minLength
maxLength
pattern
enumeration
, and
whiteSpace
If
{variety}
is
union
, then
the applicable facets are
pattern
enumeration
, and
assertions
If
{variety}
is
atomic
and
{primitive type definition}
is
absent
then no facets are applicable.
(This is true for
anyAtomicType
.)
In all other cases (
{variety}
is
atomic
and
{primitive type definition}
is not
absent
), then the applicable facets are
shown in the table below.
{primitive type definition}
applicable
{facets}
string
length
minLength
maxLength
pattern
enumeration
whiteSpace
assertions
boolean
pattern
whiteSpace
assertions
float
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
double
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
decimal
totalDigits
fractionDigits
pattern
whiteSpace
enumeration
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
duration
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
dateTime
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
time
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
date
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
gYearMonth
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
gYear
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
gMonthDay
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
gDay
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
gMonth
pattern
enumeration
whiteSpace
maxInclusive
maxExclusive
minInclusive
minExclusive
assertions
explicitTimezone
hexBinary
length
minLength
maxLength
pattern
enumeration
whiteSpace
assertions
base64Binary
length
minLength
maxLength
pattern
enumeration
whiteSpace
assertions
anyURI
length
minLength
maxLength
pattern
enumeration
whiteSpace
assertions
QName
length
minLength
maxLength
pattern
enumeration
whiteSpace
assertions
NOTATION
length
minLength
maxLength
pattern
enumeration
whiteSpace
assertions
Note:
For any
implementation-defined
primitive types,
it is
implementation-defined
which constraining facets are
applicable to them.
Similarly, for any
implementation-defined
constraining facets,
it is
implementation-defined
which
primitives
they
apply to.
4.1.6 Built-in Simple Type Definitions
The
Simple Type Definition
of
anySimpleType
is
present in every schema. It has the following properties:
Simple type definition of
anySimpleType
Property
Value
{name}
anySimpleType
{target namespace}
{final}
The empty set
{context}
absent
{base type definition}
anyType
{facets}
The empty set
{fundamental facets}
The empty set
{variety}
absent
{primitive type definition}
absent
{item type definition}
absent
{member type definitions}
absent
{annotations}
The empty sequence
The
definition of
anySimpleType
is the root of the Simple Type Definition
hierarchy;
as such it mediates between the other
simple type definitions,
which all eventually trace back to it via their
{base type definition}
properties,
and the
definition of
anyType
which is
its
{base type definition}
The
Simple Type Definition
of
anyAtomicType
is
present in every schema. It has the following properties:
Simple type definition of
anyAtomicType
Property
Value
{name}
anyAtomicType
{target namespace}
{final}
The empty set
{context}
absent
{base type definition}
anySimpleType
{facets}
The empty set
{fundamental facets}
The empty set
{variety}
atomic
{primitive type definition}
absent
{item type definition}
absent
{member type definitions}
absent
{annotations}
The empty sequence
Simple type definitions for all the built-in primitive datatypes,
namely
string
boolean
float
double
decimal
dateTime
duration
time
date
gMonth
gMonthDay
gDay
gYear
gYearMonth
hexBinary
base64Binary
anyURI
are present by definition
in every schema. All have a very similar structure, with only the
{name}
, the
{primitive type definition}
(which is self-referential),
the
{fundamental facets}
and in one case the
{facets}
varying from one to the
next:
Simple Type Definition corresponding to the built-in primitive datatypes
Property
Value
{name}
[as appropriate]
{target namespace}
{base type definition}
anyAtomicType Definition
{final}
The empty set
{variety}
atomic
{primitive type definition}
[this
Simple Type Definition
itself]
{facets}
{a
whiteSpace
facet with
{value}
collapse
and
{fixed}
true
in all cases except
string
, which has
{value}
preserve
and
{fixed}
false
{fundamental facets}
[as appropriate]
{context}
absent
{item type definition}
absent
{member type definitions}
absent
{annotations}
The empty sequence
Implementation-defined
primitives
must
have a
Simple Type Definition
with
the values shown above, with the following exceptions.
The
{facets}
property
must
contain a
whiteSpace
facet, the value of which is
implementation-defined
. It
may
contain other facets,
whether defined in this specification or
implementation-defined
The value of
{fundamental facets}
is
implementation-defined
The value of
{annotations}
may
be empty, but need not be.
Note:
It is a consequence of the rule just given that each
implementation-defined
primitive
will have an
expanded name
by which it can be referred to.
Note:
Implementation-defined
datatypes will normally have a value
other than '
' for the
{target namespace}
property. That namespace is controlled by the W3C and
datatypes will be added to it only by W3C or its designees.
Similarly,
Simple Type Definition
s for all the built-in
ordinary
datatypes are present by definition in every schema, with properties
as specified in
Other Built-in Datatypes (§3.4)
and as represented
in XML in
Illustrative XML representations for the built-in ordinary type definitions (§C.2)
Simple Type Definition corresponding to the built-in ordinary datatypes
Property
Value
{name}
[as appropriate]
{target namespace}
{base type definition}
[as specified in the appropriate
sub-section of
Other Built-in Datatypes (§3.4)
{final}
The empty set
{variety}
atomic
or
list
, as specified in the appropriate
sub-section of
Other Built-in Datatypes (§3.4)
{primitive type definition}
[if
{variety}
is
atomic
, then the
{primitive type definition}
of the
{base type definition}
, otherwise
absent
{facets}
[as specified in the appropriate
sub-section of
Other Built-in Datatypes (§3.4)
{fundamental facets}
[as specified in the appropriate
sub-section of
Other Built-in Datatypes (§3.4)
{context}
absent
{item type definition}
if
{variety}
is
atomic
, then
absent
, otherwise as specified in the appropriate
sub-section of
Other Built-in Datatypes (§3.4)
{member type definitions}
absent
{annotations}
As shown in the XML representations
of the ordinary built-in datatypes in
Illustrative XML representations for the built-in ordinary type definitions (§C.2)
4.2 Fundamental Facets
4.2.1
ordered
4.2.1.1
The ordered Schema Component
4.2.2
bounded
4.2.2.1
The bounded Schema Component
4.2.3
cardinality
4.2.3.1
The cardinality Schema Component
4.2.4
numeric
4.2.4.1
The numeric Schema Component
[Definition:]
Each
fundamental facet
is a
schema component that provides a limited piece of information about
some aspect of each datatype.
All
fundamental
facet
components are defined in this section.
For example,
cardinality
is a
fundamental facet
Most
fundamental facets
are given a value
fixed with each primitive datatype's definition, and this value is not changed by
subsequent
derivations
(even when
it would perhaps be reasonable to expect an application to give a more accurate value based
on the constraining facets used to define the
derivation
). The
cardinality
and
bounded
facets
are exceptions to this rule; their values may change as a result of certain
derivations
Note:
Schema components are identified by kind. "Fundamental"
is not a kind of component. Each kind of
fundamental facet
("ordered",
"bounded", etc.) is
a separate kind of schema component.
fundamental facet
can occur only
in the
{fundamental facets}
of a
Simple Type Definition
, and this is the
only place where
fundamental facet
components
occur. Each kind of
fundamental facet
component occurs (once) in each
Simple Type Definition
's
{fundamental facets}
set.
Note:
The value of any
fundamental facet
component can always
be calculated from other properties of its
owner
Fundamental facets are not required for schema processing,
but some applications use them.
4.2.1 ordered
For some datatypes,
this document specifies an order relation for their value spaces (see
Order (§2.2.3)
); the
ordered
facet reflects
this. It takes the values
total
partial
and
false
, with the meanings described below.
For the
primitive
datatypes,
the value of the
ordered
facet is
specified in
Fundamental Facets (§F.1)
For
ordinary
datatypes, the value is inherited without change
from the
base type
For a
list
, the value is always
false
for a
union
, the value is computed as described below.
false
value means no order is prescribed;
total
value
assures that the prescribed order is a total
order; a
partial
value means
that the prescribed order is a partial
order, but not (for the primitive type in question) a total order.
Note:
The value
false
in the
ordered
facet does not
mean no partial or total ordering
exists
for the value
space, only that none is specified by this document for use in
checking upper and lower bounds. Mathematically, any set of values
possesses at least one
trivial partial ordering, in which every value
pair that is not equal is incomparable.
Note:
When new datatypes are derived from datatypes with partial orders,
the constraints imposed can sometimes result in a value space
for which the ordering is total, or trivial. The value of the
ordered
facet is not, however, changed to reflect this.
The value
partial
should therefore be interpreted with
appropriate caution.
[Definition:]
value space
, and hence a datatype, is said to be
ordered
if some
members of the
value space
are
drawn from a
primitive
datatype for which
the table in
Fundamental Facets (§F.1)
specifies
the value
total
or
partial
for
the
ordered
facet.
Note:
Some of the "real-world" datatypes which are the basis for those defined herein
are ordered in some applications, even though no order is prescribed for schema-processing
purposes. For example,
boolean
is sometimes ordered, and
string
and
list
datatypes
constructed
from
ordered
atomic
datatypes are sometimes given "lexical"
orderings. They are
not
ordered for schema-processing purposes.
4.2.1.1 The ordered Schema Component
Schema Component:
ordered
, a kind of
Fundamental Facet
{value}
One of {
false
partial
total
}. Required.
{value}
depends on
the
owner's
{variety}
{facets}
and
{member type definitions}
The appropriate
case
among the following
must
be true:
If
the
owner's
{variety}
is
atomic
then
the appropriate
case
among the following
must
be true:
1.1
If
the
owner
is
primitive
then
{value}
is as specified in the
table in
Fundamental Facets (§F.1)
1.2
otherwise
{value}
is the
owner's
{base type definition}
's
ordered
{value}
If
the
owner's
{variety}
is
list
then
{value}
is
false
otherwise
the
owner's
{variety}
is
union
the appropriate
case
among the following
must
be true:
3.1
If
every
basic member
of the
owner
has
{variety}
atomic and has the same
{primitive type definition}
then
{value}
is the same as the
ordered
component's
{value}
in that
primitive
type definition's
{fundamental facets}
3.2
If
each member of the
owner's
{member type definitions}
has an
ordered
component in its
{fundamental facets}
whose
{value}
is
false
then
{value}
is
false
3.3
otherwise
{value}
is
partial
4.2.2 bounded
Some ordered datatypes have the property that
there is one value greater than or equal to every other value, and
another that is
less than or equal to every other value. (In the case of
ordinary
datatypes, these two values
are
not necessarily in the value space of the derived datatype,
but they will always be
in the value
space of the primitive datatype from which they have been derived.)
The
bounded
facet value is
boolean
and is
generally
true
for such
bounded
datatypes.
However, it will remain
false
when the mechanism for imposing
such a bound is difficult to detect, as, for example, when the
boundedness occurs because of derivation using a
pattern
component.
4.2.2.1 The bounded Schema Component
Schema Component:
bounded
, a kind of
Fundamental Facet
{value}
An xs:boolean value. Required.
{value}
depends on
the
owner's
{variety}
{facets}
and
{member type definitions}
When the
owner
is
primitive
{value}
is as specified in the
table in
Fundamental Facets (§F.1)
. Otherwise, when the
owner's
{variety}
is
atomic
if one of
minInclusive
or
minExclusive
and one of
maxInclusive
or
maxExclusive
are members of
the
owner's
{facets}
set, then
{value}
is
true
otherwise
{value}
is
false
When the
owner's
{variety}
is
list
{value}
is
false
When the
owner's
{variety}
is
union
, if
{value}
is
true
for every
member of the
owner's
{member type definitions}
set and all of the
owner's
basic members
have the same
{primitive type definition}
, then
{value}
is
true
; otherwise
{value}
is
false
4.2.3 cardinality
Every value space has a specific number of members. This number can be characterized as
finite
or
infinite
. (Currently there are no datatypes with infinite
value spaces larger than
countable
.) The
cardinality
facet value is
either
finite
or
countably infinite
and is generally
finite
for datatypes with
finite value spaces. However, it will remain
countably infinite
when the mechanism for
causing finiteness is difficult to detect, as, for example, when finiteness occurs because of a
derivation using a
pattern
component.
4.2.3.1 The cardinality Schema Component
Schema Component:
cardinality
, a kind of
Fundamental Facet
{value}
One of {
finite
countably infinite
}. Required.
{value}
depends on the
owner's
{variety}
{facets}
, and
{member type definitions}
When the
owner
is
primitive
{value}
is as specified in the
table in
Fundamental Facets (§F.1)
. Otherwise, when
the
owner's
{variety}
is
atomic
{value}
is
countably infinite
unless
any
of the following
conditions are true, in which case
{value}
is
finite
the
owner's
{base type definition}
's
cardinality
{value}
is
finite
at least one of
length
maxLength
or
totalDigits
is a member of the
owner's
{facets}
set,
all
of the following are true:
one of
minInclusive
or
minExclusive
is a member of the
owner's
{facets}
set
one of
maxInclusive
or
maxExclusive
is a member of the
owner's
{facets}
set
either
of the following are true:
fractionDigits
is a member of the
owner's
{facets}
set
{primitive type definition}
is one of
date
gYearMonth
gYear
gMonthDay
gDay
or
gMonth
When the
owner's
{variety}
is
list
if
length
or both
minLength
and
maxLength
are members of the
owner's
{facets}
set
and the
owner's
{item type definition}
's
cardinality
{value}
is
finite
then
{value}
is
finite
otherwise
{value}
is
countably infinite
When the
owner's
{variety}
is
union
if
cardinality
's
{value}
is
finite
for every member of the
owner's
{member type definitions}
set then
{value}
is
finite
otherwise
{value}
is
countably infinite
4.2.4 numeric
Some value spaces are made up of things that
are
conceptually
numeric
, others are
not. The
numeric
facet value indicates which are
considered numeric.
4.2.4.1 The numeric Schema Component
Schema Component:
numeric
, a kind of
Fundamental Facet
{value}
An xs:boolean value. Required.
{value}
depends on the
owner's
{variety}
{facets}
{base type definition}
and
{member type definitions}
When the
owner
is
primitive
{value}
is as specified in the
table in
Fundamental Facets (§F.1)
. Otherwise, when the
owner's
{variety}
is
atomic
{value}
is inherited from
the
owner's
{base type definition}
's
numeric
{value}
When the
owner's
{variety}
is
list
{value}
is
false
When the
owner's
{variety}
is
union
if
numeric
's
{value}
is
true
for every member of the
owner's
{member type definitions}
set then
{value}
is
true
otherwise
{value}
is
false
4.3 Constraining Facets
4.3.1
length
4.3.1.1
The length Schema Component
4.3.1.2
XML Representation of length Schema Components
4.3.1.3
length Validation Rules
4.3.1.4
Constraints on length Schema Components
4.3.2
minLength
4.3.2.1
The minLength Schema Component
4.3.2.2
XML Representation of minLength Schema Component
4.3.2.3
minLength Validation Rules
4.3.2.4
Constraints on minLength Schema Components
4.3.3
maxLength
4.3.3.1
The maxLength Schema Component
4.3.3.2
XML Representation of maxLength Schema Components
4.3.3.3
maxLength Validation Rules
4.3.3.4
Constraints on maxLength Schema Components
4.3.4
pattern
4.3.4.1
The pattern Schema Component
4.3.4.2
XML Representation of pattern Schema Components
4.3.4.3
Constraints on XML Representation of pattern
4.3.4.4
pattern Validation Rules
4.3.4.5
Constraints on pattern Schema Components
4.3.5
enumeration
4.3.5.1
The enumeration Schema Component
4.3.5.2
XML Representation of enumeration Schema Components
4.3.5.3
Constraints on XML Representation of enumeration
4.3.5.4
enumeration Validation Rules
4.3.5.5
Constraints on enumeration Schema Components
4.3.6
whiteSpace
4.3.6.1
The whiteSpace Schema Component
4.3.6.2
XML Representation of whiteSpace Schema Components
4.3.6.3
whiteSpace Validation Rules
4.3.6.4
Constraints on whiteSpace Schema Components
4.3.7
maxInclusive
4.3.7.1
The maxInclusive Schema Component
4.3.7.2
XML Representation of maxInclusive Schema Components
4.3.7.3
maxInclusive Validation Rules
4.3.7.4
Constraints on maxInclusive Schema Components
4.3.8
maxExclusive
4.3.8.1
The maxExclusive Schema Component
4.3.8.2
XML Representation of maxExclusive Schema Components
4.3.8.3
maxExclusive Validation Rules
4.3.8.4
Constraints on maxExclusive Schema Components
4.3.9
minExclusive
4.3.9.1
The minExclusive Schema Component
4.3.9.2
XML Representation of minExclusive Schema Components
4.3.9.3
minExclusive Validation Rules
4.3.9.4
Constraints on minExclusive Schema Components
4.3.10
minInclusive
4.3.10.1
The minInclusive Schema Component
4.3.10.2
XML Representation of minInclusive Schema Components
4.3.10.3
minInclusive Validation Rules
4.3.10.4
Constraints on minInclusive Schema Components
4.3.11
totalDigits
4.3.11.1
The totalDigits Schema Component
4.3.11.2
XML Representation of totalDigits Schema Components
4.3.11.3
totalDigits Validation Rules
4.3.11.4
Constraints on totalDigits Schema Components
4.3.12
fractionDigits
4.3.12.1
The fractionDigits Schema Component
4.3.12.2
XML Representation of fractionDigits Schema Components
4.3.12.3
fractionDigits Validation Rules
4.3.12.4
Constraints on fractionDigits Schema Components
4.3.13
Assertions
4.3.13.1
The assertions Schema Component
4.3.13.2
XML Representation of assertions Schema Components
4.3.13.3
Assertions Validation Rules
4.3.13.4
Constraints on assertions Schema Components
4.3.14
explicitTimezone
4.3.14.1
The explicitTimezone Schema Component
4.3.14.2
XML Representation of explicitTimezone Schema Components
4.3.14.3
explicitTimezone Validation Rules
4.3.14.4
Constraints on explicitTimezone Schema Components
[Definition:]
Constraining facets
are schema components whose values may be set or changed
during
derivation
(subject to facet-specific controls)
to control various aspects of the derived datatype.
All
constraining facet
components
defined by this specification
are
defined in this section. For example,
whiteSpace
is a
constraining facet
Constraining Facets
are given a value as part of
the
derivation
when an
ordinary
datatype is defined by
restricting
primitive
or
ordinary
datatype; a few
constraining facets
have default values
that are also provided for
primitive
datatypes.
Note:
Schema components are identified by kind. "Constraining"
is not a kind of component. Each kind of
constraining facet
("whiteSpace",
"length", etc.) is a separate kind of schema component.
This specification distinguishes three kinds of constraining facets:
[Definition:]
A constraining facet which
is used to normalize an initial
literal
before checking
to see whether the resulting character sequence is a member of a datatype's
lexical space
is a
pre-lexical
facet.
This specification defines just one
pre-lexical
facet:
whiteSpace
[Definition:]
A constraining facet which
directly restricts the
lexical space
of a datatype
is a
lexical
facet.
This specification defines just one
lexical
facet:
pattern
Note:
As specified normatively elsewhere,
lexical
facets can have an indirect
effect on the
value space
: if every lexical representation of a value
is removed from the
lexical space
, the value itself is removed
from the
value space
[Definition:]
A constraining facet which
directly restricts the
value space
of a datatype
is a
value-based
facet.
Most of the constraining facets defined by this specification
are
value-based
facets.
Note:
As specified normatively elsewhere,
value-based
facets can have an indirect
effect on the
lexical space
: if a value
is removed from the
value space
, its lexical representations
are removed
from the
lexical space
Conforming processors
must
support all the facets defined in this section.
It is
implementation-defined
whether a processor supports other
constraining facets.
[Definition:]
An
constraining facet
which is not supported by
the processor in use is
unknown
Note:
A reference to an
unknown
facet might be a reference to
an
implementation-defined
facet supported by some other processor,
or might be the result of a typographic error, or might
have some other explanation.
The descriptions of individual facets given
below include both constraints on
Simple Type Definition
components
and rules for checking the datatype validity of a given literal against
a given datatype. The validation rules typically depend upon having
a full knowledge of the datatype; full knowledge of the datatype,
in turn, depends on having a fully instantiated
Simple Type Definition
A full instantiation of the
Simple Type Definition
, and the checking
of the component constraints, require knowledge of the
base type
It follows that if a datatype's
base type
is
unknown
, the
Simple Type Definition
defining the datatype will be incompletely
instantiated, and the datatype itself will be
unknown
Similarly, any datatype defined using an
unknown
constraining facet
will be
unknown
. It is not possible to perform datatype validation
as defined here using
unknown
datatypes.
Note:
The preceding paragraph does not forbid implementations from attempting
to make use of such partial information as they have about
unknown
datatypes. But the exploitation of such partial knowledge is not
datatype validity checking as defined here and is to be distinguished
from it in the implementation's documentation and interface.
4.3.1 length
[Definition:]
length
is the number
of
units of length
, where
units of length
varies depending on the type that is being
derived
from.
The value of
length
must
be a
nonNegativeInteger
For
string
and datatypes
derived
from
string
length
is measured in units of
character
s as defined in
[XML]
For
anyURI
length
is measured in units of
characters (as for
string
).
For
hexBinary
and
base64Binary
and datatypes
derived
from them,
length
is measured in octets (8 bits) of binary data.
For datatypes
constructed
by
list
length
is measured in number of list items.
Note:
For
string
and datatypes
derived
from
string
length
will not always coincide with "string length" as perceived
by some users or with the number of storage units in some digital representation.
Therefore, care should be taken when specifying a value for
length
and in attempting to infer storage requirements from a given value for
length
length
provides for:
Constraining a
value space
to values with a specific number of
units of length
where
units of length
varies depending on
{base type definition}
Example
The following is the definition of a
user-defined
datatype to represent product codes which must be
exactly 8 characters in length. By fixing the value of the
length
facet we ensure that types derived from productCode can
change or set the values of other facets, such as
pattern
, but
cannot change the length.
4.3.1.1 The length Schema Component
Schema Component:
length
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
An xs:nonNegativeInteger value. Required.
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
length
other than
{value}
Note:
The
{fixed}
property is defined for
parallelism with other facets and for
compatibility
with version 1.0
of this specification. But it is a consequence of
length valid restriction (§4.3.1.4)
that the value of
the
length
facet cannot be changed, regardless of
whether
{fixed}
is
true
or
false
4.3.1.2 XML Representation of length Schema Components
The XML representation for a
length
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
length
Element Information Item
boolean
: false
id =
ID
value
nonNegativeInteger
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
length
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.1.3 length Validation Rules
Validation Rule: Length Valid
A value in a
value space
is facet-valid with
respect to
length
if and only if:
if the
{variety}
is
atomic
then
1.1
if
{primitive type definition}
is
string
or
anyURI
, then the length of the value,
as measured in
character
must
be equal to
{value}
1.2
if
{primitive type definition}
is
hexBinary
or
base64Binary
, then the length of
the value, as measured in octets of the binary data,
must
be
equal to
{value}
1.3
if
{primitive type definition}
is
QName
or
NOTATION
, then any
{value}
is facet-valid.
if the
{variety}
is
list
then the length of the value, as measured in list items,
must
be
equal to
{value}
The use of
length
on
QName
NOTATION
, and datatypes
derived
from them
is deprecated. Future versions of this
specification may remove this facet for these datatypes.
4.3.1.4 Constraints on length Schema Components
Schema Component Constraint: length and minLength or maxLength
If
length
is a member of
{facets}
then
It is an error for
minLength
to be a member of
{facets}
unless
1.1
the
{value}
of
minLength
<= the
{value}
of
length
and
1.2
there is some
type definition from which this one is derived by
one or more
restriction
steps in which
minLength
has the same
{value}
and
length
is not specified.
It is an error for
maxLength
to be a member of
{facets}
unless
2.1
the
{value}
of
length
<= the
{value}
of
maxLength
and
2.2
there is some
type definition from which this one is derived by
one or more restriction steps in which
maxLength
has the same
{value}
and
length
is not specified.
Schema Component Constraint: length valid restriction
It is an
error
if
length
is among the members of
{facets}
of
{base type definition}
and
{value}
is
not equal to the
{value}
of the parent
length
4.3.2 minLength
[Definition:]
minLength
is
the minimum number of
units of length
, where
units of length
varies depending on the type that is being
derived
from.
The value of
minLength
must
be a
nonNegativeInteger
For
string
and datatypes
derived
from
string
minLength
is measured in units of
character
s as defined in
[XML]
For
hexBinary
and
base64Binary
and datatypes
derived
from them,
minLength
is measured in octets (8 bits) of binary data.
For datatypes
constructed
by
list
minLength
is measured in number of list items.
Note:
For
string
and datatypes
derived
from
string
minLength
will not always coincide with "string length" as perceived
by some users or with the number of storage units in some digital representation.
Therefore, care should be taken when specifying a value for
minLength
and in attempting to infer storage requirements from a given value for
minLength
minLength
provides for:
Constraining a
value space
to values with at least a specific number of
units of length
where
units of length
varies depending on
{base type definition}
Example
The following is the definition of a
user-defined
datatype which requires strings to have at least one character (i.e.,
the empty string is not in the
value space
of this datatype).
4.3.2.1 The minLength Schema Component
Schema Component:
minLength
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
An xs:nonNegativeInteger value. Required.
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
minLength
other than
{value}
4.3.2.2 XML Representation of minLength Schema Component
The XML representation for a
minLength
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
minLength
Element Information Item
boolean
: false
id =
ID
value
nonNegativeInteger
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
minLength
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.2.3 minLength Validation Rules
Validation Rule: minLength Valid
A value in a
value space
is facet-valid with
respect to
minLength
, determined as follows:
if the
{variety}
is
atomic
then
1.1
if
{primitive type definition}
is
string
or
anyURI
, then the
length of the value, as measured in
character
must
be greater than or equal to
{value}
1.2
if
{primitive type definition}
is
hexBinary
or
base64Binary
, then the
length of the value, as measured in octets of the binary data,
must
be greater than or equal to
{value}
1.3
if
{primitive type definition}
is
QName
or
NOTATION
, then
any
{value}
is facet-valid.
if the
{variety}
is
list
then the length of the value, as measured
in list items,
must
be greater than or equal
to
{value}
The use of
minLength
on
QName
NOTATION
, and datatypes
derived
from them
is deprecated. Future versions of this
specification may remove this facet for these datatypes.
4.3.2.4 Constraints on minLength Schema Components
Schema Component Constraint: minLength <= maxLength
If both
minLength
and
maxLength
are members of
{facets}
, then the
{value}
of
minLength
must
be less than or equal to the
{value}
of
maxLength
Schema Component Constraint: minLength valid restriction
It is an
error
if
minLength
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than the
{value}
of the parent
minLength
4.3.3 maxLength
[Definition:]
maxLength
is
the maximum number of
units of length
, where
units of length
varies
depending on the type that is being
derived
from.
The value of
maxLength
must
be a
nonNegativeInteger
For
string
and datatypes
derived
from
string
maxLength
is measured in units of
character
s as defined in
[XML]
For
hexBinary
and
base64Binary
and datatypes
derived
from them,
maxLength
is measured in octets (8 bits) of binary data.
For datatypes
constructed
by
list
maxLength
is measured in number of list items.
Note:
For
string
and datatypes
derived
from
string
maxLength
will not always coincide with "string length" as perceived
by some users or with the number of storage units in some digital representation.
Therefore, care should be taken when specifying a value for
maxLength
and in attempting to infer storage requirements from a given value for
maxLength
maxLength
provides for:
Constraining a
value space
to values with at most a specific number of
units of length
where
units of length
varies depending on
{base type definition}
Example
The following is the definition of a
user-defined
datatype which might be used to accept form input with an upper limit
to the number of characters that are acceptable.
4.3.3.1 The maxLength Schema Component
Schema Component:
maxLength
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
An xs:nonNegativeInteger value. Required.
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
maxLength
other than
{value}
4.3.3.2 XML Representation of maxLength Schema Components
The XML representation for a
maxLength
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
maxLength
Element Information Item
boolean
: false
id =
ID
value
nonNegativeInteger
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
maxLength
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.3.3 maxLength Validation Rules
Validation Rule: maxLength Valid
A value in a
value space
is facet-valid with
respect to
maxLength
, determined as follows:
if the
{variety}
is
atomic
then
1.1
if
{primitive type definition}
is
string
or
anyURI
, then the
length of the value, as measured in
character
must
be less than or equal to
{value}
1.2
if
{primitive type definition}
is
hexBinary
or
base64Binary
, then the
length of the value, as measured in octets of the binary data,
must
be less than or equal to
{value}
1.3
if
{primitive type definition}
is
QName
or
NOTATION
, then
any
{value}
is facet-valid.
if the
{variety}
is
list
then the length of the value, as measured
in list items,
must
be less than or equal to
{value}
The use of
maxLength
on
QName
NOTATION
, and datatypes
derived
from them
is deprecated. Future versions of this
specification may remove this facet for these datatypes.
4.3.3.4 Constraints on maxLength Schema Components
Schema Component Constraint: maxLength valid restriction
It is an
error
if
maxLength
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than the
{value}
of the parent
maxLength
4.3.4 pattern
[Definition:]
pattern
is a constraint on the
value space
of a datatype which is achieved by
constraining the
lexical space
to
literals
which match
each
member of a set of
regular
expressions
The value of
pattern
must
be a set of
regular expressions
Note:
An XML
containing more than one
element gives
rise to a single
regular expression
in the set; this
regular expression
is an "or" of
the
regular expressions
that
are the content of the
elements.
pattern
provides for:
Constraining a
value space
to values that are denoted by
literals
which match
each of a set of
regular expressions
Example
The following is the definition of a
user-defined
datatype which is a better representation of postal codes in the
United States, by limiting strings to those which are matched by
a specific
regular expression
4.3.4.1 The pattern Schema Component
Schema Component:
pattern
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
A non-empty set of
regular expressions
4.3.4.2 XML Representation of pattern Schema Components
The XML representation for a
pattern
schema
component is
one or more
element information items. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
pattern
Element Information Item
ID
value
string
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
pattern
Schema Component
Property
Representation
{value}
[Definition:]
Let
be a regular
expression given by
the appropriate
case
among the following:
If
there is only one
among the
[children]
of a
then
the
actual value
of its
value
[attribute]
otherwise
the concatenation of the
actual values
of
all the
[children]
's
value
[attributes]
, in order,
separated by '
', so forming a single regular expression with multiple
branches
The value is then given by
the appropriate
case
among the following:
If
the
{base type definition}
of the
owner
has a
pattern
facet among its
{facets}
then
the union of that
pattern
facet's
{value}
and {
otherwise
just {
{annotations}
The
annotation mapping
of the set containing all of the
elements among the
[children]
of the
element information item,
as defined in section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
Note:
The
{value}
property
will only have more than one member when
facet-based restriction
involves
pattern
facet at more than one step in a
type derivation. During validation, lexical forms will be
checked against every member of the resulting
{value}
, effectively
creating a conjunction of patterns.
In summary,
pattern
facets specified on the
same
step in a type
derivation are
OR
ed together, while
pattern
facets specified on
different
steps of a type derivation
are
AND
ed together.
Thus, to impose two
pattern
constraints simultaneously,
schema authors may either write a single
pattern
which
expresses the intersection of the two
pattern
s they wish to
impose, or define each
pattern
on a separate type derivation
step.
4.3.4.3 Constraints on XML Representation of pattern
Schema Representation Constraint: Pattern value
The
actual value
of the
value
[attribute]
must be a
regular expression
as
defined in
Regular Expressions (§G)
4.3.4.4 pattern Validation Rules
Validation Rule: pattern valid
literal
in a
lexical space
is pattern-valid (or: facet-valid with
respect to
pattern
if and only if
for each
regular expression
in its
{value}
the
literal
is among the set of character sequences denoted by
the
regular expression
Note:
As noted in
Datatype (§2.1)
certain uses of the
pattern
facet may
eliminate from the lexical space the canonical forms of some values
in the value space; this can be inconvenient for applications
which write out the canonical form of a value and rely on
being able to read it in again as a legal lexical form.
This specification provides no recourse in such situations;
applications are free to deal with it as they see fit.
Caution is advised.
4.3.4.5 Constraints on pattern Schema Components
Schema Component Constraint: Valid restriction of pattern
It is an
error
if there is any member of
the
{value}
of the
pattern
facet on the
{base type definition}
which is not also a member of the
{value}
Note:
For components constructed from XML representations in schema documents,
the satisfaction of this constraint is a consequence of the XML mapping rules:
any pattern imposed by a simple type definition
will always
also be imposed by any type derived from
by
facet-based restriction
This constraint ensures that components constructed by other means
(so-called "born-binary" components) similarly preserve
pattern
facets across
facet-based restriction
4.3.5 enumeration
[Definition:]
enumeration
constrains the
value space
to a specified set of values.
enumeration
does not impose an order relation on the
value space
it creates; the value of the
ordered
property of the
derived
datatype remains that of the datatype from which it is
derived
enumeration
provides for:
Constraining a
value space
to a specified set of values.
Example
The following example is a
Simple Type Definition
for a
user-defined
datatype which limits the values
of dates to the three US holidays enumerated. This
Simple Type Definition
would appear in a schema authored by an "end-user" and
shows how to define a datatype by enumerating the values in its
value space
. The enumerated values must be
type-valid
literals
for the
base type
4.3.5.1 The enumeration Schema Component
Schema Component:
enumeration
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
A set of values from the
value space
of the
{base type definition}
4.3.5.2 XML Representation of enumeration Schema Components
The XML representation for an
enumeration
schema
component is
one or more
element information items. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
enumeration
Element Information Item
ID
value
anySimpleType
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
enumeration
Schema Component
Property
Representation
{value}
The appropriate
case
among the following:
If
there is only one
among the
[children]
of a
then
a set with one member, the
actual value
of its
value
[attribute]
interpreted as an instance of
the
{base type definition}
otherwise
a set of the
actual values
of all the
[children]
's
value
[attributes]
, interpreted as instances of
the
{base type definition}
Note:
The
value
[attribute]
is declared as having
type
anySimpleType
, but the
{value}
property of the
enumeration
facet
must
be a member of the
{base type definition}
So in mapping from the XML representation
to the
enumeration
component, the
actual value
is
identified by using the
lexical mapping
of the
{base type definition}
{annotations}
A (possibly empty) sequence of
Annotation
components, one for each
among the
[children]
of the
s among the
[children]
of a
, in order.
4.3.5.3 Constraints on XML Representation of enumeration
Schema Representation Constraint: Enumeration value
The
normalized value
of the
value
[attribute]
must be
Datatype Valid (§4.1.4)
with respect to the
{base type definition}
of the
Simple Type Definition
corresponding to the
nearest
ancestor
element.
4.3.5.4 enumeration Validation Rules
Validation Rule: enumeration valid
A value in a
value space
is facet-valid with
respect to
enumeration
if and only if
the value is
equal or identical
to
one of the values specified in
{value}
Note:
As specified normatively elsewhere, for purposes of checking
enumerations, no distinction is made between an atomic value
and a list of length one containing
as its only item.
In this question, the behavior of this specification is thus
the same as the behavior specified by
[XQuery 1.0 and XPath 2.0 Functions and Operators]
and related specifications.
4.3.5.5 Constraints on enumeration Schema Components
Schema Component Constraint: enumeration valid restriction
It is an
error
if any member of
{value}
is not in the
value space
of
{base type definition}
4.3.6 whiteSpace
[Definition:]
whiteSpace
constrains the
value space
of types
derived
from
string
such that
the various behaviors
specified in
Attribute Value Normalization
in
[XML]
are realized. The value of
whiteSpace
must be one of {preserve, replace, collapse}.
preserve
No normalization is done, the value is not changed (this is the
behavior required by
[XML]
for element content)
replace
All occurrences of #x9 (tab), #xA (line feed) and #xD (carriage return)
are replaced with #x20 (space)
collapse
After the processing implied by
replace
, contiguous
sequences of #x20's are collapsed to a single #x20, and any #x20
at the start or end of the string is then removed.
Note:
The notation #xA used here (and elsewhere in this specification)
represents the Universal Character Set (UCS) code point
hexadecimal A
(line feed), which is denoted by
U+000A. This notation is to be distinguished from
, which is the XML
character reference
to that same UCS
code point.
whiteSpace
is applicable to all
atomic
and
list
datatypes. For all
atomic
datatypes other than
string
(and types
derived
by
facet-based restriction
from it) the value of
whiteSpace
is
collapse
and cannot be changed by a schema author; for
string
the value of
whiteSpace
is
preserve
; for any type
derived
by
facet-based restriction
from
string
the value of
whiteSpace
can
be any of the three legal values
(as long as the value is at least as restrictive as
the value of the
base type
; see
Constraints on whiteSpace Schema Components (§4.3.6.4)
). For all datatypes
constructed
by
list
the
value of
whiteSpace
is
collapse
and cannot
be changed by a schema author. For all datatypes
constructed
by
union
whiteSpace
does not apply directly; however, the
normalization behavior of
union
types is controlled by
the value of
whiteSpace
on that one of the
basic members
against which the
union
is successfully validated.
Note:
For more information on
whiteSpace
, see the
discussion on white space normalization in
Schema Component Details
in
[XSD 1.1 Part 1: Structures]
whiteSpace
provides for:
Constraining a
value space
according to
the white space normalization rules.
Example
The following example is the
Simple Type Definition
for
the
built-in
token
datatype.
Note:
The values "
replace
" and
collapse
" may appear to provide a
convenient way to "unwrap" text (i.e. undo the effects of
pretty-printing and word-wrapping). In some cases, especially
highly constrained data consisting of lists of artificial tokens
such as part numbers or other identifiers, this appearance is
correct. For natural-language data, however, the whitespace
processing prescribed for these values is not only unreliable but
will systematically remove the information needed to perform
unwrapping correctly. For Asian scripts, for example, a correct
unwrapping process will replace line boundaries not with blanks but
with zero-width separators or nothing. In consequence, it is
normally unwise to use these values for natural-language data, or
for any data other than lists of highly constrained tokens.
4.3.6.1 The whiteSpace Schema Component
Schema Component:
whiteSpace
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
One of {
preserve
replace
collapse
}. Required.
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
whiteSpace
other than
{value}
4.3.6.2 XML Representation of whiteSpace Schema Components
The XML representation for a
whiteSpace
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
whiteSpace
Element Information Item
boolean
: false
id =
ID
value
= (
collapse
preserve
replace
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
whiteSpace
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.6.3 whiteSpace Validation Rules
Note:
There are no
Validation Rule
s associated
with
whiteSpace
For more information, see the
discussion on white space normalization in
Schema Component Details
in
[XSD 1.1 Part 1: Structures]
, in particular
the section
3.1.4
White Space Normalization during Validation
4.3.6.4 Constraints on whiteSpace Schema Components
Schema Component Constraint: whiteSpace valid restriction
It is an
error
if
whiteSpace
is among the members of
{facets}
of
{base type definition}
and any of the following conditions is
true:
{value}
is
replace
or
preserve
and the
{value}
of the parent
whiteSpace
is
collapse
{value}
is
preserve
and the
{value}
of the parent
whiteSpace
is
replace
Note:
In order of increasing restrictiveness, the
legal values for the
whiteSpace
facet are
preserve
collapse
, and
replace
. The more restrictive keywords
are more restrictive not in the sense
of accepting progressively fewer instance documents but
in the sense that each corresponds to a progressively smaller,
more tightly restricted value space.
4.3.7 maxInclusive
[Definition:]
maxInclusive is the inclusive upper bound of the
value space
for a datatype with the
ordered
property. The value of
maxInclusive
must
be equal to some value
in the
value space
of the
base type
maxInclusive
provides for:
Constraining a
value space
to values with a
specific inclusive upper
bound.
Example
The following is the definition of a
user-defined
datatype which limits values to integers less than or equal to
100, using
maxInclusive
4.3.7.1 The maxInclusive Schema Component
Schema Component:
maxInclusive
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
Required.
A value from the
value space
of the
{base type definition}
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
maxInclusive
other than
{value}
4.3.7.2 XML Representation of maxInclusive Schema Components
The XML representation for a
maxInclusive
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
maxInclusive
Element Information Item
boolean
: false
id =
ID
value
anySimpleType
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
{value}
must
be equal to some value
in the
value space
of
{base type definition}
maxInclusive
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.7.3 maxInclusive Validation Rules
Validation Rule: maxInclusive Valid
A value
in an
ordered
value space
is facet-valid with respect to
maxInclusive
if and only if
the value is less than or equal to
{value}
according to the
datatype's order relation.
4.3.7.4 Constraints on maxInclusive Schema Components
Schema Component Constraint: minInclusive <= maxInclusive
It is an
error
for the value specified for
minInclusive
to be greater than the value
specified for
maxInclusive
for the same datatype.
Schema Component Constraint: maxInclusive valid restriction
It is an
error
if any of the following conditions
is true:
maxInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than the
{value}
of
that
maxInclusive
maxExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than or equal to the
{value}
of
that
maxExclusive
minInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than the
{value}
of
that
minInclusive
minExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than or equal to the
{value}
of
that
minExclusive
4.3.8 maxExclusive
[Definition:]
maxExclusive
is the exclusive upper bound of the
value space
for a datatype with the
ordered
property. The value of
maxExclusive
must
be equal to some value
in the
value space
of the
base type
or
be equal to
{value}
in
{base type definition}
maxExclusive
provides for:
Constraining a
value space
to values with a
specific exclusive upper
bound.
Example
The following is the definition of a
user-defined
datatype which limits values to integers less than or equal to
100, using
maxExclusive
Note that the
value space
of this datatype is identical to
the previous one (named 'one-hundred-or-less').
4.3.8.1 The maxExclusive Schema Component
Schema Component:
maxExclusive
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
Required.
A value from the
value space
of the
{base type definition}
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
maxExclusive
other than
{value}
4.3.8.2 XML Representation of maxExclusive Schema Components
The XML representation for a
maxExclusive
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
maxExclusive
Element Information Item
boolean
: false
id =
ID
value
anySimpleType
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
{value}
must
be equal to some value
in the
value space
of
{base type definition}
maxExclusive
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.8.3 maxExclusive Validation Rules
Validation Rule: maxExclusive Valid
A value
in an
ordered
value space
is facet-valid with respect to
maxExclusive
if and only if
the value is less than
{value}
, according to the
datatype's order relation.
4.3.8.4 Constraints on maxExclusive Schema Components
Schema Component Constraint: maxInclusive and maxExclusive
It is an
error
for both
maxInclusive
and
maxExclusive
to be specified in the same derivation step of a
Simple Type Definition
Schema Component Constraint: minExclusive <= maxExclusive
It is an
error
for the value specified for
minExclusive
to be greater than the value
specified for
maxExclusive
for the same datatype.
Schema Component Constraint: maxExclusive valid restriction
It is an
error
if any of the following conditions
is true:
maxExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than the
{value}
of
that
maxExclusive
maxInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than the
{value}
of
that
maxInclusive
minInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than or equal to the
{value}
of
that
minInclusive
minExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than or equal to the
{value}
of
that
minExclusive
4.3.9 minExclusive
[Definition:]
minExclusive
is the exclusive lower bound of the
value space
for a datatype with the
ordered
property. The value of
minExclusive
must
be equal to some value
in the
value space
of the
base type
or
be equal to
{value}
in
{base type definition}
minExclusive
provides for:
Constraining a
value space
to values with a
specific exclusive lower bound.
Example
The following is the definition of a
user-defined
datatype which limits values to integers greater than or equal to
100, using
minExclusive
Note that the
value space
of this datatype is identical to the
following
one (named 'one-hundred-or-more').
4.3.9.1 The minExclusive Schema Component
Schema Component:
minExclusive
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
Required.
A value from the
value space
of the
{base type definition}
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
minExclusive
other than
{value}
4.3.9.2 XML Representation of minExclusive Schema Components
The XML representation for a
minExclusive
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
minExclusive
Element Information Item
boolean
: false
id =
ID
value
anySimpleType
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
{value}
must
be equal to some value
in the
value space
of
{base type definition}
minExclusive
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.9.3 minExclusive Validation Rules
Validation Rule: minExclusive Valid
A value in an
ordered
value space
is facet-valid with respect to
minExclusive
if and only if
the value is greater than
{value}
, according to the
datatype's order relation.
4.3.9.4 Constraints on minExclusive Schema Components
Schema Component Constraint: minInclusive and minExclusive
It is an
error
for both
minInclusive
and
minExclusive
to be specified in the same derivation step of a
Simple Type Definition
Schema Component Constraint: minExclusive < maxInclusive
It is an
error
for the value specified for
minExclusive
to be greater than or equal to the value
specified for
maxInclusive
for the same datatype.
Schema Component Constraint: minExclusive valid restriction
It is an
error
if any of the following conditions is true:
minExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than the
{value}
of
that
minExclusive
minInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than the
{value}
of
that
minInclusive
maxInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than or equal to the
{value}
of that
maxInclusive
maxExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than or equal to the
{value}
of
that
maxExclusive
4.3.10 minInclusive
[Definition:]
minInclusive
is the inclusive lower bound of the
value space
for a datatype with the
ordered
property. The value of
minInclusive
must
be equal to some value
in the
value space
of the
base type
minInclusive
provides for:
Constraining a
value space
to values with a
specific inclusive lower
bound.
Example
The following is the definition of a
user-defined
datatype which limits values to integers greater than or equal to
100, using
minInclusive
4.3.10.1 The minInclusive Schema Component
Schema Component:
minInclusive
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
Required.
A value from the
value space
of the
{base type definition}
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
cannot specify a
value for
minInclusive
other than
{value}
4.3.10.2 XML Representation of minInclusive Schema Components
The XML representation for a
minInclusive
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
minInclusive
Element Information Item
boolean
: false
id =
ID
value
anySimpleType
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
{value}
must
be equal to some value
in the
value space
of
{base type definition}
minInclusive
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.10.3 minInclusive Validation Rules
Validation Rule: minInclusive Valid
A value in an
ordered
value space
is facet-valid with respect to
minInclusive
if and only if
the value is greater than or equal to
{value}
, according to the
datatype's order relation.
4.3.10.4 Constraints on minInclusive Schema Components
Schema Component Constraint: minInclusive < maxExclusive
It is an
error
for the value specified for
minInclusive
to be greater than or equal to the value
specified for
maxExclusive
for the same datatype.
Schema Component Constraint: minInclusive valid restriction
It is an
error
if any of the following conditions
is true:
minInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than the
{value}
of
that
minInclusive
maxInclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater the
{value}
of
that
maxInclusive
minExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
less than or equal to the
{value}
of
that
minExclusive
maxExclusive
is among the members of
{facets}
of
{base type definition}
and
{value}
is
greater than or equal to the
{value}
of
that
maxExclusive
4.3.11 totalDigits
[Definition:]
totalDigits
restricts the magnitude and
arithmetic
precision
of values in the
value spaces
of
decimal
and datatypes derived from it.
For
decimal
if the
{value}
of
totalDigits
is
, the effect is to require that values be equal to
/ 10
, for some
integers
and
, with
| < 10
and
0 ≤
This has as a consequence that the values are expressible
using at most
digits in decimal notation.
The
{value}
of
totalDigits
must
be
positiveInteger
The term 'totalDigits' is chosen to reflect the fact that
it restricts the
value space
to those values that
can be represented lexically using at most
totalDigits
digits in
decimal notation, or at most
totalDigits
digits
for the coefficient, in scientific notation.
Note that it does not restrict
the
lexical space
directly; a lexical
representation that adds
non-significant
leading or trailing
zero digits is still permitted.
It also has no effect on the values
NaN, INF, and -INF.
4.3.11.1 The totalDigits Schema Component
Schema Component:
totalDigits
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
An xs:positiveInteger value. Required.
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then types for which
the current type is the
{base type definition}
must
not specify a
value for
totalDigits
other than
{value}
4.3.11.2 XML Representation of totalDigits Schema Components
The XML representation for a
totalDigits
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
totalDigits
Element Information Item
boolean
: false
id =
ID
value
positiveInteger
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
totalDigits
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.11.3 totalDigits Validation Rules
Validation Rule: totalDigits Valid
A value
is facet-valid with respect to a
totalDigits
facet with
{value}
of
if and only
if
is a
decimal
value equal to
/ 10
for some
integers
and
, with
| < 10
and
0 ≤
4.3.11.4 Constraints on totalDigits Schema Components
Schema Component Constraint: totalDigits valid restriction
It is an
error
if the
owner
's
{base type definition}
has a
totalDigits
facet
among its
{facets}
and
{value}
is
greater than the
{value}
of
that
totalDigits
facet.
4.3.12 fractionDigits
[Definition:]
fractionDigits
places an upper limit on the
arithmetic precision
of
decimal
values: if the
{value}
of
fractionDigits
, then the value space is
restricted to values equal to
/ 10
for some integers
and
and
0 ≤
The value of
fractionDigits
must
be a
nonNegativeInteger
The term
fractionDigits
is chosen to reflect the fact that it
restricts the
value space
to those values that can be
represented lexically
in decimal notation using at most
fractionDigits
to the right of the decimal point. Note that it does not restrict
the
lexical space
directly; a
lexical representation that adds
non-significant
leading or trailing zero digits is still permitted.
Example
The following is the definition of a
user-defined
datatype which could be used to represent the magnitude
of a person's body temperature on the Celsius scale.
This definition would appear in a schema authored by an "end-user"
and shows how to define a datatype by specifying facet values which
constrain the range of the
base type
4.3.12.1 The fractionDigits Schema Component
Schema Component:
fractionDigits
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
An xs:nonNegativeInteger value. Required.
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then
types for which the current type is the
{base type definition}
must
not
specify a value for
fractionDigits
other
than
{value}
4.3.12.2 XML Representation of fractionDigits Schema Components
The XML representation for a
fractionDigits
schema
component is a
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
fractionDigits
Element Information Item
boolean
: false
id =
ID
value
nonNegativeInteger
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
fractionDigits
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.12.3 fractionDigits Validation Rules
Validation Rule: fractionDigits Valid
A value
is facet-valid with
respect to
fractionDigits
if and only if
that value is equal to
/ 10
for integer
and
, with
0 ≤
{value}
4.3.12.4 Constraints on fractionDigits Schema Components
Schema Component Constraint: fractionDigits less than or equal to totalDigits
It is an
error
for
the
{value}
of
fractionDigits
to be greater than
that of
totalDigits
Schema Component Constraint: fractionDigits valid restriction
It is an
error
if
fractionDigits
is among the members of
{facets}
of
{base type definition}
and
{value}
is greater than the
{value}
of
that
fractionDigits
4.3.13 Assertions
[Definition:]
Assertions
constrain the
value space
by requiring the values to satisfy specified XPath
[XPath 2.0]
) expressions. The value of
the
assertions
facet
is a sequence of
Assertion
components as defined in
[XSD 1.1 Part 1: Structures]
Example
The following is the definition of a
user-defined
datatype which allows all integers but 0 by using an assertion to
disallow the value 0.
Example
The following example defines the datatype "triple",
whose
value space
is the set of integers evenly divisible by
three.
The same datatype can be defined without the use of assertions,
but the pattern necessary to represent the set of triples is
long and error-prone:
The assertion used in the first version of "triple" is
likely to be clearer for many readers of the schema document.
4.3.13.1 The assertions Schema Component
Schema Component:
assertions
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
A sequence of
Assertion
components.
4.3.13.2 XML Representation of assertions Schema Components
The XML representation for an
assertions
schema component is
one or more
element information items. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
assertion
Element Information Item
ID
test
an XPath expression
xpathDefaultNamespace =
anyURI
| (
##defaultNamespace
##targetNamespace
##local
))
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
assertions
Schema Component
Property
Representation
{value}
A sequence whose members are
Assertion
s drawn from the following sources,
in order:
If the
{base type definition}
of the
owner
has an
assertions
facet among its
{facets}
, then the
Assertion
s which appear in the
{value}
of that
assertions
facet.
Assertion
s corresponding to the
element
information items among the
[children]
of
if any, in document order. For
details of the construction of the
Assertion
components, see
section 3.13.2
of
[XSD 1.1 Part 1: Structures]
{annotations}
The empty sequence.
Note:
Annotations specified within an
element are captured by
the individual
Assertion
component to which it maps.
4.3.13.3 Assertions Validation Rules
The following rule refers to
"the nearest built-in" datatype
and to the "XDM representation" of a value
under a datatype.
[Definition:]
For
any datatype
, the
nearest built-in datatype
to
is the first
built-in
datatype encountered in following
the chain of links connecting each datatype to its
base type
. If
is a
built-in
datatype, then the
nearest built-in datatype of
is
itself; otherwise,
it is the nearest built-in datatype of
's
base type
[Definition:]
For
any value
and any datatype
, the
XDM representation of
under
is
defined recursively as follows. Call the XDM representation
. Then
If
xs:anySimpleType
or
xs:anyAtomicType
then
is
and the
dynamic
type
of
is
xs:untypedAtomic
If
{variety}
atomic
then
let
T2
be the
nearest built-in datatype
to
If
is a member of the
value space
of
T2
, then
is
and the
dynamic type
of
is
T2
Otherwise (i.e. if
is not a member of the
value space
of
T2
),
is the
XDM representation
of
under
T2
{base type definition}
If
{variety}
list
then
is a sequence of atomic values, each atomic value
being the
XDM representation
of the corresponding
item in the list
under
{item type definition}
If
{variety}
union
then
is the
XDM representation
of
under the
active basic member
of
when validated against
If there is no
active basic member
then
has no
XDM representation
under
Note:
If the
{item type definition}
of a
list
is a
union
, or the
active basic member
is
list
, then several steps may be necessary before the
atomic
datatype which serves as the
dynamic
type
of
is found.
Because the
{item type definition}
of a
list
is required to be an
atomic
or
union
datatype,
and the
active basic member
of a
union
which accepts the value
is by definition not a
union
, the recursive rule given above is guaranteed to
terminate in a sequence of one or more
atomic
values,
each belonging to an
atomic
datatype.
Validation Rule: Assertions Valid
A value
is facet-valid with respect to an
assertions
facet
belonging to a simple type
if and only if the {test}
property of each
Assertion
in its
{value}
evaluates to
true
under the
conditions laid out below, without raising any
dynamic error
or
type error
Evaluation of {test} is performed as defined in
[XPath 2.0]
, with the following conditions:
The XPath expression {test} is evaluated,
following the rules given in
XPath Evaluation
of
[XSD 1.1 Part 1: Structures]
with the
following modifications.
1.1
The
in-scope variables
in the
static context
is a set with a single member. The
expanded QName
of that member has no namespace
URI and
has
value
' as the local
name. The (static)
type
of the member is
anyAtomicType*
Note:
The XDM type label
anyAtomicType*
simply says
that for static typing purposes the variable
$value
will have a value consisting of a sequence of zero or more
atomic values.
1.2
There is no
context
item
for the evaluation of the XPath expression.
Note:
In the terminology of
[XPath 2.0]
, the
context
item
is "undefined".
Note:
As a consequence the expression '
',
or any implicit or
explicit reference to the context item, will raise a
dynamic error, which will cause the assertion to be treated as false.
If an error is detected statically, then the assertion
violates the schema component constraint
XPath Valid
and causes an error to be flagged in the schema.
The variable "
$value
" can be
used to refer to the value being checked.
1.3
There is likewise no value for the
context
size
and the
context
position
in the
dynamic context
used for evaluation of the assertion.
1.4
The
variable values
in the
dynamic context
is a set with a single member. The
expanded QName
of that member has no
namespace URI
and '
value
' as the local
name. The
value
of the member is
the
XDM representation
of
under
1.5
If
has no
XDM representation
under
then the XPath expression cannot usefully be evaluated,
and
is not facet-valid against the
assertions
facet of
The evaluation result is converted to either
true
or
false
as if by a call to the XPath
fn:boolean
function.
4.3.13.4 Constraints on assertions Schema Components
Schema Component Constraint: Valid restriction of assertions
The
{value}
of the
assertions
facet
on the
{base type definition}
must
be a prefix of
the
{value}
Note:
For components constructed from XML representations in schema documents,
the satisfaction of this constraint is a consequence of the XML mapping rules:
any assertion imposed by a simple type definition
will always
also be imposed by any type derived from
by
facet-based restriction
This constraint ensures that components constructed by other means
(so-called "born-binary" components) similarly preserve
assertions
facets across
facet-based restriction
4.3.14 explicitTimezone
[Definition:]
explicitTimezone
is a
three-valued facet which can can be used to
require or prohibit the time zone offset in date/time datatypes.
Example
The following
user-defined
datatype accepts only
date
values without a time zone offset,
using the
explicitTimezone
facet.
The same effect could also be achieved using the
pattern
facet, as shown below,
but it is somewhat less clear what is going on in
this derivation, and it is better practice to use
the more straightforward
explicitTimezone
for this purpose.
4.3.14.1 The explicitTimezone Schema Component
Schema Component:
explicitTimezone
, a kind of
Constraining Facet
{annotations}
A sequence of
Annotation
components.
{value}
One of {
required
prohibited
optional
}. Required.
{fixed}
An xs:boolean value. Required.
If
{fixed}
is
true
, then datatypes for which
the current type is the
{base type definition}
cannot specify a
value for
explicitTimezone
other than
{value}
Note:
It is a consequence of
timezone valid restriction (§4.3.14.4)
that the value of
the
explicitTimezone
facet cannot be changed unless that
value is
optional
, regardless of
whether
{fixed}
is
true
or
false
. Accordingly,
{fixed}
is relevant only when
{value}
is
optional
4.3.14.2 XML Representation of explicitTimezone Schema Components
The XML representation for an
explicitTimezone
schema
component is an
element information item. The
correspondences between the properties of the information item and
properties of the component are as follows:
XML Representation Summary
explicitTimezone
Element Information Item
boolean
: false
id =
ID
value
NCName
{any attributes with non-schema namespace . . .}
Content:
annotation
?)
explicitTimezone
Schema Component
Property
Representation
{value}
The
actual value
of the
value
[attribute]
{fixed}
The
actual value
of the
fixed
[attribute]
, if present, otherwise
false
{annotations}
The
annotation mapping
of the
element, as defined in
section
XML Representation of Annotation Schema Components
of
[XSD 1.1 Part 1: Structures]
4.3.14.3 explicitTimezone Validation Rules
Validation Rule: explicitOffset Valid
dateTime
value
is facet-valid with respect to
explicitTimezone
if and only if
one
of the following is true
The
{value}
of the facet is
required
and
has a (non-
absent
value for the
timezoneOffset
property.
The
{value}
of the facet is
prohibited
and the value for the
timezoneOffset
property in
is
absent
The
{value}
of the facet is
optional
4.3.14.4 Constraints on explicitTimezone Schema Components
Schema Component Constraint: timezone valid restriction
If the
explicitTimezone
facet
on the
{base type definition}
has a
{value}
other than
optional
then
the
{value}
of the facet on the
restriction
must
be equal to the
{value}
on
the
{base type definition}
; otherwise
it is an
error
Note:
The effect of this rule is to allow datatypes with
explicitTimezone
value of
optional
to be
restricted by specifying a value of
required
or
prohibited
, and to forbid any other derivations
using this facet.
5 Conformance
XSD 1.1: Datatypes
is intended
to be usable in a variety of contexts.
In the usual case, it will embedded in a
host language
such as
[XSD 1.1 Part 1: Structures]
which refers to this specification normatively to define some part of
the host language. In some cases,
XSD 1.1: Datatypes
may
be implemented independently of any host language.
Certain aspects of the behavior of conforming
processors are described in this specification as
implementation-defined
or
implementation-dependent
[Definition:]
Something
which
may
vary among conforming implementations, but which
must
be specified by the implementor for each particular implementation,
is
implementation-defined
[Definition:]
Something
which
may
vary among conforming implementations, is not specified by
this or any W3C specification, and is not required to be specified
by the implementor for any particular implementation,
is
implementation-dependent
Anything described in this specification as
implementation-defined
or
implementation-dependent
may
be further constrained by the specifications
of a host language in which the datatypes and other material
specified here are used.
A list of implementation-defined and implementation-dependent
features can be found in
Implementation-defined and implementation-dependent features (normative) (§H)
5.1 Host Languages
When
XSD 1.1: Datatypes
is embedded in a host
language, the definition of conformance is specified by the
host language, not by this specification. That is, when this
specification is implemented in the context of an implementation
of a host language, the question of conformance to this
specification (separate from the host language) does not arise.
This specification imposes certain constraints on the
embedding of
XSD 1.1: Datatypes
by a host
language; these are indicated in the normative text by
the use of the verbs '
must
', etc.,
with the phrase "host language" as the subject
of the verb.
Note:
For convenience, the most important of these constraints
are noted here:
Host languages
should
specify that all of the datatypes described
here as built-ins are automatically available.
Host languages
may
specify that additional datatypes are also
made available automatically.
If user-defined datatypes are to be supported in the host language,
then the host language
must
specify how user-defined datatypes are
defined and made available for use.
In addition, host languages
must
require conforming
implementations of
the host language to obey all of the constraints and rules
specified here.
5.2 Independent implementations
[Definition:]
Implementations claiming
minimal conformance
to this specification
independent of any host language
must
do
all
of the following:
Support all the
built-in
datatypes defined in this specification.
Completely and correctly implement all of
the
constraints on schemas
defined in this specification.
Completely and correctly implement all of
the
Validation Rules
defined in this specification, when checking the
datatype validity of literals against datatypes.
Implementations claiming
schema-document-aware conformance
to this specification, independent of any host language
must
be
minimally conforming. In addition, they must do
all
of the following:
Accept simple type definitions in the form specified in
Datatype components (§4)
Completely and correctly implement all of
rules governing the XML representation of simple type definitions
specified in
Datatype components (§4)
Map the XML representations of simple type definitions to
simple type definition components as specified in the mapping
rules given in
Datatype components (§4)
Note:
The term
schema-document aware
is used here for
parallelism with the corresponding term in
[XSD 1.1 Part 1: Structures]
The reference to schema documents may be taken as referring
to the fact that schema-document-aware implementations accept
the XML representation of simple type definitions found in
XSD schema documents. It does
not
mean that
the simple type definitions must themselves be free-standing
XML documents, nor that they typically will be.
5.3 Conformance of data
Abstract representations of simple type definitions conform to this
specification if and only if they obey all of the
constraints on schemas
defined in this
specification.
XML representations of simple type definitions conform to this
specification if they obey all of the applicable rules
defined in this specification.
Note:
Because the conformance of the resulting simple type definition
component depends not only on the XML representation of a given
simple type definition, but on the properties of its
base type
, the conformance of an XML representation of a
simple type definition does not guarantee that, in the
context of other schema components, it will map to
a conforming component.
5.4 Partial Implementation of Infinite Datatypes
Some
primitive
datatypes defined in this specification have
infinite
value spaces
; no finite implementation can completely
handle all their possible values. For some such datatypes, minimum
implementation limits are specified below. For other infinite types
such as
string
hexBinary
, and
base64Binary
, no minimum implementation limits are
specified.
When this specification is used in the context of other languages
(as it is, for example, by
[XSD 1.1 Part 1: Structures]
), the
host language may specify other minimum implementation limits.
When presented with a literal or value exceeding the capacity of
its partial implementation of a datatype, a minimally conforming
implementation of this specification will sometimes be unable to
determine with certainty whether the value is datatype-valid or
not. Sometimes it will be unable to represent the value correctly
through its interface to any downstream application.
When either of these is so, a conforming processor
must
indicate
to the user and/or downstream application that it cannot process
the input data with assured correctness (much as it would indicate
if it ran out of memory). When the datatype validity of a value
or literal is uncertain because it exceeds the capacity of a
partial implementation, the literal or value
must not
be treated
as invalid, and the unsupported value
must not
be quietly changed
to a supported value.
This specification does not constrain the method used to indicate
that a literal or value in the input data has exceeded the
capacity of the implementation, or the form such indications take.
Minimally
conforming
processors
which set an application- or
implementation-defined
limit
on the size of the values supported
must
clearly document
that limit.
These are the partial-implementation
minimal conformance
requirements:
All
minimally conforming
processors
must
support
decimal
values whose absolute value can be expressed as
/ 10
, where
and
are nonnegative integers such that
< 10
16
and
≤ 16 (i.e., those expressible with sixteen total
digits).
All
minimally conforming
processors
must
support nonnegative
year
values
less than 10000 (i.e., those expressible with four
digits) in all datatypes
which use the seven-property model defined in
The Seven-property Model (§D.2.1)
and have a non-
absent
value for
year
(i.e.
dateTime
dateTimeStamp
date
gYearMonth
, and
gYear
).
All
minimally conforming
processors
must
support
second
values to
milliseconds (i.e. those expressible with three
fraction digits)
in all datatypes
which use the seven-property model defined in
The Seven-property Model (§D.2.1)
and have a non-
absent
value for
second
(i.e.
dateTime
dateTimeStamp
, and
time
).
All
minimally conforming
processors
must
support fractional-second
duration
values to
milliseconds (i.e. those expressible with three fraction digits).
All
minimally conforming
processors
must
support
duration
values with
months
values in the range −119999 to 119999
months (9999 years and 11 months) and
seconds
values in the range −31622400 to 31622400 seconds (one
leap-year).
A Schema for Schema Documents (Datatypes)
(normative)
The XML representation of the datatypes-relevant
part of the schema for schema documents is presented here
as a normative
part of the specification.
Independent copies of this material are
available in an undated (mutable) version at
and in a dated (immutable) version at
— the mutable version will be updated with future revisions of
this specification, and the immutable one will not.
Like any other
XML document, schema documents may carry XML and document type declarations. An
XML declaration and a document type declaration are provided here for convenience.
Since
this schema document describes the XML Schema language, the
targetNamespace
attribute on the
schema
element refers to the XML Schema namespace
itself.
Schema documents conforming to this specification may be in XML
1.0 or XML 1.1. Conforming implementations may accept input in
XML 1.0 or XML 1.1 or both. See
Dependencies on Other Specifications (§1.3)
Schema for Schema Documents (Datatypes)
]>
xml:lang="en"
targetNamespace="http://www.w3.org/2001/XMLSchema"
version="datatypes.xsd (rec-20120405)">
The schema corresponding to this document is normative,
with respect to the syntactic constraints it expresses in the
XML Schema language. The documentation (within 'documentation'
elements) below, is not normative, but rather highlights important
aspects of the W3C Recommendation of which this is a part.
See below (at the bottom of this document) for information about
the revision and namespace-versioning policy governing this
schema document.
A utility type, not for public use
#all or (possibly empty) subset of {restriction, extension, union, list}
A utility type, not for public use
Can be restricted to required or forbidden
Required at the top level
Forbidden when nested
An abstract element, representing facets in general.
The facets defined by this spec are substitutable for
this element, and implementation-defined facets should
also name this as a substitution-group head.
base attribute and simpleType child are mutually
exclusive, but one or other is required
itemType attribute and simpleType child are mutually
exclusive, but one or other is required
memberTypes attribute must be non-empty or there must be
at least one simpleType child
substitutionGroup="xs:facet">
substitutionGroup="xs:facet">
substitutionGroup="xs:facet">
substitutionGroup="xs:facet">
substitutionGroup="xs:facet">
substitutionGroup="xs:facet">
substitutionGroup="xs:facet">
substitutionGroup="xs:facet">
In keeping with the XML Schema WG's standard versioning policy,
this schema document will persist at the URI
At the date of issue it can also be found at the URI
The schema document at that URI may however change in the future,
in order to remain compatible with the latest version of XSD
and its namespace. In other words, if XSD or the XML Schema
namespace change, the version of this document at
the version at http://www.w3.org/2012/04/datatypes.xsd will not change.
Previous dated (and unchanging) versions of this schema document
include:
(XSD 1.1 Proposed Recommendation)
(XSD 1.1 Candidate Recommendation)
(XSD 1.1 Candidate Recommendation)
(XSD 1.0 Recommendation, Second Edition)
(XSD 1.0 Recommendation, First Edition)
B DTD for Datatype Definitions (non-normative)
The DTD for the datatypes-specific
aspects of schema documents is given below. Note there is
no
implication here that
schema
must
be
the root element of a document.
DTD for datatype definitions
"%pattern; | %enumeration; | %whiteSpace; | %length; |
%maxLength; | %minLength; | %assertion;
| %explicitTimezone;">
"value CDATA #REQUIRED
id ID #IMPLIED">
((%annotation;)?, (%restriction; | %list; | %union;))>
name %NCName; #IMPLIED
final %simpleDerivationSet; #IMPLIED
id ID #IMPLIED
%simpleTypeAttrs;>
(%restriction1; |
((%simpleType;)?,(%facet;)*)),
(%attrDecls;))>
base %QName; #IMPLIED
id ID #IMPLIED
%restrictionAttrs;>
itemType %QName; #IMPLIED
id ID #IMPLIED
%listAttrs;>
id ID #IMPLIED
memberTypes %QNames; #IMPLIED
%unionAttrs;>
%facetAttr;
%fixedAttr;
%maxExclusiveAttrs;>
%facetAttr;
%fixedAttr;
%minExclusiveAttrs;>
%facetAttr;
%fixedAttr;
%maxInclusiveAttrs;>
%facetAttr;
%fixedAttr;
%minInclusiveAttrs;>
%facetAttr;
%fixedAttr;
%totalDigitsAttrs;>
%facetAttr;
%fixedAttr;
%fractionDigitsAttrs;>
%facetAttr;
%fixedAttr;
%lengthAttrs;>
%facetAttr;
%fixedAttr;
%minLengthAttrs;>
%facetAttr;
%fixedAttr;
%maxLengthAttrs;>
%facetAttr;
%enumerationAttrs;>
%facetAttr;
%fixedAttr;
%whiteSpaceAttrs;>
%facetAttr;
%patternAttrs;>
%facetAttr;
%assertionAttrs;>
%facetAttr;
%explicitTimezoneAttrs;>
C Illustrative XML representations for the built-in simple type definitions
C.1 Illustrative XML representations for the built-in primitive type definitions
The following, although in the form of a
schema document, does not conform to the rules for schema documents
defined in this specification. It contains explicit XML
representations of the primitive datatypes which need not be declared
in a schema document, since they are automatically included in every
schema, and indeed must not be declared in a schema document, since it
is forbidden to try to derive types with
anyAtomicType
as the base type definition. It is included here as a form of
documentation.
The (not a) schema document for primitive built-in type definitions
name NMTOKEN #REQUIRED>
name NMTOKEN #REQUIRED
value CDATA #REQUIRED>
]>
xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified"
xml:lang="en"
targetNamespace="http://www.w3.org/2001/XMLSchema">
This document contains XML elements which look like
definitions for the primitive datatypes. These definitions are for
information only; the real built-in definitions are magic.
For each built-in datatype in this schema (both primitive and
derived) can be uniquely addressed via a URI constructed
as follows:
1) the base URI is the URI of the XML Schema namespace
2) the fragment identifier is the name of the datatype
For example, to address the int datatype, the URI is:
Additionally, each facet definition element can be uniquely
addressed via a URI constructed as follows:
1) the base URI is the URI of the XML Schema namespace
2) the fragment identifier is the name of the facet
For example, to address the maxInclusive facet, the URI is:
Additionally, each facet usage in a built-in datatype definition
can be uniquely addressed via a URI constructed as follows:
1) the base URI is the URI of the XML Schema namespace
2) the fragment identifier is the name of the datatype, followed
by a period (".") followed by the name of the facet
For example, to address the usage of the maxInclusive facet in
the definition of int, the URI is:
NOTATION cannot be used directly in a schema; rather a type
must be derived from it by specifying at least one enumeration
facet whose value is the name of a NOTATION declared in the
schema.
C.2 Illustrative XML representations for the built-in ordinary type definitions
The following, although in the form of a
schema document, contains XML representations of components already
present in all schemas by definition. It is included here as a form
of documentation.
Note:
These datatypes do not need to be declared in a schema document,
since they are automatically included in every schema.
Issue (B-1933):
It is an open question whether this and similar XML documents should
be accepted or rejected by software conforming to this specification.
The XML Schema Working Group expects to resolve this question in connection
with its work on issues relating to schema composition.
In the meantime, some existing schema processors will accept
declarations for them; other existing processors will reject such
declarations as duplicates.
Illustrative schema document for derived built-in type definitions
name NMTOKEN #REQUIRED>
name NMTOKEN #REQUIRED
value CDATA #REQUIRED>
]>
xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified"
xml:lang="en"
targetNamespace="http://www.w3.org/2001/XMLSchema">
This document contains XML representations for the
ordinary non-primitive built-in datatypes
pattern specifies the content of section 2.12 of XML 1.0e2
and RFC 3066 (Revised version of RFC 1766). N.B. RFC 3066 is now
obsolete; the grammar of RFC4646 is more restrictive. So strict
conformance to the rules for language codes requires extra checking
beyond validation against this type.
pattern matches production 7 from the XML spec
pattern matches production 5 from the XML spec
pattern matches production 4 from the Namespaces in XML spec
This type includes just those durations expressed in years and months.
Since the pattern given excludes days, hours, minutes, and seconds,
the values of this type have a seconds property of zero. They are
totally ordered.
This type includes just those durations expressed in days, hours, minutes, and seconds.
The pattern given excludes years and months, so the values of this type
have a months property of zero. They are totally ordered.
This datatype includes just those dateTime values Whose explicitTimezone
is present. They are totally ordered.
D Built-up Value Spaces
Some datatypes, such as
integer
, describe well-known mathematically abstract
systems. Others, such as the date/time datatypes, describe "real-life",
"applied" systems. Certain
of the systems described by datatypes, both abstract and
applied, have values in their value spaces most easily described as things
having several
properties
, which in turn have values which are
in some sense "primitive" or are from the value spaces of
simpler datatypes.
In
this document, the arguments to functions are assumed to be "call by
value" unless explicitly noted to the contrary, meaning that if the argument is modified
during the processing of the algorithm, that modification is
not
reflected in the
"outside world". On the other hand, the arguments to procedures are assumed
to be "call by location", meaning that modifications
are
so reflected,
since that is the only way the processing of the algorithm can have any effect.
Properties always have values.
[Definition:]
An
optional
property is
permitted
but not
required
to have
the distinguished
value
absent
[Definition:]
Throughout this
specification, the value
absent
is used
as a distinguished value to indicate that a given instance of a property
"has no value" or "is absent".
This should not be interpreted as constraining implementations, as for instance
between using a
null
value for such properties or not representing them at all.
Those
values that are more primitive, and are used (among other things) herein to
construct object value spaces but which we do not explicitly define are
described here:
number (without precision)
is an ordinary
mathematical number; 1, 1.0, and
1.000000000000 are the same
number. The decimal
numbers and integers
generally used in the algorithms of
appendix
Function
Definitions (§E)
are
such
ordinary numbers, not carrying precision.
[Definition:]
special value
is
an object
whose only relevant properties for purposes of this specification are that it
is distinct from, and unequal to, any other values (special or otherwise).
A few special values in different value spaces (e.g.
positiveInfinity
negativeInfinity
, and
notANumber
in
float
and
double
) share names. Thus, special values
can be distinguished from each other in the
general case by considering both the name and the primitive datatype of the value; in
some
cases, of course, the name alone suffices to identify the value uniquely.
Note:
In the case of
float
and
double
, the
special values
are members of the
datatype's
value space
D.1 Numerical Values
The following standard operators are defined here
in case the reader is unsure of their definition:
[Definition:]
If
and
are numbers, then
div
is the greatest integer
less than or equal to
[Definition:]
If
and
are numbers, then
mod
is
× (
div
) .
Note:
div
1 is
a convenient and short way of
expressing "the greatest integer
less
than or equal to
".
D.1.1 Exact Lexical Mappings
Numerals and Fragments Thereof
[45]
digit
::= [
0-9
[46]
unsignedNoDecimalPtNumeral
::=
digit
[47]
noDecimalPtNumeral
::= ('
' | '
')?
unsignedNoDecimalPtNumeral
[48]
fracFrag
::=
digit
[49]
unsignedDecimalPtNumeral
::= (
unsignedNoDecimalPtNumeral
fracFrag
?) | ('
fracFrag
[50]
unsignedFullDecimalPtNumeral
::=
unsignedNoDecimalPtNumeral
fracFrag
[51]
decimalPtNumeral
::= ('
' | '
')?
unsignedDecimalPtNumeral
[52]
unsignedScientificNotationNumeral
::= (
unsignedNoDecimalPtNumeral
unsignedDecimalPtNumeral
) ('
' | '
')
noDecimalPtNumeral
[53]
scientificNotationNumeral
::= ('
' | '
')?
unsignedScientificNotationNumeral
Generic Numeral-to-Number Lexical Mappings
unsignedNoDecimalMap
) → integer
Maps an
unsignedNoDecimalPtNumeral
to its numerical value.
noDecimalMap
) → integer
Maps an
noDecimalPtNumeral
to its numerical value.
unsignedDecimalPtMap
) → decimal number
Maps an
unsignedDecimalPtNumeral
to its numerical value.
decimalPtMap
) → decimal number
Maps a
decimalPtNumeral
to its numerical value.
scientificMap
) → decimal number
Maps a
scientificNotationNumeral
to its numerical value.
Generic Number to Numeral Canonical Mappings
unsignedNoDecimalPtCanonicalMap
) →
unsignedNoDecimalPtNumeral
Maps a nonnegative integer to a
unsignedNoDecimalPtNumeral
, its
canonical representation
noDecimalPtCanonicalMap
) →
noDecimalPtNumeral
Maps an integer to a
noDecimalPtNumeral
, its
canonical representation
unsignedDecimalPtCanonicalMap
) →
unsignedDecimalPtNumeral
Maps a nonnegative decimal number to a
unsignedDecimalPtNumeral
, its
canonical representation
decimalPtCanonicalMap
) →
decimalPtNumeral
Maps a decimal number to a
decimalPtNumeral
, its
canonical representation
unsignedScientificCanonicalMap
) →
unsignedScientificNotationNumeral
Maps a nonnegative decimal number to a
unsignedScientificNotationNumeral
, its
canonical representation
scientificCanonicalMap
) →
scientificNotationNumeral
Maps a decimal number to a
scientificNotationNumeral
, its
canonical representation
Some numerical datatypes include some or all of three
non-numerical
special values
positiveInfinity
negativeInfinity
, and
notANumber
. Their lexical spaces
include non-numeral lexical representations for these non-numeric values:
Special Non-numerical Lexical Representations Used With Numerical Datatypes
[54]
minimalNumericalSpecialRep
::= '
INF
' | '
-INF
' | '
NaN
[55]
numericalSpecialRep
::= '
+INF
' |
minimalNumericalSpecialRep
Lexical Mapping for Non-numerical
Special Values
Used With Numerical Datatypes
specialRepValue
) → a
special value
Maps the
lexical representations
of
special values
used with some
numerical datatypes to those
special values
Canonical Mapping for Non-numerical
Special Values
Used with Numerical Datatypes
specialRepCanonicalMap
) →
numericalSpecialRep
Maps the
special values
used with some numerical datatypes to their
canonical representations
D.2 Date/time Values
D.2.1
The Seven-property Model
D.2.2
Lexical Mappings
There are several different primitive but
related datatypes defined in the specification which pertain to
various combinations of dates and times, and parts thereof. They
all use related value-space models, which are described in detail in
this section. It is not difficult for a casual reader of the
descriptions of the individual datatypes elsewhere in this
specification to misunderstand some of the details of just what the
datatypes are intended to represent, so more detail is presented here
in this section.
All of the value spaces for dates and times
described here represent moments or periods of time in Universal
Coordinated Time (UTC).
[Definition:]
Universal
Coordinated Time
UTC
is an adaptation of TAI which closely approximates UT1 by adding
leap-seconds
to selected
UTC
days.
[Definition:]
leap-second
is an additional second added
to the last day of December, June, October, or March,
when such an adjustment is deemed necessary by the
International Earth Rotation and Reference Systems Service
in order to keep
UTC
within 0.9 seconds
of observed astronomical time. When leap seconds are
introduced, the last minute in the day has more than
sixty seconds.
In theory leap seconds can also be removed from a
day, but this has not yet occurred.
(See
[International Earth Rotation Service (IERS)]
[ITU-R TF.460-6]
.)
Leap seconds are
not
supported by the types defined
here.
Because
the
dateTime
type and
other date- and time-related types defined in this specification do
not support leap seconds, there are portions of the
UTC
timeline which cannot be represented by values of these
types. Users whose applications require that leap seconds be
represented and that date/time arithmetic take historically
occurring leap seconds into account will wish to make
appropriate adjustments at the application level, or to use
other types.
D.2.1 The Seven-property Model
There are two distinct ways to model moments in time: either
by tracking their year, month, day, hour, minute and second (with
fractional seconds as needed), or by tracking
their time (measured generally in seconds or
days) from some starting moment. Each has
its advantages. The two are isomorphic. For
definiteness, we choose to model the first
using five integer and one decimal number properties. We superimpose
the second by providing one decimal number-valued
function which gives the corresponding count of
seconds from zero (the "time on the time line").
There is also a seventh
integer
property which
specifies the time zone offset
as the number of minutes of offset from UTC. Values for the
six primary properties are always stored in
their
"local" values (the values shown in the lexical
representations), rather than converted to
UTC
Properties of
Date/time
Seven-property Models
year
an integer
month
an integer between 1 and 12 inclusive
day
an integer between 1 and
31 inclusive,
possibly
restricted further depending on
month
and
year
hour
an integer between 0 and 23 inclusive
minute
an integer between 0 and 59 inclusive
second
a decimal number greater than or equal
to
0 and less
than 60.
timezoneOffset
an
optional
integer between −840
and 840 inclusive
Non-negative values of the properties map
to the years, months, days of month, etc. of the Gregorian
calendar in the obvious way.
Values less than 1582 in the
year
property represent years in the
"proleptic Gregorian calendar".
A value of zero in the
year
property
represents the year 1 BCE;
a value of −1 represents the year 2 BCE, −2 is 3 BCE,
etc.
Note:
In version 1.0 of this specification, the
year
property was not permitted to have the value
zero. The year before the year 1 in the
proleptic Gregorian calendar, traditionally referred to as
1 BC or as
1 BCE, was represented by a
year
value of −1, 2 BCE by −2, and so
forth.
Of course, many, perhaps most,
references to 1 BCE (or 1 BC) actually refer not
to a year in the proleptic Gregorian calendar but to a year in the
Julian or "old style" calendar; the two correspond
approximately but not exactly to each other.
In this version of this specification,
two changes are made in order to agree with existing usage.
First,
year
is permitted to have the value zero.
Second, the interpretation of
year
values is changed accordingly:
year
value of zero represents 1 BCE, −1
represents 2 BCE, etc. This representation simplifies interval
arithmetic and leap-year calculation for dates before the common
era (which may be why astronomers
and others interested in such calculations with the proleptic
Gregorian calendar have adopted it), and is consistent with the
current edition of
[ISO 8601]
Note that 1 BCE, 5 BCE, and so on (years 0000, −0004, etc. in the
lexical representation defined here) are leap years in the proleptic
Gregorian calendar used for the date/time datatypes defined here.
Version 1.0 of this specification was unclear about the treatment of
leap years before the common era.
If existing
schemas or data specify dates of 29 February for any years before the
common era, then some values giving
a date of 29 February which were valid under a plausible
interpretation of XSD 1.0 will be invalid under this specification,
and some which were invalid will be valid. With that possible
exception, schemas and data valid
under the old interpretation remain valid under the new.
The model just described is called herein the
"seven-property" model for date/time
datatypes. It is used "as is"
for
dateTime
; all other date/time
datatypes except
duration
use the
same model except that some of the six primary
properties are
required
to have the
value
absent
, instead of being required
to have a numerical value. (An
optional
property, like
timezoneOffset
is always
permitted
to have the value
absent
.)
timezoneOffset
values are limited to 14 hours,
which is 840 (= 60 × 14) minutes.
Note:
Leap-seconds are not permitted
Readers
interested in when leap-seconds have been introduced should
consult
[USNO Historical List]
, which includes a list
of times when the difference between TAI and
UTC
has changed.
Because
the simple types defined here do not support leap seconds, they cannot be used
to represent the final second, in
UTC
of any of the days containing
one. If it is important, at the application level,
to track the occurrence of leap seconds, then users will need to make
special arrangements for special handling of them and
of time intervals crossing them.
While calculating, property values from the
dateTime
1972-12-31T00:00:00 are used to fill in
for those that are
absent
, except
that if
day
is
absent
but
month
is not, the largest permitted
day for that month is used.
Time on Timeline for Date/time Seven-property
Model Datatypes
timeOnTimeline
dt
) → decimal number
Maps a
date/timeSevenPropertyModel
value to the decimal number
representing its position on the "time line".
Values from any one date/time datatype using the seven-component
model (all except
duration
are ordered the same as their
timeOnTimeline
values,
except that if one value's
timezoneOffset
is
absent
and the other's is not, and using maximum and minimum
timezoneOffset
values for the one whose
timezoneOffset
is actually
absent
changes the resulting (strict)
inequality, the original two values are incomparable.
D.2.2 Lexical Mappings
[Definition:]
Each
lexical representation is made up
of certain
date/time fragments
, each of which
corresponds to a particular property of the datatype
value.
They are defined by
the following productions.
Date/time Lexical Representation Fragments
[56]
yearFrag
::= '
'?
(([
1-9
digit
digit
digit
+)) |
('
digit
digit
digit
))
[57]
monthFrag
::= ('
' [
1-9
]) |
('
' [
0-2
])
[58]
dayFrag
::= ('
' [
1-9
]) | ([
12
digit
) |
('
' [
01
])
[59]
hourFrag
::= ([
01
digit
) |
('
' [
0-3
])
[60]
minuteFrag
::= [
0-5
digit
[61]
secondFrag
::= ([
0-5
digit
) ('
digit
+)?
[62]
endOfDayFrag
::= '
24:00:00
' ('
' '
'+)?
[63]
timezoneFrag
::= '
| ('
' | '
') (('
digit
| '
' [
0-3
]) '
minuteFrag
| '
14:00
')
Each fragment other than
timezoneFrag
defines a subset of
the
lexical space
of
decimal
the corresponding
lexical mapping
is the
decimal
lexical mapping
restricted to that
subset. These fragment
lexical mappings
are combined
separately for each date/time datatype (other than
duration
) to make up
the complete lexical mapping
for
that datatype. The
yearFragValue
mapping is used to
obtain the value of the
year
property, the
monthFragValue
mapping is used to obtain the value of the
month
property, etc. Each datatype which specifies
some properties to be mandatorily
absent
also does not permit
the corresponding lexical fragments in its lexical representations.
Partial Date/time Lexical Mappings
yearFragValue
YR
) → integer
Maps a
yearFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
year
property of a
date/timeSevenPropertyModel
value.
monthFragValue
MO
) → integer
Maps a
monthFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
month
property of a
date/timeSevenPropertyModel
value.
dayFragValue
DA
) → integer
Maps a
dayFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
day
property of a
date/timeSevenPropertyModel
value.
hourFragValue
HR
) → integer
Maps a
hourFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
hour
property of a
date/timeSevenPropertyModel
value.
minuteFragValue
MI
) → integer
Maps a
minuteFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
minute
property of a
date/timeSevenPropertyModel
value.
secondFragValue
SE
) → decimal number
Maps a
secondFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto a decimal number, presumably the
second
property of a
date/timeSevenPropertyModel
value.
timezoneFragValue
TZ
) → integer
Maps a
timezoneFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
timezoneOffset
property of a
date/timeSevenPropertyModel
value.
Note:
The redundancy between
', '
+00:00
', and
-00:00
', and the possibility of trailing fractional
' digits for
secondFrag
, are the only
redundancies preventing these mappings from being one-to-one. There
is no
lexical mapping
for
endOfDayFrag
; it is handled
specially by the relevant
lexical mappings
. See, e.g.,
dateTimeLexicalMap
The following fragment
canonical
mappings
for each value-object
property are combined as appropriate to make the
canonical mapping
for each date/time datatype (other
than
duration
):
Partial Date/time Canonical Mappings
yearCanonicalFragmentMap
) →
yearFrag
Maps an integer, presumably the
year
property of a
date/timeSevenPropertyModel
value,
onto a
yearFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
monthCanonicalFragmentMap
) →
monthFrag
Maps an integer, presumably the
month
property of a
date/timeSevenPropertyModel
value,
onto a
monthFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
dayCanonicalFragmentMap
) →
dayFrag
Maps an integer, presumably the
day
property of a
date/timeSevenPropertyModel
value,
onto a
dayFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
hourCanonicalFragmentMap
) →
hourFrag
Maps an integer, presumably the
hour
property of a
date/timeSevenPropertyModel
value,
onto a
hourFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
minuteCanonicalFragmentMap
) →
minuteFrag
Maps an integer, presumably the
minute
property of a
date/timeSevenPropertyModel
value,
onto a
minuteFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
secondCanonicalFragmentMap
) →
secondFrag
Maps a decimal number, presumably the
second
property of a
date/timeSevenPropertyModel
value,
onto a
secondFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
timezoneCanonicalFragmentMap
) →
timezoneFrag
Maps an integer, presumably the
timezoneOffset
property of a
date/timeSevenPropertyModel
value,
onto a
timezoneFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
E Function
Definitions
The more important functions and
procedures defined here are summarized in the
text When there is a text summary, the name of the function in each is a
"hot-link" to the same name in the other. All other links
to these functions link to the complete definition in this section.
E.1 Generic Number-related Functions
The following functions are used with various numeric and date/time datatypes.
Auxiliary Functions for Operating on Numeral Fragments
digitValue
) → integer
Maps each digit to its numerical value.
Arguments:
matches
digit
Result:
a nonnegative integer less than ten
Algorithm:
Return
0 when
= '
' ,
1 when
= '
' ,
2 when
= '
' ,
etc.
digitSequenceValue
) → integer
Maps a sequence of digits to the position-weighted sum of the terms numerical values.
Arguments:
a finite sequence of
literals
, each term matching
digit
Result:
a nonnegative integer
Algorithm:
Return the sum of
digitValue
) × 10
length(
)−
where
runs over the domain of
fractionDigitSequenceValue
) → integer
Maps a sequence of digits to the position-weighted sum of the terms numerical values, weighted appropriately for fractional digits.
Arguments:
a finite sequence of
literals
, each term matching
digit
Result:
a nonnegative integer
Algorithm:
Return the sum of
digitValue
) − 10
where
runs over the domain of
fractionFragValue
) → decimal number
Maps a
fracFrag
to the appropriate fractional decimal number.
Arguments:
matches
fracFrag
Result:
a nonnegative decimal number
Algorithm:
is necessarily the left-to-right concatenation of a finite sequence
of
literals
, each term matching
digit
Return
fractionDigitSequenceValue
).
Generic Numeral-to-Number Lexical Mappings
unsignedNoDecimalMap
) → integer
Maps an
unsignedNoDecimalPtNumeral
to its numerical value.
Arguments:
matches
unsignedNoDecimalPtNumeral
Result:
a nonnegative integer
Algorithm:
is the left-to-right concatenation of a finite sequence
of
literals
, each term matching
digit
Return
digitSequenceValue
).
noDecimalMap
) → integer
Maps an
noDecimalPtNumeral
to its numerical value.
Arguments:
matches
noDecimalPtNumeral
Result:
an integer
Algorithm:
necessarily consists of an optional sign('
' or '
') and then
literal
that matches
unsignedNoDecimalPtNumeral
Return
−1 ×
unsignedNoDecimalMap
) when '
' is present, and
unsignedNoDecimalMap
) otherwise.
unsignedDecimalPtMap
) → decimal number
Maps an
unsignedDecimalPtNumeral
to its numerical value.
Arguments:
matches
unsignedDecimalPtNumeral
Result:
a nonnegative decimal number
Algorithm:
necessarily consists of an optional
literal
matching
unsignedNoDecimalPtNumeral
a decimal point, and then an optional
literal
matching
fracFrag
Return
unsignedNoDecimalMap
) when
is not present,
fractionFragValue
) when
is not present, and
unsignedNoDecimalMap
) +
fractionFragValue
otherwise.
decimalPtMap
) → decimal number
Maps a
decimalPtNumeral
to its numerical value.
Arguments:
matches
decimalPtNumeral
Result:
a decimal number
Algorithm:
necessarily consists of an optional sign('
' or '
') and then
an instance
of
unsignedDecimalPtNumeral
Return
unsignedDecimalPtMap
) when '
' is present, and
unsignedDecimalPtMap
) otherwise.
scientificMap
) → decimal number
Maps a
scientificNotationNumeral
to its numerical value.
Arguments:
matches
scientificNotationNumeral
Result:
a decimal number
Algorithm:
necessarily consists of an instance
of either
noDecimalPtNumeral
or
decimalPtNumeral
, either an '
' or an '
', and then an instance
of
noDecimalPtNumeral
Return
decimalPtMap
) × 10 ^
unsignedDecimalPtMap
when a '
' is present in
, and
noDecimalMap
) × 10 ^
unsignedDecimalPtMap
otherwise.
Auxiliary Functions for Producing Numeral Fragments
digit
) →
digit
Maps each integer between 0 and 9 to the corresponding
digit
Arguments:
between 0 and 9 inclusive
Result:
matches
digit
Algorithm:
Return
' when
= 0 ,
' when
= 1 ,
' when
= 2 ,
etc.
digitRemainderSeq
) → sequence of integers
Maps each nonnegative integer to a sequence of integers used by
digitSeq
to ultimately create an
unsignedNoDecimalPtNumeral
Arguments:
a nonnegative integer
Result:
sequence of nonnegative integers
Algorithm:
Return that sequence
for which
and
+1
div
10 .
digitSeq
) → sequence of integers
Maps each nonnegative integer to a sequence of integers used by
unsignedNoDecimalPtCanonicalMap
to create an
unsignedNoDecimalPtNumeral
Arguments:
a nonnegative integer
Result:
sequence of integers where each term is between 0 and 9 inclusive
Algorithm:
Return that sequence
for which
digitRemainderSeq
mod
10 .
lastSignificantDigit
) → integer
Maps a sequence of nonnegative integers to the index of the first zero term.
Arguments:
a sequence of nonnegative integers
Result:
a nonnegative integer
Algorithm:
Return the smallest nonnegative integer
such that
+1
is 0.
FractionDigitRemainderSeq
) → sequence of decimal numbers
Maps each nonnegative decimal number less than 1 to a sequence of decimal numbers used by
fractionDigitSeq
to ultimately create an
unsignedNoDecimalPtNumeral
Arguments:
nonnegative and less than 1
Result:
a sequence of nonnegative decimal numbers
Algorithm:
Return that sequence
for which
− 10 , and
+1
= (
mod
1) − 10 .
fractionDigitSeq
) → sequence of integers
Maps each nonnegative decimal number less than 1 to a sequence of integers used by
fractionDigitsCanonicalFragmentMap
to ultimately create an
unsignedNoDecimalPtNumeral
Arguments:
nonnegative and less than 1
Result:
a sequence of integer;s where each term is between 0 and 9 inclusive
Algorithm:
Return that sequence
for which
FractionDigitRemainderSeq
div
1 .
fractionDigitsCanonicalFragmentMap
) →
fracFrag
Maps each nonnegative decimal number less than 1 to a
literal
used by
unsignedDecimalPtCanonicalMap
to create an
unsignedDecimalPtNumeral
Arguments:
nonnegative and less than 1
Result:
matches
fracFrag
Algorithm:
Return
digit
fractionDigitSeq
) & . . . &
digit
fractionDigitSeq
lastSignificantDigit
FractionDigitRemainderSeq
))
) .
Generic Number to Numeral Canonical Mappings
unsignedNoDecimalPtCanonicalMap
) →
unsignedNoDecimalPtNumeral
Maps a nonnegative integer to a
unsignedNoDecimalPtNumeral
, its
canonical representation
Arguments:
a nonnegative integer
Result:
matches
unsignedNoDecimalPtNumeral
Algorithm:
Return
digit
digitSeq
lastSignificantDigit
digitRemainderSeq
))
) &
. . . &
digit
digitSeq
) . (Note
that the concatenation is in reverse order.)
noDecimalPtCanonicalMap
) →
noDecimalPtNumeral
Maps an integer to a
noDecimalPtNumeral
, its
canonical representation
Arguments:
an integer
Result:
matches
noDecimalPtNumeral
Algorithm:
Return
' &
unsignedNoDecimalPtCanonicalMap
(−
when
is negative,
unsignedNoDecimalPtCanonicalMap
) otherwise.
unsignedDecimalPtCanonicalMap
) →
unsignedDecimalPtNumeral
Maps a nonnegative decimal number to a
unsignedDecimalPtNumeral
, its
canonical representation
Arguments:
a nonnegative decimal number
Result:
matches
unsignedDecimalPtNumeral
Algorithm:
Return
unsignedNoDecimalPtCanonicalMap
div
1) &
' &
fractionDigitsCanonicalFragmentMap
mod
1) .
decimalPtCanonicalMap
) →
decimalPtNumeral
Maps a decimal number to a
decimalPtNumeral
, its
canonical representation
Arguments:
a decimal number
Result:
matches
decimalPtNumeral
Algorithm:
Return
' &
unsignedDecimalPtCanonicalMap
(−
when
is negative,
unsignedDecimalPtCanonicalMap
) otherwise.
unsignedScientificCanonicalMap
) →
unsignedScientificNotationNumeral
Maps a nonnegative decimal number to a
unsignedScientificNotationNumeral
, its
canonical representation
Arguments:
a nonnegative decimal number
Result:
matches
unsignedScientificNotationNumeral
Algorithm:
Return
unsignedDecimalPtCanonicalMap
/ 10
log(
div
) &
' &
noDecimalPtCanonicalMap
(log(
div
1)
scientificCanonicalMap
) →
scientificNotationNumeral
Maps a decimal number to a
scientificNotationNumeral
, its
canonical representation
Arguments:
a decimal number
Result:
matches
scientificNotationNumeral
Algorithm:
Return
' &
unsignedScientificCanonicalMap
(−
when
is negative,
unsignedScientificCanonicalMap
) otherwise.
For example:
123.4567
mod
1 = 0.4567 and 123.4567
div
1 = 123 .
digitRemainderSeq
(123) is 123 , 12 , 1 , 0 , 0 , . . . .
digitSeq
(123) is 3 , 2 , 1 , 0 , 0 , . . . .
lastSignificantDigit
digitRemainderSeq
(123)) = 2 (Sequences count from 0.)
unsignedNoDecimalPtCanonicalMap
(123) = '
123
FractionDigitRemainderSeq
(0.4567) is 4.567 , 5.67 , 6.7 , 7 , 0 , 0 , . . . .
fractionDigitSeq
(0.4567) is 4 , 5 , 6 , 7 , 0 , 0 , . . . .
lastSignificantDigit
FractionDigitRemainderSeq
(0.4567)) = 3
fractionDigitsCanonicalFragmentMap
(0.4567) = '
4567
unsignedDecimalPtCanonicalMap
(123.4567) = '
123.4567
Lexical Mapping for Non-numerical
Special Values
Used With Numerical Datatypes
specialRepValue
) → a
special value
Maps the
lexical representations
of
special values
used with some
numerical datatypes to those
special values
Arguments:
matches
numericalSpecialRep
Result:
one of
positiveInfinity
negativeInfinity
, or
notANumber
Algorithm:
Return
positiveInfinity
when
is
INF
' or '
+INF
',
negativeInfinity
when
is
-INF
', and
notANumber
when
is
NaN
Canonical Mapping for Non-numerical
Special Values
Used with Numerical Datatypes
specialRepCanonicalMap
) →
numericalSpecialRep
Maps the
special values
used with some numerical datatypes to their
canonical representations
Arguments:
one of
positiveInfinity
negativeInfinity
, and
notANumber
Result:
matches
numericalSpecialRep
Algorithm:
Return
INF
' when
is
positiveInfinity
-INF
' when
is
negativeInfinity
NaN
' when
is
notANumber
Lexical Mapping
decimalLexicalMap
LEX
) →
decimal
Maps a
decimalLexicalRep
onto a
decimal
value.
Arguments:
LEX
matches
decimalLexicalRep
Result:
decimal
value
Algorithm:
Let
be a
decimal
value.
Set
to
noDecimalMap
LEX
) when
LEX
is an instance of
noDecimalPtNumeral
, and
decimalPtMap
LEX
) when
LEX
is an instance of
decimalPtNumeral
Return
Canonical Mapping
decimalCanonicalMap
) →
decimalLexicalRep
Maps a
decimal
to its
canonical representation
decimalLexicalRep
Arguments:
decimal
value
Result:
literal
matching
decimalLexicalRep
Algorithm:
If
is an integer, then return
noDecimalPtCanonicalMap
).
Otherwise, return
decimalPtCanonicalMap
).
Auxiliary Functions
for Binary Floating-point Lexical/Canonical Mappings
floatingPointRound
nV
cWidth
eMin
eMax
) → decimal number or
special value
Rounds a non-zero decimal number to the nearest floating-point value.
Arguments:
nV
an initially non-zero decimal number
(may be
set to zero during calculations)
cWidth
a positive integer
eMin
an integer
eMax
an integer greater than
eMin
Result:
a decimal number or
special value
INF
or −
INF
Algorithm:
Let
be an integer
initially 1,
be a nonnegative integer, and
be an integer.
Set
to −1 when
nV
< 0 .
So select
that
cWidth
× 2
−1)
≤ |
nV
cWidth
× 2
So select
that
− 1) × 2
≤ |
nV
| <
× 2
when
eMax
(overflow)
return:
positiveInfinity
when
is positive, and
negativeInfinity
otherwise.
otherwise:
When
eMin
(underflow):
Set
eMin
So select
that
− 1) × 2
≤ |
nV
| <
× 2
Set
nV
to
× 2
when
nV
| >
× 2
− 2
−1)
− 1) × 2
when
nV
| <
× 2
− 2
−1)
× 2
or
− 1) × 2
according to whether
is even
or
− 1 is even, otherwise (i.e.,
nV
| =
× 2
− 2
−1)
the midpoint between the two values).
Return
nV
when
nV
< 2
cWidth
× 2
eMax
positiveInfinity
when
is positive, and
negativeInfinity
otherwise.
Note:
Implementers will find the algorithms of
[Clinger, WD (1990)]
more efficient in memory than the simple abstract algorithm employed above.
round
) → decimal number
Maps a decimal number to that value rounded by some power of 10.
Arguments:
a decimal number
a nonnegative integer
Result:
a decimal number
Algorithm:
Return
((
/ 10
+ 0.5)
div
1) × 10
floatApprox
) → decimal number
Maps a decimal number
× 10
) to
successive approximations.
Arguments:
a nonnegative integer
an integer
a nonnegative integer
Result:
a decimal number
Algorithm:
Return
round
) × 10
Lexical Mapping
floatLexicalMap
LEX
) →
float
Maps a
floatRep
onto a
float
value.
Arguments:
LEX
matches
floatRep
Result:
float
value
Algorithm:
Let
nV
be a decimal number or
special value
(INF or −INF).
Return
specialRepValue
LEX
) when
LEX
is an instance of
numericalSpecialRep
otherwise (
LEX
is a numeral):
Set
nV
to
noDecimalMap
LEX
) when
LEX
is an instance of
noDecimalPtNumeral
decimalPtMap
LEX
) when
LEX
is an instance of
decimalPtNumeral
, and
scientificMap
LEX
) otherwise
LEX
is an instance of
scientificNotationNumeral
).
Set
nV
to
floatingPointRound
nV
, 24, −149, 104)
when
nV
is not zero.
floatingPointRound
may nonetheless return zero, or INF or −INF.)
Return:
When
nV
is zero:
negativeZero
when
the first character of
LEX
is '
', and
positiveZero
otherwise.
nV
otherwise.
Note:
This specification permits the substitution of any other rounding algorithm
which conforms to the requirements of
[IEEE 754-2008]
Lexical Mapping
doubleLexicalMap
LEX
) →
double
Maps a
doubleRep
onto a
double
value.
Arguments:
LEX
matches
doubleRep
Result:
double
value
Algorithm:
Let
nV
be a decimal number or
special value
(INF or −INF).
Return
specialRepValue
LEX
) when
LEX
is an instance of
numericalSpecialRep
otherwise (
LEX
is a numeral):
Set
nV
to
noDecimalMap
LEX
) when
LEX
is an instance of
noDecimalPtNumeral
decimalPtMap
LEX
) when
LEX
is an instance of
decimalPtNumeral
, and
scientificMap
LEX
) otherwise
LEX
is an instance of
scientificNotationNumeral
).
Set
nV
to
floatingPointRound
nV
, 53, −1074, 971)
when
nV
is not zero.
floatingPointRound
may nonetheless return zero, or INF or −INF.)
Return:
When
nV
is zero:
negativeZero
when
the first character of
LEX
is '
', and
positiveZero
otherwise.
nV
otherwise.
Note:
This specification permits the substitution of any other rounding algorithm
which conforms to the requirements of
[IEEE 754-2008]
Canonical Mapping
floatCanonicalMap
) →
floatRep
Maps a
float
to its
canonical representation
, a
floatRep
Arguments:
float
value
Result:
literal
matching
floatRep
Algorithm:
Let
be a nonnegative integer
be an integer intially 1,
be a positive integer, and
be an integer.
Return
specialRepCanonicalMap
when
is one of
positiveInfinity
negativeInfinity
, or
notANumber
return '
0.0E0
' when
is
positiveZero
return '
-0.0E0
' when
is
negativeZero
otherwise (
is numeric and non-zero):
Set
to −1 when
< 0 .
Let
be the smallest integer for which there exists
an integer
for which
| =
× 10
Let
be log
10
(|
| /
(so that
| =
× 10
).
Let
be the largest nonnegative integer for which
× 10
floatingPointRound
floatApprox
), 24, −149, 104)
Return
scientificCanonicalMap
floatApprox
)) .
Canonical Mapping
doubleCanonicalMap
) →
doubleRep
Maps a
double
to its
canonical representation
, a
doubleRep
Arguments:
double
value
Result:
literal
matching
doubleRep
Algorithm:
Let
be a nonnegative integer
be an integer intially 1,
be a positive integer, and
be an integer.
Return
specialRepCanonicalMap
when
is one of
positiveInfinity
negativeInfinity
, or
notANumber
return '
0.0E0
' when
is
positiveZero
return '
-0.0E0
' when
is
negativeZero
otherwise (
is numeric and non-zero):
Set
to −1 when
< 0 .
Let
be the smallest integer for which there exists
an integer
for which
| =
× 10
Let
be log
10
(|
| /
(so that
| =
× 10
).
Let
be the largest nonnegative integer for which
× 10
floatingPointRound
floatApprox
), 53, −1074, 971)
Return
scientificCanonicalMap
floatApprox
)) .
E.2 Duration-related Definitions
The following functions are primarily
used with the
duration
datatype and its
derivatives.
Auxiliary
duration
-related
Functions Operating on Representation Fragments
duYearFragmentMap
) → integer
Maps a
duYearFrag
to an integer, intended as part of the value of the
months
property of a
duration
value.
Arguments:
matches
duYearFrag
Result:
a nonnegative integer
Algorithm:
is necessarily the letter '
' followed by a numeral
Return
noDecimalMap
).
duMonthFragmentMap
) → integer
Maps a
duMonthFrag
to an integer, intended as part of the value of the
months
property of a
duration
value.
Arguments:
matches
duYearFrag
Result:
a nonnegative integer
Algorithm:
is necessarily the letter '
' followed by a numeral
Return
noDecimalMap
).
duDayFragmentMap
) → integer
Maps a
duDayFrag
to an integer, intended as part of the value of the
seconds
property of a
duration
value.
Arguments:
matches
duDayFrag
Result:
a nonnegative integer
Algorithm:
is necessarily the letter '
' followed by a numeral
Return
noDecimalMap
).
duHourFragmentMap
) → integer
Maps a
duHourFrag
to an integer, intended as part of the value of the
seconds
property of a
duration
value.
Arguments:
matches
duHourFrag
Result:
a nonnegative integer
Algorithm:
is necessarily the letter '
' followed by a numeral
Return
noDecimalMap
).
duMinuteFragmentMap
) → integer
Maps a
duMinuteFrag
to an integer, intended as part of the value of the
seconds
property of a
duration
value.
Arguments:
matches
duMinuteFrag
Result:
a nonnegative integer
Algorithm:
is necessarily the letter '
' followed by a numeral
Return
noDecimalMap
).
duSecondFragmentMap
) → decimal number
Maps a
duSecondFrag
to a decimal number, intended as part of the value of the
seconds
property of a
duration
value.
Arguments:
matches
duSecondFrag
Result:
a nonnegative decimal number
Algorithm:
is necessarily '
' followed by a numeral
Return
decimalPtMap
) when '
' occurs
in
, and
noDecimalMap
) otherwise.
duYearMonthFragmentMap
YM
) → integer
Maps a
duYearMonthFrag
into an integer, intended as part of the
months
property of a
duration
value.
Arguments:
YM
matches
duYearMonthFrag
Result:
a nonnegative integer
Algorithm:
YM
necessarily consists of an
instance
of
duYearFrag
and/or an instance
of
duMonthFrag
Let
be
duYearFragmentMap
) (or 0 if
is not present) and
be
duMonthFragmentMap
) (or 0 if
is not present).
Return 12 ×
duTimeFragmentMap
) → decimal number
Maps a
duTimeFrag
into a decimal number, intended as part of the
seconds
property of a
duration
value.
Arguments:
matches
duTimeFrag
Result:
a nonnegative decimal number
Algorithm:
necessarily consists of an instance
of
duHourFrag
, and/or an instance
of
duMinuteFrag
, and/or an instance
of
duSecondFrag
Let
be
duDayFragmentMap
(or 0 if
is not present),
be
duMinuteFragmentMap
(or 0 if
is not present), and
be
duSecondFragmentMap
(or 0 if
is not present).
Return
3600 ×
+ 60 ×
+ s .
duDayTimeFragmentMap
DT
) → decimal number
Maps a
duDayTimeFrag
into a decimal number, which is the potential value of the
seconds
property of a
duration
value.
Arguments:
DT
matches
duDayTimeFrag
Result:
a nonnegative decimal number
Algorithm:
DT
necessarily consists of an instance
of
duDayFrag
and/or an instance
of
duTimeFrag
Let
be
duDayFragmentMap
(or 0 if
is not present) and
be
duTimeFragmentMap
(or 0 if
is not present).
Return 86400 ×
The
duration
Lexical Mapping
durationMap
DUR
) →
duration
Separates the
durationLexicalRep
into the month part and the seconds part,
then maps them into the
months
and
seconds
of the
duration
value.
Arguments:
DUR
matches
durationLexicalRep
Result:
a complete
duration
value
Algorithm:
DUR
consists of possibly a
leading '
', followed by
' and then an instance
of
duYearMonthFrag
and/or an instance
of
duDayTimeFrag
Return a
duration
whose
months
value is
0 if
is not present,
duYearMonthFragmentMap
) if
both '
' and
are present, and
duYearMonthFragmentMap
) otherwise.
and whose
seconds
value is
0 if
is not present,
duDayTimeFragmentMap
) if
both '
' and
are present, and
duDayTimeFragmentMap
) otherwise.
The
yearMonthDuration
Lexical Mapping
yearMonthDurationMap
YM
) →
yearMonthDuration
Maps the lexical representation into the
months
of a
yearMonthDuration
value. (A
yearMonthDuration
's
seconds
is always
zero.)
yearMonthDurationMap
is a restriction of
durationMap
Arguments:
YM
matches
yearMonthDurationLexicalRep
Result:
a complete
yearMonthDuration
value
Algorithm:
YM
necessarily consists of
an optional leading '
', followed by
' and then an instance
of
duYearMonthFrag
Return a
yearMonthDuration
whose
months
value is
duYearMonthFragmentMap
) if '
' is
present in
YM
and
duYearMonthFragmentMap
) otherwise, and
seconds
value is (necessarily) 0.
The
dayTimeDuration
Lexical Mapping
dayTimeDurationMap
DT
) →
dayTimeDuration
Maps the lexical representation into the
seconds
of a
dayTimeDuration
value. (A
dayTimeDuration
's
months
is always
zero.)
dayTimeDurationMap
is a restriction of
durationMap
Arguments:
DT
dayTimeDuration
value
Result:
a complete
dayTimeDuration
value
Algorithm:
DT
necessarily
consists of possibly a leading '
', followed by
' and then an instance
of
duDayTimeFrag
Return a
dayTimeDuration
whose
months
value is (necessarily) 0, and
seconds
value is
duDayTimeFragmentMap
) if '
' is
present in
DT
and
duDayTimeFragmentMap
) otherwise.
Auxiliary
duration
-related Functions
Producing Representation Fragments
duYearMonthCanonicalFragmentMap
ym
) →
duYearMonthFrag
Maps a nonnegative integer, presumably the absolute value of the
months
of a
duration
value, to a
duYearMonthFrag
, a fragment of a
duration
lexical representation
Arguments:
ym
a nonnegative integer
Result:
literal
matching
duYearMonthFrag
Algorithm:
Let
be
ym
div
12 , and
be
ym
mod
12 ,
Return
unsignedNoDecimalPtCanonicalMap
) & '
' &
unsignedNoDecimalPtCanonicalMap
) & '
when neither
nor
is zero,
unsignedNoDecimalPtCanonicalMap
) & '
when
is not zero but
is, and
unsignedNoDecimalPtCanonicalMap
) & '
when
is zero.
duDayCanonicalFragmentMap
) →
duDayFrag
Maps a nonnegative integer, presumably the day normalized value from the
seconds
of a
duration
value, to a
duDayFrag
, a fragment of a
duration
lexical representation
Arguments:
a nonnegative integer
Result:
literal
matching
duDayFrag
Algorithm:
Return
unsignedNoDecimalPtCanonicalMap
) & '
when
is not zero, and
the empty string ('') when
is zero.
duHourCanonicalFragmentMap
) →
duHourFrag
Maps a nonnegative integer, presumably the hour normalized value from the
seconds
of a
duration
value, to a
duHourFrag
, a fragment of a
duration
lexical representation
Arguments:
a nonnegative integer
Result:
literal
matching
duHourFrag
Algorithm:
Return
unsignedNoDecimalPtCanonicalMap
) & '
when
is not zero, and
the empty string ('') when
is zero.
duMinuteCanonicalFragmentMap
) →
duMinuteFrag
Maps a nonnegative integer, presumably the minute normalized value from the
seconds
of a
duration
value, to a
duMinuteFrag
, a fragment of a
duration
lexical representation
Arguments:
a nonnegative integer
Result:
literal
matching
duMinuteFrag
Algorithm:
Return
unsignedNoDecimalPtCanonicalMap
) & '
when
is not zero, and
the empty string ('') when
is zero.
duSecondCanonicalFragmentMap
) →
duSecondFrag
Maps a nonnegative decimal number, presumably the second normalized value from the
seconds
of a
duration
value, to a
duSecondFrag
, a fragment of a
duration
lexical representation
Arguments:
a nonnegative decimal number
Result:
matches
duSecondFrag
Algorithm:
Return
unsignedNoDecimalPtCanonicalMap
) & '
when
is a non-zero integer,
unsignedDecimalPtCanonicalMap
) & '
when
is not an integer, and
the empty string ('') when
is zero.
duTimeCanonicalFragmentMap
) →
duTimeFrag
Maps three nonnegative numbers, presumably the hour, minute, and second normalized values from a
duration
's
seconds
, to a
duTimeFrag
, a fragment of a
duration
lexical representation
Arguments:
a nonnegative integer
a nonnegative integer
a nonnegative decimal number
Result:
literal
matching
duTimeFrag
Algorithm:
Return
' &
duHourCanonicalFragmentMap
) &
duMinuteCanonicalFragmentMap
) &
duSecondCanonicalFragmentMap
when
, and
are not all zero, and
the empty string ('') when all arguments are zero.
duDayTimeCanonicalFragmentMap
ss
) →
duDayTimeFrag
Maps a nonnegative decimal number, presumably the absolute value of the
seconds
of a
duration
value, to a
duDayTimeFrag
, a fragment of a
duration
lexical representation
Arguments:
ss
a nonnegative decimal number
Result:
matches
duDayTimeFrag
Algorithm:
Let
is
ss
div
86400 ,
is
ss
mod
86400)
div
3600 ,
is
ss
mod
3600)
div
60 , and
is
ss
mod
60 ,
Return
duDayCanonicalFragmentMap
) &
duTimeCanonicalFragmentMap
when
ss
is not zero and
T0S
' when
ss
is zero.
The
duration
Canonical Mapping
durationCanonicalMap
) →
durationLexicalRep
Maps a
duration
's property values to
durationLexicalRep
fragments and combines the fragments into a complete
durationLexicalRep
Arguments:
a complete
duration
value
Result:
matches
durationLexicalRep
Algorithm:
Let
be
's
months
be
's
seconds
, and
sgn
be '
' if
or
is negative and
the empty string ('') otherwise.
Return
sgn
& '
' &
duYearMonthCanonicalFragmentMap
(|
|) &
duDayTimeCanonicalFragmentMap
(|
|)
when neither
nor
is zero,
sgn
& '
' &
duYearMonthCanonicalFragmentMap
(|
|)
when
is not zero but
is, and
sgn
& '
' &
duDayTimeCanonicalFragmentMap
(|
|)
when
is zero.
The
yearMonthDuration
Canonical Mapping
yearMonthDurationCanonicalMap
ym
) →
yearMonthDurationLexicalRep
Maps a
yearMonthDuration
's
months
value to
yearMonthDurationLexicalRep
. (The
seconds
value is necessarily zero and is ignored.)
yearMonthDurationCanonicalMap
is a restriction of
durationCanonicalMap
Arguments:
ym
a complete
yearMonthDuration
value
Result:
matches
yearMonthDurationLexicalRep
Algorithm:
Let
be
ym
's
months
and
sgn
be '
' if
is negative and
the empty string ('') otherwise.
Return
sgn
& '
' &
duYearMonthCanonicalFragmentMap
(|
|) .
The
dayTimeDuration
Canonical Mapping
dayTimeDurationCanonicalMap
dt
) →
dayTimeDurationLexicalRep
Maps a
dayTimeDuration
's
seconds
value to
dayTimeDurationLexicalRep
. (The
months
value is necessarily zero and is ignored.)
dayTimeDurationCanonicalMap
is a restriction of
durationCanonicalMap
Arguments:
dt
a complete
dayTimeDuration
value
Result:
matches
dayTimeDurationLexicalRep
Algorithm:
Let
be
dt
's
months
and
sgn
be '
' if
is negative and
the empty string ('') otherwise.
Return
sgn
& '
' &
duYearMonthCanonicalFragmentMap
(|
|) .
E.3 Date/time-related Definitions
E.3.1
Normalization of property values
E.3.2
Auxiliary Functions
E.3.3
Adding durations to dateTimes
E.3.4
Time on timeline
E.3.5
Lexical mappings
E.3.6
Canonical Mappings
E.3.1 Normalization of property values
When adding and subtracting numbers from date/time properties, the
immediate results may not conform to the limits specified.
Accordingly, the following procedures are used to
"normalize" potential property values to
corresponding values that do conform to the appropriate limits.
Normalization is required when dealing with time zone offset changes (as when
converting to
UTC
from
"local"
values) and when
adding
duration
values to or subtracting them from
dateTime
values.
Date/time Datatype Normalizing Procedures
normalizeMonth
yr
mo
If month (
mo
) is out of range,
adjust month and year (
yr
) accordingly;
otherwise, make no change.
Arguments:
yr
an integer
mo
an integer
Algorithm:
Add (
mo
− 1)
div
12 to
yr
Set
mo
to
mo
− 1)
mod
12 + 1 .
normalizeDay
yr
mo
da
If
month (
mo
) is out of range, or day (
da
) is
out of range for the appropriate month, then adjust values accordingly,
otherwise make no change.
Arguments:
yr
an integer
mo
an integer
da
an integer
Algorithm:
normalizeMonth
yr
mo
Repeat until
da
is positive and not greater than
daysInMonth
yr
mo
):
If
da
exceeds
daysInMonth
yr
mo
then:
Subtract that limit from
da
Add 1 to
mo
normalizeMonth
yr
mo
If
da
is not positive then:
Subtract 1 from
mo
normalizeMonth
yr
mo
Add the new upper limit from the table to
da
normalizeMinute
yr
mo
da
hr
mi
Normalizes minute, hour, month, and year values to values that obey the appropriate constraints.
Arguments:
yr
an integer
mo
an integer
da
an integer
hr
an integer
mi
an integer
Algorithm:
Add
mi
div
60 to
hr
Set
mi
to
mi
mod
60 .
Add
hr
div
24 to
da
Set
hr
to
hr
mod
24 .
normalizeDay
yr
mo
da
).
normalizeSecond
yr
mo
da
hr
mi
se
Normalizes second, minute, hour, month, and year values to values that obey the appropriate
constraints. (This algorithm ignores leap seconds.)
Arguments:
yr
an integer
mo
an integer
da
an integer
hr
an integer
mi
an integer
se
a decimal number
Algorithm:
Add
se
div
60 to
mi
Set
se
to
se
mod
60 .
normalizeMinute
yr
mo
da
hr
mi
).
E.3.2 Auxiliary Functions
Date/time Auxiliary Functions
daysInMonth
) → integer
Returns the number of the last day of the month
for any combination of year and month.
Arguments:
an
optional
integer
an integer between 1 and 12
Result:
between 28 and 31 inclusive
Algorithm:
Return:
28 when
is 2 and
is not evenly divisible by 4,
or is evenly divisible by 100 but not by 400,
or is
absent
29 when
is 2 and
is evenly divisible by 400,
or is evenly divisible by 4 but not by 100,
30 when
is 4, 6, 9, or 11,
31 otherwise (
is 1, 3, 5, 7, 8, 10, or 12)
newDateTime
Yr
Mo
Da
Hr
Mi
Se
Tz
) → an instance of the
date/timeSevenPropertyModel
Returns an instance of the
date/timeSevenPropertyModel
with
property values as specified in the arguments. If an argument is
omitted, the corresponding property is set to
absent
Arguments:
Yr
an
optional
integer
Mo
an
optional
integer between 1 and 12 inclusive
Da
an
optional
integer between 1 and 31 inclusive
Hr
an
optional
integer between 0 and 24 inclusive
Mi
an
optional
integer between 0 and 59 inclusive
Se
an
optional
decimal number greater than or equal to 0 and less than
60
Tz
an
optional
integer
between −840 and 840 inclusive.
Result:
Algorithm:
Let
dt
be an instance of the
date/timeSevenPropertyModel
yr
be
Yr
when
Yr
is not
absent
, otherwise 1
mo
be
Mo
when
Mo
is
not
absent
, otherwise 1
da
be
Da
when
Da
is
not
absent
, otherwise 1
hr
be
Hr
when
Hr
is
not
absent
, otherwise 0
mi
be
Mi
when
Mi
is
not
absent
, otherwise 0
se
be
Se
when
Se
is
not
absent
, otherwise 0
normalizeSecond
yr
mo
da
hr
mi
se
Set the
year
property of
dt
to
absent
when
Yr
is
absent
, otherwise
yr
Set the
month
property of
dt
to
absent
when
Mo
is
absent
, otherwise
mo
Set the
day
property of
dt
to
absent
when
Da
is
absent
, otherwise
da
Set the
hour
property of
dt
to
absent
when
Hr
is
absent
, otherwise
hr
Set the
minute
property of
dt
to
absent
when
Mi
is
absent
, otherwise
mi
Set the
second
property of
dt
to
absent
when
Se
is
absent
, otherwise
se
Set the
timezoneOffset
property of
dt
to
Tz
Return
dt
E.3.3 Adding durations to dateTimes
Given a
dateTime
and a
duration
, function
dateTimePlusDuration
specifies how to compute a
dateTime
, where
is the end of the time period with start
and
duration
i.e.
. Such computations are used, for example, to
determine whether a
dateTime
is within a specific time
period. This
algorithm
can also be applied,
when applications need the operation,
to the addition of
duration
s to the datatypes
date
gYearMonth
gYear
gDay
and
gMonth
each of which can be viewed as
denoting a set of
dateTime
s. In such cases, the addition is made to the
first or starting
dateTime
in the set.
Note that the extension of this
algorithm to types other than
dateTime
is not
needed for schema-validity assessment.
Essentially, this calculation adds the
months
and
seconds
properties of the
duration
value separately to the
dateTime
value. The
months
value
is added to the starting
dateTime
value first. If the
day is out of range for the new
month value, it is
pinned
to be within range. Thus April 31 turns into April 30. Then the
seconds
value
is added. This latter addition can
cause the year,
month, day, hour, and minute to change.
Leap seconds are
ignored
by the computation. All calculations
use 60 seconds per minute.
Thus the addition of either PT1M or PT60S to any dateTime will always
produce the same result. This is a special definition of addition which
is designed to match common practice, and—most importantly—be stable
over time.
A definition that attempted to take leap-seconds into account would
need to be constantly updated, and could not predict the results of
future implementation's additions. The decision to introduce a leap
second in
UTC
is the responsibility of the
[International Earth Rotation Service (IERS)]
. They make periodic
announcements as to when leap seconds are to be added, but this is not
known more than a year in advance. For more information on leap
seconds, see
[U.S. Naval Observatory Time Service Department]
Adding
duration
to
dateTime
dateTimePlusDuration
du
dt
) →
dateTime
Adds a
duration
to a
dateTime
value, producing another
dateTime
value.
Arguments:
du
duration
value
dt
dateTime
value
Result:
dateTime
value
Algorithm:
Let
yr
be
dt
's
year
mo
be
dt
's
month
da
be
dt
's
day
hr
be
dt
's
hour
mi
be
dt
's
minute
, and
se
be
dt
's
second
tz
be
dt
's
timezoneOffset
Add
du
's
months
to
mo
normalizeMonth
yr
mo
). (I.e., carry any
over- or underflow, adjust month.)
Set
da
to min(
da
daysInMonth
yr
mo
)).
(I.e.,
pin
the value if necessary.)
Add
du
's
seconds
to
se
normalizeSecond
yr
mo
da
hr
mi
se
).
(I.e., carry over- or underflow of seconds up to minutes, hours, etc.)
Return
newDateTime
yr
mo
da
hr
mi
se
tz
This algorithm may be applied to date/time types
other than
dateTime
, by
For each
absent
property, supply the minimum legal value for that
property (1 for years, months, days, 0 for hours, minutes, seconds).
Call the function.
For each property
absent
in the initial value,
set the corresponding property in the result value to
absent
Examples:
dateTime
duration
result
2000-01-12T12:13:14Z
P1Y3M5DT7H10M3.3S
2001-04-17T19:23:17.3Z
2000-01
-P3M
1999-10
2000-01-12
PT33H
2000-01-13
Note that the addition defined by
dateTimePlusDuration
differs from addition on
integers or real numbers in not being commutative.
The order of addition of durations to instants
is
significant.
For example, there are cases where:
((dateTime + duration1) + duration2) != ((dateTime +
duration2) + duration1)
Example:
(2000-03-30 + P1D) + P1M = 2000-03-31 + P1M = 2000-
04-30
(2000-03-30 + P1M) + P1D = 2000-04-30 + P1D = 2000-
05-01
E.3.4 Time on timeline
Time on Timeline for Date/time Seven-property
Model Datatypes
timeOnTimeline
dt
) → decimal number
Maps a
date/timeSevenPropertyModel
value to the decimal number
representing its position on the "time line".
Arguments:
dt
date/timeSevenPropertyModel
value
Result:
a decimal number
Algorithm:
Let
yr
be
1971
when
dt
's
year
is
absent
and
dt
's
year
− 1 otherwise,
mo
be 12 or
dt
's
month
, similarly,
da
be
daysInMonth
yr
+1,
mo
) − 1
or (
dt
's
day
) − 1 , similarly,
hr
be 0 or
dt
's
hour
similarly,
mi
be 0 or
dt
's
minute
similarly,
and
se
be 0 or
dt
's
second
similarly.
Subtract
timezoneOffset
from
mi
when
timezoneOffset
is not
absent
year
Set
ToTl
to
31536000 ×
yr
(Leap-year Days,
month
, and
day
Add 86400 ×
yr
div
400 −
yr
div
100 +
yr
div
4) to
ToTl
Add 86400 × Sum
mo
daysInMonth
yr
+ 1,
) to
ToTl
Add 86400 ×
da
to
ToTl
hour
minute
and
second
Add 3600 ×
hr
60 ×
mi
se
to
ToTl
Return
ToTl
E.3.5 Lexical mappings
Partial Date/time Lexical Mappings
yearFragValue
YR
) → integer
Maps a
yearFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
year
property of a
date/timeSevenPropertyModel
value.
Arguments:
YR
matches
yearFrag
Result:
an integer
Algorithm:
Return
noDecimalMap
YR
monthFragValue
MO
) → integer
Maps a
monthFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
month
property of a
date/timeSevenPropertyModel
value.
Arguments:
MO
matches
monthFrag
Result:
an integer
Algorithm:
Return
unsignedNoDecimalMap
MO
dayFragValue
DA
) → integer
Maps a
dayFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
day
property of a
date/timeSevenPropertyModel
value.
Arguments:
DA
matches
dayFrag
Result:
an integer
Algorithm:
Return
unsignedNoDecimalMap
DA
hourFragValue
HR
) → integer
Maps a
hourFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
hour
property of a
date/timeSevenPropertyModel
value.
Arguments:
HR
matches
hourFrag
Result:
an integer
Algorithm:
Return
unsignedNoDecimalMap
HR
minuteFragValue
MI
) → integer
Maps a
minuteFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
minute
property of a
date/timeSevenPropertyModel
value.
Arguments:
MI
matches
minuteFrag
Result:
an integer
Algorithm:
Return
unsignedNoDecimalMap
MI
secondFragValue
SE
) → decimal number
Maps a
secondFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto a decimal number, presumably the
second
property of a
date/timeSevenPropertyModel
value.
Arguments:
SE
matches
secondFrag
Result:
a decimal number
Algorithm:
Return
unsignedNoDecimalMap
SE
) when no decimal point occurs in
SE
, and
unsignedDecimalPtMap
SE
) otherwise.
timezoneFragValue
TZ
) → integer
Maps a
timezoneFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
onto an integer, presumably the
timezoneOffset
property of a
date/timeSevenPropertyModel
value.
Arguments:
TZ
matches
timezoneFrag
Result:
an integer
Algorithm:
TZ
necessarily consists of either just '
', or
a sign ('
' or '
') followed by an instance
of
hourFrag
, a colon, and an instance
of
minuteFrag
Return
0 when
TZ
is '
',
−(
unsignedDecimalPtMap
) × 60 +
unsignedDecimalPtMap
))
when the sign is '
', and
unsignedDecimalPtMap
) × 60 +
unsignedDecimalPtMap
otherwise.
Note:
There is no
lexical mapping
for
endOfDayFrag
; it is handled specially by the relevant
lexical mappings
. See, e.g.,
dateTimeLexicalMap
Lexical Mapping
dateTimeLexicalMap
LEX
) →
dateTime
Maps a
dateTimeLexicalRep
to
dateTime
value.
Arguments:
LEX
matches
dateTimeLexicalRep
Result:
a complete
dateTime
value
Algorithm:
LEX
necessarily includes
substrings
that are instances of
yearFrag
monthFrag
, and
dayFrag
(below referred to as
MO
, and
respectively);
it
also contains either instances of
hourFrag
minuteFrag
and
secondFrag
MI
, and
),
or
else an instance of
endOfDayFrag
; finally,
it may optionally contain an instance
of
timezoneFrag
).
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
yearFragValue
),
monthFragValue
MO
),
dayFragValue
), 24, 0, 0,
tz
) when
endOfDayFrag
is present, and
newDateTime
yearFragValue
),
monthFragValue
MO
),
dayFragValue
),
hourFragValue
),
minuteFragValue
MI
),
secondFragValue
),
tz
) otherwise
Lexical Mapping
timeLexicalMap
LEX
) →
time
Maps a
timeLexicalRep
to
time
value.
Arguments:
LEX
matches
timeLexicalRep
Result:
a complete
time
value
Algorithm:
LEX
necessarily includes
either
substrings that are instances of
hourFrag
minuteFrag
and
secondFrag
, (below referred to as
, and
respectively), or
else an instance of
endOfDayFrag
; finally, it may optionally contain
an instance of
timezoneFrag
).
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
absent
absent
absent
, 0, 0, 0,
tz
) when
endOfDayFrag
is present, and
newDateTime
absent
absent
absent
hourFragValue
),
minuteFragValue
MI
),
secondFragValue
),
tz
) otherwise.
Lexical Mapping
dateLexicalMap
LEX
) →
date
Maps a
dateLexicalRep
to a
date
value.
Arguments:
LEX
matches
dateLexicalRep
Result:
a complete
date
value
Algorithm:
LEX
necessarily includes
an instance
of
yearFrag
an instance
of
monthFrag
and an instance
of
dayFrag
hyphen-separated and optionally followed by an instance
of
timezoneFrag
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
yearFragValue
),
monthFragValue
),
dayFragValue
),
absent
absent
absent
tz
.)
Lexical Mapping
gYearMonthLexicalMap
LEX
) →
gYearMonth
Maps a
gYearMonthLexicalRep
to a
gYearMonth
value.
Arguments:
LEX
matches
gYearMonthLexicalRep
Result:
a complete
gYearMonth
value
Algorithm:
LEX
necessarily includes
an instance
of
yearFrag
and an instance
of
monthFrag
hyphen-separated and optionally followed by an instance
of
timezoneFrag
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
yearFragValue
),
monthFragValue
),
absent
absent
absent
absent
tz
).
Lexical Mapping
gYearLexicalMap
LEX
) →
gYear
Maps a
gYearLexicalRep
to
gYear
value.
Arguments:
LEX
matches
gYearLexicalRep
Result:
a complete
gYear
value
Algorithm:
LEX
necessarily includes
an instance
of
yearFrag
optionally followed by an instance
of
timezoneFrag
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
yearFragValue
),
absent
absent
absent
absent
absent
tz
).
Lexical Mapping
gMonthDayLexicalMap
LEX
) →
gMonthDay
Maps a
gMonthDayLexicalRep
to a
gMonthDay
value.
Arguments:
LEX
matches
gMonthDayLexicalRep
Result:
a complete
gMonthDay
value
Algorithm:
LEX
necessarily includes
an instance
of
monthFrag
and an instance
of
dayFrag
hyphen-separated and optionally followed by an instance
of
timezoneFrag
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
absent
monthFragValue
),
dayFragValue
),
absent
absent
absent
tz
Lexical Mapping
gDayLexicalMap
LEX
) →
gDay
Maps a
gDayLexicalRep
to
gDay
value.
Arguments:
LEX
matches
gDayLexicalRep
Result:
a complete
gDay
value
Algorithm:
LEX
necessarily includes
an instance
of
dayFrag
optionally followed by an instance
of
timezoneFrag
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
gD
absent
absent
dayFragValue
),
absent
absent
absent
tz
).
Return
newDateTime
absent
absent
dayFragValue
),
absent
absent
absent
tz
).
Lexical Mapping
gMonthLexicalMap
LEX
) →
gMonth
Maps a
gMonthLexicalRep
to
gMonth
value.
Arguments:
LEX
matches
gMonthLexicalRep
Result:
a complete
gMonth
value
Algorithm:
LEX
necessarily includes
an instance
of
monthFrag
optionally followed by an instance
of
timezoneFrag
Let
tz
be
timezoneFragValue
) when
is present, otherwise
absent
Return
newDateTime
absent
monthFragValue
),
absent
absent
absent
absent
tz
E.3.6 Canonical Mappings
Auxiliary Functions for Date/time Canonical Mappings
unsTwoDigitCanonicalFragmentMap
) →
unsignedNoDecimalPtNumeral
Maps a nonnegative integer less than 100 onto an unsigned always-two-digit numeral.
Arguments:
a nonnegative integer less than 100
Result:
matches
unsignedNoDecimalPtNumeral
Algorithm:
Return
digit
div
10) &
digit
mod
10)
fourDigitCanonicalFragmentMap
) →
noDecimalPtNumeral
Maps an integer between -10000 and 10000 onto an always-four-digit numeral.
Arguments:
an integer whose absolute value is less than 10000
Result:
matches
noDecimalPtNumeral
Algorithm:
Return
' &
unsTwoDigitCanonicalFragmentMap
(−
div
100) &
unsTwoDigitCanonicalFragmentMap
(−
mod
100) when
is negative,
unsTwoDigitCanonicalFragmentMap
div
100) &
unsTwoDigitCanonicalFragmentMap
mod
100) otherwise.
Partial Date/time Canonical Mappings
yearCanonicalFragmentMap
) →
yearFrag
Maps an integer, presumably the
year
property of a
date/timeSevenPropertyModel
value,
onto a
yearFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
Arguments:
an integer
Result:
matches
yearFrag
Algorithm:
Return
noDecimalPtCanonicalMap
) when |
| > 9999 .
fourDigitCanonicalFragmentMap
) otherwise.
monthCanonicalFragmentMap
) →
monthFrag
Maps an integer, presumably the
month
property of a
date/timeSevenPropertyModel
value,
onto a
monthFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
Arguments:
an integer between 1 and 12 inclusive
Result:
matches
monthFrag
Algorithm:
Return
unsTwoDigitCanonicalFragmentMap
dayCanonicalFragmentMap
) →
dayFrag
Maps an integer, presumably the
day
property of a
date/timeSevenPropertyModel
value,
onto a
dayFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
Arguments:
an integer between 1 and 31 inclusive
(may be limited further depending on associated
year
and
month
Result:
matches
dayFrag
Algorithm:
Return
unsTwoDigitCanonicalFragmentMap
hourCanonicalFragmentMap
) →
hourFrag
Maps an integer, presumably the
hour
property of a
date/timeSevenPropertyModel
value,
onto a
hourFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
Arguments:
an integer between 0 and 23 inclusive.
Result:
matches
hourFrag
Algorithm:
Return
unsTwoDigitCanonicalFragmentMap
minuteCanonicalFragmentMap
) →
minuteFrag
Maps an integer, presumably the
minute
property of a
date/timeSevenPropertyModel
value,
onto a
minuteFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
Arguments:
an integer between 0 and 59 inclusive.
Result:
matches
minuteFrag
Algorithm:
Return
unsTwoDigitCanonicalFragmentMap
secondCanonicalFragmentMap
) →
secondFrag
Maps a decimal number, presumably the
second
property of a
date/timeSevenPropertyModel
value,
onto a
secondFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
Arguments:
a nonnegative decimal number less than 70
Result:
matches
secondFrag
Algorithm:
Return
unsTwoDigitCanonicalFragmentMap
when
is an integer, and
unsTwoDigitCanonicalFragmentMap
div
1) &
' &
fractionDigitsCanonicalFragmentMap
mod
1)
otherwise.
timezoneCanonicalFragmentMap
) →
timezoneFrag
Maps an integer, presumably the
timezoneOffset
property of a
date/timeSevenPropertyModel
value,
onto a
timezoneFrag
, part of a
date/timeSevenPropertyModel
's
lexical representation
Arguments:
an integer between −840 and 840 inclusive
Result:
matches
timezoneFrag
Algorithm:
Return
' when
is zero,
' &
unsTwoDigitCanonicalFragmentMap
(−
div
60) &
' &
unsTwoDigitCanonicalFragmentMap
(−
mod
60) when
is negative, and
' &
unsTwoDigitCanonicalFragmentMap
div
60) &
' &
unsTwoDigitCanonicalFragmentMap
mod
60) otherwise.
Canonical Mapping
dateTimeCanonicalMap
dt
) →
dateLexicalRep
Maps a
dateTime
value to a
dateTimeLexicalRep
Arguments:
dt
a complete
dateTime
value
Result:
matches
dateLexicalRep
Algorithm:
Let
DT
be
yearCanonicalFragmentMap
dt
's
year
) &
' &
monthCanonicalFragmentMap
dt
's
month
) &
' &
dayCanonicalFragmentMap
dt
's
day
) &
' &
hourCanonicalFragmentMap
dt
's
hour
) &
' &
minuteCanonicalFragmentMap
dt
's
minute
) &
' &
secondCanonicalFragmentMap
dt
's
second
) .
Return
DT
when
dt
's
timezoneOffset
is
absent
, and
DT
timezoneCanonicalFragmentMap
dt
's
timezoneOffset
) otherwise.
Canonical Mapping
timeCanonicalMap
ti
) →
timeLexicalRep
Maps a
time
value to a
timeLexicalRep
Arguments:
ti
a complete
time
value
Result:
matches
timeLexicalRep
Algorithm:
Let
be
hourCanonicalFragmentMap
ti
's
hour
) &
' &
minuteCanonicalFragmentMap
ti
's
minute
) &
' &
secondCanonicalFragmentMap
ti
's
second
) .
Return
when
ti
's
timezoneOffset
is
absent
, and
timezoneCanonicalFragmentMap
ti
's
timezoneOffset
) otherwise.
Canonical Mapping
dateCanonicalMap
da
) →
dateLexicalRep
Maps a
date
value to a
dateLexicalRep
Arguments:
da
a complete
date
value
Result:
matches
dateLexicalRep
Algorithm:
Let
be
yearCanonicalFragmentMap
da
's
year
) &
' &
monthCanonicalFragmentMap
da
's
month
) &
' &
dayCanonicalFragmentMap
da
's
day
) .
Return
when
da
's
timezoneOffset
is
absent
, and
timezoneCanonicalFragmentMap
da
's
timezoneOffset
otherwise.
Canonical Mapping
gYearMonthCanonicalMap
ym
) →
gYearMonthLexicalRep
Maps a
gYearMonth
value to a
gYearMonthLexicalRep
Arguments:
ym
a complete
gYearMonth
value
Result:
matches
gYearMonthLexicalRep
Algorithm:
Let
YM
be
yearCanonicalFragmentMap
ym
's
year
) &
' &
monthCanonicalFragmentMap
ym
's
month
) .
Return
YM
when
ym
's
timezoneOffset
is
absent
, and
YM
timezoneCanonicalFragmentMap
ym
's
timezoneOffset
otherwise.
Canonical Mapping
gYearCanonicalMap
gY
) →
gYearLexicalRep
Maps a
gYear
value to a
gYearLexicalRep
Arguments:
gY
a complete
gYear
value
Result:
matches
gYearLexicalRep
Algorithm:
Return
yearCanonicalFragmentMap
gY
's
year
when
gY
's
timezoneOffset
is
absent
, and
yearCanonicalFragmentMap
gY
's
year
) &
timezoneCanonicalFragmentMap
gY
's
timezoneOffset
otherwise.
Canonical Mapping
gMonthDayCanonicalMap
md
) →
gMonthDayLexicalRep
Maps a
gMonthDay
value to a
gMonthDayLexicalRep
Arguments:
md
a complete
gMonthDay
value
Result:
matches
gMonthDayLexicalRep
Algorithm:
Let
MD
be '
--
' &
monthCanonicalFragmentMap
md
's
month
) &
' &
dayCanonicalFragmentMap
md
's
day
) .
Return
MD
when
md
's
timezoneOffset
is
absent
, and
MD
timezoneCanonicalFragmentMap
md
's
timezoneOffset
otherwise.
Canonical Mapping
gDayCanonicalMap
gD
) →
gDayLexicalRep
Maps a
gDay
value to a
gDayLexicalRep
Arguments:
gD
a complete
gDay
value
Result:
matches
gDayLexicalRep
Algorithm:
Return
---
' &
dayCanonicalFragmentMap
gD
's
day
when
gD
's
timezoneOffset
is
absent
, and
---
' &
dayCanonicalFragmentMap
gD
's
day
) &
timezoneCanonicalFragmentMap
gD
's
timezoneOffset
otherwise.
Canonical Mapping
gMonthCanonicalMap
gM
) →
gMonthLexicalRep
Maps a
gMonth
value to a
gMonthLexicalRep
Arguments:
gM
a complete
gMonth
value
Result:
matches
gMonthLexicalRep
Algorithm:
Return
--
' &
monthCanonicalFragmentMap
gM
's
day
when
gM
's
timezoneOffset
is
absent
, and
--
' &
monthCanonicalFragmentMap
gM
's
day
) &
timezoneCanonicalFragmentMap
gM
's
timezoneOffset
otherwise.
E.4 Lexical and Canonical Mappings for Other Datatypes
The following functions are used with various datatypes neither numeric
nor date/time related.
Lexical Mapping
stringLexicalMap
LEX
) →
string
Maps a
literal
matching the
stringRep
production to
string
value.
Arguments:
LEX
literal
matching
stringRep
Result:
string
value
Algorithm:
Return
LEX
. (The function is the identity
function on the domain.)
Lexical Mapping
booleanLexicalMap
LEX
) →
boolean
Maps a
literal
matching the
booleanRep
production to
boolean
value.
Arguments:
LEX
literal
matching
booleanRep
Result:
boolean
value
Algorithm:
Return
true
when
LEX
is '
true
or '
' , and
false
otherwise (
LEX
is '
false
or '
').
Canonical Mapping
stringCanonicalMap
) →
stringRep
Maps a
string
value to
stringRep
Arguments:
string
value
Result:
matches
stringRep
Algorithm:
Return
. (The function is the identity
function on the domain.)
Canonical Mapping
booleanCanonicalMap
) →
booleanRep
Maps a
boolean
value to
booleanRep
Arguments:
boolean
value
Result:
matches
booleanRep
Algorithm:
Return
true
' when
is
true
, and
false
' otherwise (
is
false
).
E.4.1 Lexical and canonical mappings for
hexBinary
The
lexical mapping
for
hexBinary
maps each pair of hexadecimal digits to an octet, in the conventional way:
Lexical Mapping for hexBinary
hexBinaryMap
LEX
) →
hexBinary
Maps a
literal
matching the
hexBinary
production to
a sequence of octets in the form of a
hexBinary
value.
Arguments:
LEX
literal
matching
hexBinary
Result:
A sequence of binary octets in the form of a
hexBinary
value
Algorithm:
LEX
necessarily includes a sequence of zero or more
substrings matching the
hexOctet
production.
Let
be the sequence of octets formed by applying
hexOctetMap
to each
hexOctet
in
LEX
, in order, and concatenating the results.
Return
The auxiliary functions
hexOctetMap
and
hexDigitMap
are used by
hexBinaryMap
Mappings for hexadecimal digits
hexOctetMap
LEX
) → octet
Maps a
literal
matching the
hexOctet
production to
a single octet.
Arguments:
LEX
literal
matching
hexOctet
Result:
A single binary octet
Algorithm:
LEX
necessarily includes exactly two hexadecimal digits.
Let
d0
be the first hexadecimal digit in
LEX
Let
d1
be the second hexadecimal digit in
LEX
Return the octet whose four high-order bits are
hexDigitMap
d0
) and whose four low-order bits
are
hexDigitMap
d1
).
hexDigitMap
) → a bit-sequence of length four
Maps a hexadecimal digit (a character matching
the
hexDigit
production) to
a sequence of four binary digits.
Arguments:
a hexadecimal digit
Result:
a sequence of four binary digits
Algorithm:
Return
0000 when
= '
',
0001 when
= '
',
0010 when
= '
',
0011 when
= '
',
...
1110 when
= '
' or '
',
1111 when
= '
' or '
'.
The
canonical mapping
for
hexBinary
uses only the
uppercase forms of A-F.
Canonical Mapping for hexBinary
hexBinaryCanonical
) →
hexBinary
Maps a
hexBinary
value to a literal
matching the
hexBinary
production.
Arguments:
hexBinary
value
Result:
matches
hexBinary
Algorithm:
Let
be the sequence of literals formed by applying
hexOctetCanonical
to each octet in
, in order, and concatenating the results.
Return
Auxiliary procedures for canonical mapping of
hexBinary
hexOctetCanonical
) →
hexOctet
Maps a binary octet to a literal
matching the
hexOctet
production.
Arguments:
a binary octet
Result:
matches
hexOctet
Algorithm:
Let
lo
be the four low-order bits of
and
hi
be the four high-order bits.
Return
hexDigitCanonical
hi
) &
hexDigitCanonical
lo
).
hexDigitCanonical
) →
hexDigit
Maps a four-bit sequence to a hexadecimal
digit (a literal
matching the
hexDigit
production).
Arguments:
a sequence of four binary digits
Result:
matches
hexDigit
Algorithm:
Return
' when
= 0000,
' when
= 0001,
' when
= 0010,
' when
= 0011,
...
' when
= 1110,
' when
= 1111.
F Datatypes and Facets
F.1 Fundamental Facets
The following table shows the values of the fundamental facets
for each
built-in
datatype.
Datatype
ordered
bounded
cardinality
numeric
primitive
string
false
false
countably infinite
false
boolean
false
false
finite
false
float
partial
true
finite
true
double
partial
true
finite
true
decimal
total
false
countably infinite
true
duration
partial
false
countably infinite
false
dateTime
partial
false
countably infinite
false
time
partial
false
countably infinite
false
date
partial
false
countably infinite
false
gYearMonth
partial
false
countably infinite
false
gYear
partial
false
countably infinite
false
gMonthDay
partial
false
countably infinite
false
gDay
partial
false
countably infinite
false
gMonth
partial
false
countably infinite
false
hexBinary
false
false
countably infinite
false
base64Binary
false
false
countably infinite
false
anyURI
false
false
countably infinite
false
QName
false
false
countably infinite
false
NOTATION
false
false
countably infinite
false
non-primitive
normalizedString
false
false
countably infinite
false
token
false
false
countably infinite
false
language
false
false
countably infinite
false
IDREFS
false
false
countably infinite
false
ENTITIES
false
false
countably infinite
false
NMTOKEN
false
false
countably infinite
false
NMTOKENS
false
false
countably infinite
false
Name
false
false
countably infinite
false
NCName
false
false
countably infinite
false
ID
false
false
countably infinite
false
IDREF
false
false
countably infinite
false
ENTITY
false
false
countably infinite
false
integer
total
false
countably infinite
true
nonPositiveInteger
total
false
countably infinite
true
negativeInteger
total
false
countably infinite
true
long
total
true
finite
true
int
total
true
finite
true
short
total
true
finite
true
byte
total
true
finite
true
nonNegativeInteger
total
false
countably infinite
true
unsignedLong
total
true
finite
true
unsignedInt
total
true
finite
true
unsignedShort
total
true
finite
true
unsignedByte
total
true
finite
true
positiveInteger
total
false
countably infinite
true
yearMonthDuration
partial
false
countably infinite
false
dayTimeDuration
partial
false
countably infinite
false
dateTimeStamp
partial
false
countably infinite
false
G Regular Expressions
regular expression
is a sequence of
characters that denote a
set
of strings
).
When used to constrain a
lexical space
, a
regular
expression
asserts that only strings in
are valid
literals
for values of that type.
Note:
Unlike some popular regular expression languages (including those
defined by Perl and standard Unix utilities), the regular
expression language defined here implicitly anchors all regular
expressions at the head and tail, as the most common use of
regular expressions in
pattern
is to match entire
literals
For example, a datatype
derived
from
string
such
that all values must begin with the character
(#x41) and end with the character
(#x5a) would be defined as follows:
In regular expression languages that are not implicitly anchored at the head and tail,
it is customary to write the equivalent regular expression as:
^A.*Z$
where
anchors the pattern at the head and
anchors at the tail.
In those rare cases where an unanchored match is desired, including
.*
at the beginning and ending of the regular expression will
achieve the desired results. For example, a datatype
derived
from string
such that all values must contain at least 3 consecutive
(#x41)
characters somewhere within the value could be defined as follows:
G.1 Regular expressions and branches
[Definition:]
regular expression
is composed from zero or more
branches
separated by
characters.
Regular Expression
[64]
regExp
::=
branch
( '|'
branch
)*
For all
branches
, and for all
regular
expressions
, valid
regular
expressions
are:
Denoting the set of strings
containing:
(empty string)
just the empty string
all strings in
all strings in
and all strings in
[Definition:]
branch
consists of zero or more
pieces
concatenated together.
Branch
[65]
branch
::=
piece
For all
pieces
, and for all
branches
, valid
branches
are:
Denoting the set of strings
containing:
all strings in
all strings
with
in
and
in
G.2 Pieces, atoms, quantifiers
[Definition:]
piece
is an
atom
, possibly followed by a
quantifier
Piece
[66]
piece
::=
atom
quantifier
For all
atoms
and non-negative
integers
such that
, valid
pieces
are:
Denoting the set of strings
containing:
all strings in
the empty string, and all strings in
all strings in
and all strings
with
in
and
in
(all concatenations of zero or more strings from
) )
all strings
with
in
and
in
(all concatenations of one or more strings from
) )
all strings
with
in
and
in
−1
−1
(all
concatenations
of at least
and at most
strings from
) )
all
strings in
(all
concatenations
of exactly
strings from
) )
,}
all
strings in
(all
concatenations
of at least
strings from
) )
{0,
all strings
with
in
and
in
−1
).
(all
concatenations
of at most
strings from
) )
{0,0}
only the empty string
Note:
The regular expression language in the Perl Programming Language
[Perl]
does not include a quantifier of the form
{,
since it is logically equivalent to
{0,
We have, therefore, left this logical possibility out of the regular
expression language defined by this specification.
[Definition:]
quantifier
is one of
',
', or '
', or a string of the form
or
,}
which have the meanings
defined in the table above.
Quantifier
[67]
quantifier
::=
[?*+] | ( '{'
quantity
'}' )
[68]
quantity
::=
quantRange
quantMin
QuantExact
[69]
quantRange
::=
QuantExact
','
QuantExact
[70]
quantMin
::=
QuantExact
','
[71]
QuantExact
::=
[0-9]+
[Definition:]
An
atom
is either a
normal character
, a
character class
, or
a parenthesized
regular expression
Atom
[72]
atom
::=
NormalChar
charClass
| ( '('
regExp
')' )
For all
normal
characters
character
classes
, and
regular
expressions
, valid
atoms
are:
Denoting the set of strings
containing:
the single string consisting only of
all strings in
G.3 Characters and metacharacters
[Definition:]
metacharacter
is either
',
', '
', '
',
', '
', '
',
', '
',
',
',
or '
'.
These characters have special meanings in
regular
expressions
, but can be escaped to form
atoms
that denote the sets of strings containing only themselves, i.e., an escaped
metacharacter
behaves like a
normal character
[Definition:]
normal character
is any XML character that is not a
metacharacter
In
regular
expressions
, a
normal
character
is an
atom
that denotes the singleton set of strings containing only itself.
Normal Character
[73]
NormalChar
::=
[^.\?*+{}()|#x5B#x5D]
/* N.B.: #x5B = '
',
#x5D = '
' */
G.4 Character Classes
G.4.1
Character class expressions
G.4.2
Character Class Escapes
G.4.2.1
Single-character escapes
G.4.2.2
Category escapes
G.4.2.3
Block escapes
G.4.2.4
Unrecognized category escapes
G.4.2.5
Multi-character escapes
[Definition:]
character class
is an
atom
that identifies a
set
of characters
).
The set of strings
).
denoted by a character class
contains one single-character
string "
" for each character
in
).
Character Class
[74]
charClass
::=
SingleCharEsc
charClassEsc
charClassExpr
WildcardEsc
A character class is either
single-character escape
or
character class escape
or a
character class expression
or
wildcard character
Note:
The rules for which characters must be escaped and which
can represent themselves are different when inside a
character class expression
; some
normal characters
must be escaped and some
metacharacters
need
not be.
G.4.1 Character class expressions
[Definition:]
character class expression
charClassExpr
is a
character group
surrounded by
and
characters. For all character groups
is a valid
character class
expression
, identifying the set of characters
).
Character Class Expression
[75]
charClassExpr
::=
'['
charGroup
']'
[Definition:]
character group
charGroup
) starts
with either a
positive character group
or
negative character group
and is optionally followed by a subtraction operator '
and a further
character class expression
[Definition:]
character group
that contains a subtraction operator
is referred to as a
character class subtraction
Character Group
[76]
charGroup
::=
posCharGroup
negCharGroup
( '-'
charClassExpr
)?
If the first character in a
charGroup
is '
', this is
taken as indicating that the
charGroup
starts with a
negCharGroup
posCharGroup
can itself start with '
' but only when it
appears within a
negCharGroup
, that is, when the
' is preceded by another '
'.
Note:
For example, the string
[^X]
is ambiguous according the grammar rules, denoting either
a character class consisting of a negative character group
with
as a member, or
a positive character class with
and
as members. The
normative prose rule just given requires that the
first interpretation be taken.
The string
[^]
is unambiguous: the grammar recognizes it as
a character class expression
containing
a positive
character group containing just
the character
'.
But the grammatical derivation of the string violates
the rule just given, so the string
[^]
must not
be accepted as a regular expression.
A '
' character
is recognized as a subtraction operator
(and hence, as terminating the
posCharGroup
or
negCharGroup
) if it is immediately followed by a '
character.
For any
positive character group
or
negative character group
, and any
character class expression
is a valid
character group
, identifying the set of all characters in
that are not in
).
[Definition:]
positive character group
consists of one or more
character group parts
, concatenated
together. The
set of characters identified by a
positive character group
is
the union of all of the sets identified
by its constituent
character group
parts
Positive Character Group
[77]
posCharGroup
::=
charGroupPart
)+
For all
character
ranges
, all
character class
escapes
and all
positive character groups
, valid
positive
charater groups
are:
Identifying the set of characters
containing:
all characters in
all characters in
all characters in
and all characters in
all characters in
and all characters in
[Definition:]
negative character group
negCharGroup
consists of a
character
followed by a
positive character group
The set of characters identified by
a negative character group
is
the set of all
characters that are
not
in
).
Negative Character Group
[78]
negCharGroup
::=
'^'
posCharGroup
[Definition:]
character group part
charGroupPart
) is
any
of:
a single unescaped character
SingleCharNoEsc
),
a single escaped character
SingleCharEsc
),
a character class escape
charClassEsc
),
or a character range
charRange
).
Character Group Part
[79]
charGroupPart
::=
singleChar
charRange
charClassEsc
[80]
singleChar
::=
SingleCharEsc
SingleCharNoEsc
If a
charGroupPart
starts with a
singleChar
and this is immediately followed by a hyphen,
then
the following rules apply.
If the hyphen is immediately followed by '
',
then the hyphen is not part of the
charGroupPart
instead, it is recognized as a character-class subtraction operator.
If the hyphen is immediately followed by '
',
then the hyphen is recognized as a
singleChar
and
is part of the
charGroupPart
If the hyphen is immediately followed by '
-[
',
then the hyphen is recognized as a
singleChar
and
is part of the
charGroupPart
Otherwise, the hyphen
must
be immediately followed by some
singleChar
other than a hyphen. In this case
the hyphen is not part of the
charGroupPart
instead it is recognized, together with the immediately
preceding and following instances of
singleChar
as a
charRange
If the hyphen is followed by any other character sequence,
then the string in which it occurs
is not recognized as a regular expression.
It is an error if either of the two
singleChar
s in a
charRange
is a
SingleCharNoEsc
comprising an unescaped hyphen.
Note:
The rule just given resolves what would otherwise
be the ambiguous
interpretation
of some strings, e.g.
[a-k-z]
';
it also constrains regular expressions in ways
not expressed in the grammar. For example, the
rule (not the grammar) excludes the string
[--z]
from the
regular expression language defined here.
[Definition:]
character range
identifies a set of
characters
with UCS code points in a specified range.
Character Range
[81]
charRange
::=
singleChar
'-'
singleChar
character range
in the form
identifies
the set
of
characters
with UCS code points greater than or equal to the code point
of
, but not greater than the code point of
Single Unescaped Character
[82]
SingleCharNoEsc
::=
[^\#x5B#x5D]
/* N.B.:
#x5B = '
',
#x5D = '
' */
A single unescaped character
SingleCharNoEsc
) is any character
except '
' or '
'.
There are special rules, described earlier, that
constrain
the use of the characters '
' and
' in order to disambiguate the syntax.
A single unescaped character
identifies the singleton set of characters containing
that character alone.
A single escaped character
SingleCharEsc
), when used within a
character group, identifies the singleton set of characters
containing the character denoted by the
escape (see
Character Class Escapes (§G.4.2)
).
G.4.2 Character Class Escapes
[Definition:]
character class escape
is a short sequence of characters
that identifies a predefined
character class. The valid character class escapes are
the
multi-character escapes
, and the
category escapes
(including the
block escapes
).
Character Class Escape
[83]
charClassEsc
::=
MultiCharEsc
catEsc
complEsc
G.4.2.1 Single-character escapes
Closely related to the
character-class escapes are the single-character escapes.
[Definition:]
single-character escape
identifies a set containing
only one
character—usually
because that character is difficult or
impossible to write directly into a
regular expression
Single Character Escape
[84]
SingleCharEsc
::=
'\' [nrt\|.?*+(){}#x2D#x5B#x5D#x5E]
/* N.B.:
#x2D = '
', #x5B = '
', #x5D =
', #x5E = '
' */
The valid
single
character escapes
are:
Identifying the set of characters
containing:
\n
the newline character (#xA)
\r
the return character (#xD)
\t
the tab character (#x9)
\\
\|
\.
\-
\^
\?
\*
\+
\{
\}
\(
\)
\[
\]
G.4.2.2 Category escapes
[Definition:]
[Unicode Database]
specifies a number of possible values for
the "General Category" property and provides mappings
from code points to specific character properties.
The set containing all characters that have property
can be identified with a
category escape
\p{
(using a lower-case
'p').
The complement of this set is specified with the
category
escape
\P{
(using an upper-case 'P').
For all
, if
is a recognized
character-property code, then
[\P{
}]
[^\p{
}]
Category Escape
[85]
catEsc
::=
'\p{'
charProp
'}'
[86]
complEsc
::=
'\P{'
charProp
'}'
[87]
charProp
::=
IsCategory
IsBlock
[Unicode Database]
is subject to future revision. For
example, the mapping from code points to character properties might be
updated. All
minimally conforming
processors
must
support the character properties defined in
the version of
[Unicode Database]
cited in the
normative references (
Normative (§K.1)
) or in
some later version of the Unicode database. Implementors are encouraged to support the
character properties defined in any later versions. When the
implementation supports multiple versions of the Unicode database, and
they differ in salient respects (e.g. different properties are
assigned to the same character in different versions of the database),
then it is
implementation-defined
which set of property definitions is used
for any given assessment episode.
Note:
In order to benefit from continuing work on the Unicode database,
a conforming implementation might by default use the latest supported
version of the character properties. In order to maximize consistency
with other implementations of this specification, however, an
implementation might choose to provide
user options
to specify the
use of the version of the database cited in the normative references.
The
PropertyAliases.txt
and
PropertyValueAliases.txt
files of
the Unicode database may be helpful to implementors in this connection.
For convenience, the following table lists
the values of the "General Category" property in the
version
of
[Unicode Database]
cited in the normative references
Normative (§K.1)
).
The properties with single-character names are not defined in
[Unicode Database]
. The value of a single-character
property is the union of the values of all the two-character properties
whose first character is the character in question. For example,
for
, the union of
Nd
Nl
and
No
Note:
As of this publication the Java regex
library does
not
include
Cn
in its definition of
, so that definition cannot be used without modification
in conformant implementations.
Category
Property
Meaning
Letters
All Letters
Lu
uppercase
Ll
lowercase
Lt
titlecase
Lm
modifier
Lo
other
Marks
All Marks
Mn
nonspacing
Mc
spacing combining
Me
enclosing
Numbers
All Numbers
Nd
decimal digit
Nl
letter
No
other
Punctuation
All Punctuation
Pc
connector
Pd
dash
Ps
open
Pe
close
Pi
initial quote
(may behave like Ps or Pe depending on usage)
Pf
final quote
(may behave like Ps or Pe depending on usage)
Po
other
Separators
All Separators
Zs
space
Zl
line
Zp
paragraph
Symbols
All Symbols
Sm
math
Sc
currency
Sk
modifier
So
other
Other
All Others
Cc
control
Cf
format
Co
private use
Cn
not assigned
Categories
[88]
IsCategory
::=
Letters
Marks
Numbers
Punctuation
Separators
Symbols
Others
[89]
Letters
::=
'L' [ultmo]?
[90]
Marks
::=
'M' [nce]?
[91]
Numbers
::=
'N' [dlo]?
[92]
Punctuation
::=
'P' [cdseifo]?
[93]
Separators
::=
'Z' [slp]?
[94]
Symbols
::=
'S' [mcko]?
[95]
Others
::=
'C' [cfon]?
Note:
The properties mentioned above exclude the Cs property. The Cs property identifies
"surrogate" characters, which do not occur at the
level of the "character abstraction" that XML
instance documents operate on.
G.4.2.3 Block escapes
[Unicode Database]
groups the code points of the Universal
Character Set (UCS) into a number of blocks such as Basic Latin (i.e.,
ASCII), Latin-1 Supplement, Hangul Jamo, CJK Compatibility, etc.
The block-escape construct allows regular expressions to refer to sets
of characters by the name of the block in which they appear, using a
normalized block name
[Definition:]
For any Unicode block, the
normalized block name
of that
block is the string of characters formed by stripping out white space
and underbar characters from the block name as given in
[Unicode Database]
, while retaining hyphens and preserving case
distinctions.
[Definition:]
block escape
expression denotes the set of characters
in a given Unicode block. For any Unicode block
, with
normalized block name
, the set containing all
characters defined in block
can be identified with the
block
escape
\p{Is
(using lower-case
'p'). The complement of this set is denoted by the
block escape
\P{Is
(using upper-case
'P'). For all
, if
is a normalized block name
recognized by the processor, then
[\P{Is
}]
[^\p{Is
}]
Block Escape
[96]
IsBlock
::=
'Is' [a-zA-Z0-9#x2D]+
/* N.B.:
#x2D = '
' */
block escape
\p{IsBasicLatin}
Note:
Current versions of the Unicode database recommend that whenever
block names are being matched hyphens, underbars, and white space
should be dropped and letters folded to a single case, so both the
string '
BasicLatin
' and the string '
-- basic
LATIN --
' will match the block name "Basic Latin".
The handling of block names in block escapes differs from this
behavior in two ways. First, the normalized block names defined in
this specification do not suppress hyphens in the Unicode block
names and do not level case distinctions. The normalized form of the
block name '
Latin-1 Supplement
', for example, is thus
Latin-1Supplement
', not
latin1supplement
' or
LATIN1SUPPLEMENT
'. Second, XSD processors are not
required to perform any normalization at all upon the block name as
given in the
block escape
, so
\p{Latin-1Supplement}
' will be recognized
as a reference to the Latin-1 Supplement block, but
\p{Is Latin-1 supplement}
' will not.
[Unicode Database]
has been revised since XSD 1.0 was
published, and is subject to future revision. In particular, the
grouping of code points into blocks has changed, and may change
again. All
minimally conforming
processors
must
support the blocks defined in the version of
[Unicode Database]
cited in the normative references (
Normative (§K.1)
) or in some
later version of the Unicode database.
Implementors
are encouraged to support the blocks defined in earlier and/or later
versions of the Unicode Standard. When the implementation supports
multiple versions of the Unicode database, and they differ in salient
respects (e.g. different characters are assigned to a given block in
different versions of the database), then it is
implementation-defined
which
set of block definitions is used for any given assessment episode.
In particular, the version of
[Unicode Database]
referenced in XSD 1.0 (namely, Unicode 3.1)
contained a number of
blocks which have been renamed in later versions of the
database Since the
older block names may appear in regular expressions within
XSD 1.0 schemas, implementors are encouraged to support the superseded
block names in XSD 1.1 processors for compatibility, either by default
or
at user option
. At the time this
document was prepared, block names from Unicode 3.1 known to have been
superseded in this way included:
#x0370 - #x03FF: Greek
#x20D0 - #x20FF: CombiningMarksforSymbols
#xE000 - #xF8FF: PrivateUse
#xF0000 - #xFFFFD: PrivateUse
#x100000 - #x10FFFD: PrivateUse
A tabulation of normalized block names for Unicode 2.0.0 and
later is given in
[Unicode block names]
For the treatment of regular expressions
containing unrecognized Unicode block names, see
Unrecognized category escapes (§G.4.2.4)
G.4.2.4 Unrecognized category escapes
A string of the form "
\p{
constitutes a
catEsc
(category escape), and similarly
a string of the form "
\P{
" constitutes
complEsc
(category-complement escape) only if the
string
matches either
IsCategory
or
IsBlock
Note:
If an unknown string of characters is used in a
category escape instead of a known character category code
or a string matching the
IsBlock
production,
the resulting string will (normally) not match the
regExp
production and thus not be a regular
expression as defined in this specification. If the
non-
regExp
string occurs where a regular
expression is required, the schema document will be in
error
Any string of hyphens, digits, and Basic Latin characters
beginning with '
Is
' will match the non-terminal
IsBlock
and thus be allowed in a regular expression.
Most of these strings, however, will not denote any Unicode block.
Processors
should
issue a warning if they encounter a regular
expression using a block name they do not recognize. Processors
may
at user option
treat unrecognized block names as
errors
in
the schema.
Note:
Treating unrecognized block names as errors increases the
likelihood that errors in spelling the block name will be detected
and can be helpful in checking the correctness of schema
documents. However, it also decreases the portability of schema
documents among processors supporting different versions of
[Unicode Database]
; it is for this reason that
processors are allowed to treat unrecognized block names as
errors only when the user has explicitly requested this
behavior.
If a string "
Is
" matches the
non-terminal
IsBlock
but
is not a recognized
block name, then the expressions
\p{Is
" and
\P{Is
" each denote the set of all
characters.
Processors
may
at user option
treat both
\p{Is
" and
\P{Is
" as
denoting the empty set, instead of the set of all characters.
Note:
The meaning defined for a block escape with an unrecognized
block name makes it synonymous with the regular expression
.|[\n\r]
'. A processor which does not recognize
the block name will thus not enforce the constraint that the
characters matched are in, or are not in, the block in question.
Any string which satisfies the regular expression as written will
be accepted, but not all strings accepted will actually satisfy
the expression as written: some strings which do not satisfy the
expression as written will also be accepted. So some invalid input
will be wrongly identified as valid.
If (at
user option
) the expressions are treated as denoting the
empty set, then the converse is true: any string which fails to
satisfy the expression as written will be rejected, but not all
strings rejected by the processor will actually have failed to satisfy
the expression as written. So some valid input will be wrongly
identified as invalid.
Which behavior is preferable in concrete circumstances depends on
the relative cost of failure to accept valid input (false negatives)
and failure to reject invalid input (false positives). It is for
this reason that processors are allowed to provide
user options
to
control the behavior. The principle of being liberal in accepting
input (often called Postel's Law) suggests that the default
behavior should be to accept strings not known to be invalid,
rather than the converse; it is for this reason that block escapes
with unknown block names should be treated as matching any character
unless the user explicitly requests the alternative behavior.
G.4.2.5 Multi-character escapes
[Definition:]
multi-character escape
provides a simple way to identify
any of
a commonly used set of characters:
[Definition:]
The
wildcard character
is a metacharacter which matches
almost any single character:
Multi-Character Escape
[97]
MultiCharEsc
::=
'\' [sSiIcCdDwW]
[98]
WildcardEsc
::=
'.'
Character sequence
Equivalent
character class
[^\n\r]
\s
[#x20\t\n\r]
\S
[^\s]
\i
the set of initial name characters, those
matched
by
NameStartChar
in
[XML]
\I
[^\i]
\c
the set of name characters, those
matched
by
NameChar
\C
[^\c]
\d
\p{Nd}
\D
[^\d]
\w
[#x0000-#x10FFFF]-[\p{P}\p{Z}\p{C}]
all characters except the set of "punctuation",
"separator" and "other" characters
\W
[^\w]
Note:
The
regular expression
language defined here does not
attempt to provide a general solution to "regular expressions" over
UCS character sequences. In particular, it does not easily provide
for matching sequences of base characters and combining marks.
The language is targeted at support of "Level 1" features as defined in
[Unicode Regular Expression Guidelines]
. It is hoped that future versions of this
specification will provide support for "Level 2" features.
H Implementation-defined and implementation-dependent features (normative)
H.1 Implementation-defined features
The following features in this specification are
implementation-defined
Any software which claims to conform to this specification (or to the
specification of any host language which embeds
XSD 1.1: Datatypes
must
describe how these choices
have been exercised, in documentation which accompanies any conformance claim.
For the datatypes which depend on
[XML]
or
[Namespaces in XML]
, it is
implementation-defined
whether a conforming processor takes the relevant
definitions from
[XML]
and
[Namespaces in XML]
, or
from
[XML 1.0]
and
[Namespaces in XML 1.0]
Implementations
may
support either
the form of these datatypes based on version 1.0 of those
specifications, or the form based on version 1.1, or both.
For the datatypes with infinite
value spaces
, it
is
implementation-defined
whether conforming processors
set a limit on the size of the values supported.
If such limits are set, they
must
be documented,
and the limits
must
be equal to, or exceed, the
minimal limits specified in
Partial Implementation of Infinite Datatypes (§5.4)
It is
implementation-defined
whether
primitive
datatypes other than
those defined in this specification are supported.
For each
implementation-defined
datatype, a
Simple Type Definition
must
be
specified which conforms to the rules given in
Built-in Simple Type Definitions (§4.1.6)
In addition, the following information
must
be provided:
The nature of the datatype's
lexical space
value space
and
lexical mapping
The nature of the equality relation; in particular, how to determine
whether two values which are not identical are equal.
Note:
There is no requirement that equality be distinct from identity,
but it
may
be.
The values of the
fundamental facets
Which of the
constraining facets
defined in this specification
are applicable to the datatype (and
may
thus be used in
facet-based restriction
from it), and what they mean when
applied to it.
If
implementation-defined
constraining facets
are supported, which of those
constraining facets
are applicable to the datatype, and what they
mean when applied to it.
What URI reference (more precisely, what
anyURI
value)
is to be used to refer to the datatype, analogous to those provided
for the datatypes defined here in section
Built-in Datatypes and Their Definitions (§3)
Note:
It is convenient if the URI for a datatype and the
expanded name
of its simple type definition are related by a
simple mapping, like the URIs given for the
built-in
datatypes
in
Built-in Datatypes and Their Definitions (§3)
. However, this is not
a requirement.
For each
constraining facet
given a value for the new
primitive
what URI reference (more precisely, what
anyURI
value)
is to be used to refer to the usage of that facet on the datatype,
analogous to those provided, for the
built-in
datatypes, in section
Built-in Datatypes and Their Definitions (§3)
Note:
As specified normatively elsewhere, the set of facets given values
will at the very least include the
whiteSpace
facet.
The
value space
of the
primitive
datatype
must
be disjoint
from those of the other
primitive
datatypes.
The
lexical mapping
defined for an
implementation-defined
primitive
must
be a total function from the
lexical space
onto the
value space
. That is, (1) each
literal
in the
lexical space
must
map to exactly one value, and (2) each value
must
be
the image of at least one member of the
lexical space
, and
may
be the image of more than one.
For consistency with the
constraining facets
defined here,
implementors who define new
primitive
datatypes
should
allow
the
pattern
and
enumeration
facets to apply.
The implementor
should
specify a
canonical mapping
for the datatype if practicable.
It is
implementation-defined
whether
constraining facets
other than
those defined in this specification are supported.
For each
implementation-defined
facet, the following information
must
be provided:
What properties the facet has, viewed as a schema component.
Note:
For most
implementation-defined
facets, the structural pattern used
for most
constraining facets
defined in this specification is
expected to be satisfactory, but other structures
may
be specified.
Whether the facet is a
pre-lexical
lexical
, or
value-based
facet.
Whether restriction of the facet takes the form of replacing
a less restrictive facet value with a more restrictive value
(as in the
minInclusive
and most other
constraining facets
defined in this specification) or
of adding new values to a set of facet values (as
for the
pattern
facet). In the former case,
the information provided
must
also specify how to determine
which of two given values is more restrictive (and thus can
be used to restrict the other).
When an
implementation-defined
facet is used in
facet-based restriction
, the
new value
must
be at least as restrictive as the existing
value, if any.
Note:
The effect of the preceding paragraph is to ensure that
a type derived by
facet-based restriction
using an
implementation-defined
facet does not allow, or appear to allow, values not present
in the
base type
What
primitive
datatypes the new
constraining facet
applies to, and what it
means when applied to them.
For a
pre-lexical
facet, how to compute the result
of applying the facet value to any given
literal
For a
pre-lexical
facet, the
order in which it is applied to
literals
, relative to
other
pre-lexical
facets.
For a
lexical
facet, how to tell whether any given
literal
is facet-valid with respect to it.
For a
value-based
facet, how to tell whether any
given value in the relevant
primitive
datatypes
is facet-valid with respect to it.
Note:
The host language
may
choose to specify that
implementation-defined
constraining facets
are applicable to
built-in
primitive
datatypes; this information is necessary to make the
implementation-defined
facet usable in such host languages.
What URI reference (more precisely, what
anyURI
value)
is to be used to refer to the facet, analogous to those provided
for the datatypes defined here in section
Built-in Datatypes and Their Definitions (§3)
What element is to be used in XSD schema documents to apply the facet
in the course of
facet-based restriction
. A schema document
must
be
provided with an element declaration for each
implementation-defined
facet;
the element declarations
should
specify
xs:facet
as
their substitution-group head.
Note:
The elements'
expanded names
are used by the condition-inclusion
mechanism of
[XSD 1.1 Part 1: Structures]
to allow schema authors to test whether
a particular facet is supported and adjust the schema document's
contents accordingly.
Implementation-defined
pre-lexical
facets
must not
, when
applied to
literals
which have been whitespace-normalized
by the
whiteSpace
facet, produce
literals
which are
no longer whitespace-normalized.
It is
implementation-defined
whether an implementation of this specification
supports other versions of the Unicode database
[Unicode Database]
in addition to the version cited normatively in the normative
references (
Normative (§K.1)
). If an implementation supports
additional versions of the Unicode database, it is
implementation-defined
which character properties and which block name definitions are
used in a given validity assessment.
It is
implementation-defined
whether an implementation is capable,
at user option
, of treating unrecognized block names as errors
in a schema.
It is
implementation-defined
whether an implementation is capable,
at user option
, of treating unrecognized category escapes as
denoting the empty set instead of the set of all characters.
Note:
It follows from the above that each
implementation-defined
primitive
datatype and each
implementation-defined
constraining facet has an
expanded name
These
expanded names
are used by the condition-inclusion mechanism
of
[XSD 1.1 Part 1: Structures]
to allow schema authors to test whether a
particular datatype or facet is supported and adjust the schema document's
contents accordingly.
H.2 Implementation-dependent features
The following features in this specification are
implementation-dependent
Software which claims to conform to this specification (or to the
specification of any host language which embeds
XSD 1.1: Datatypes
may
describe how these choices
have been exercised, in documentation which accompanies any conformance claim.
When multiple errors are encountered in type definitions or elsewhere,
it is
implementation-dependent
how many of the errors are reported (as long
as at least one error is reported), and which,
what form the report of errors takes, and how much detail is included.
I Changes since version 1.0
I.1 Datatypes and Facets
In order to align this specification with
those being prepared by the XSL and XML Query Working Groups, a new
datatype named
anyAtomicType
has been introduced; it
serves as the base type definition for all
primitive
atomic
datatypes.
The treatment of datatypes has been made more
precise and explicit; most of these changes affect the section on
Datatype System (§2)
. Definitions have been revised thoroughly and
technical terms are used more consistently.
The (numeric) equality of values is now distinguished from
the identity of the values themselves; this allows
float
and
double
to treat positive and negative
zero as distinct values, but nevertheless
to treat them as equal for purposes of bounds checking. This allows a
better alignment with the expectations of users working with IEEE
floating-point binary numbers.
The
{value}
of the
bounded
component for
list
datatypes is now always
false
, reflecting the fact that no ordering is prescribed for
list
datatypes, and so
they cannot be bounded using the facets defined by this
specification.
Units of length have been specified for all datatypes that are permitted
the length constraining facet.
The use of the namespace
has been
deprecated. The definition of a namespace separate from the main
namespace defined by this specification proved not to be necessary or
helpful in facilitating the use, by other specifications, of the
datatypes defined here, and its use raises a number of difficult
unsolved practical questions.
An
assertions
facet has been added, to allow schema
authors to associated assertions with simple type definitions,
analogous to those allowed by
[XSD 1.1 Part 1: Structures]
for complex type definitions.
The discussion of whitespace handling in
whiteSpace (§4.3.6)
makes clearer that when
the value is
collapse
literals
consisting
solely of whitespace characters are reduced to the
empty string; the earlier formulation has been misunderstood
by some implementors.
Conforming implementations
may
now support
primitive
datatypes
and facets in addition to those defined here.
I.2 Numerical Datatypes
As noted above, positive and negative zero,
float
and
double
are now treated as
distinct but arithmetically equal values.
The description of the lexical spaces of
unsignedLong
unsignedInt
unsignedShort
, and
unsignedByte
has been revised to agree with the
schema for schemas by allowing for the possibility of a
leading sign.
The
float
and
double
datatypes now follow IEEE 754 implementation
practice more closely; in particular, negative and positive zero are
now distinct values, although arithmetically equal. Conversely, NaN is identical but not arithmetically equal
to itself.
The character sequence '
+INF
' has been added to the
lexical spaces of
float
and
double
I.3 Date/time Datatypes
The treatment of
dateTime
and related
datatypes has been changed to provide a more explicit account of
the value space in terms of seven numeric properties. The most
important substantive change is that values now explicitly retain
information about the time zone offset indicated in the lexical form; this
allows better alignment with the treatment of such values in
[XQuery 1.0 and XPath 2.0 Functions and Operators]
At the suggestion of the
W3C OWL Working Group
, a
explicitTimezone
facet
has been added to allow date/time datatypes to be restricted by
requiring or forbidding an explicit time zone offset from UTC,
instead of making it optional. The
dateTimeStamp
datatype has been defined using this facet.
The
treatment of the date/time datatype includes a carefully revised
definition of order that ensures that for repeating datatypes (
time
gDay
, etc.), timezoned values will be
compared as though they are on the same "calendar
day" ("local" property values) so that in
any given timezone, the days start at the local midnight and end just
before local midnight. Days do not run from 00:00:00Z to
24:00:00Z in timezones other than Z.
The lexical representation
0000
' for years is recognized and maps to the year 1
BCE; '
-0001
' maps to 2 BCE, etc. This is a change from
version 1.0 of this specification, in order to align with established
practice (the so-called "astronomical year
numbering") and
[ISO 8601]
Algorithms for arithmetic involving
dateTime
and
duration
values have been provided, and corrections
made to the
timeOnTimeline
function.
The treatment of leap seconds is no longer
implementation-defined
the date/time types described here do not include leap-second values.
At the suggestion of the
W3C
Internationalization Core Working Group
, most references to
"time zone" have been replaced with references to
"time zone offset"; this
resolves issue
4642
Terminology: zone offset versus time zone
A number of syntactic and semantic errors in some of the regular
expressions given to describe the lexical spaces of the
primitive
datatypes (most notably the date/time datatypes) have been corrected.
The lexical mapping for times of the form '
24:00:00
' (with
or without a trailing decimal point and zeroes) has been specified
explicitly.
I.4 Other changes
Support has been added for
[XML]
version 1.1 and
[Namespaces in XML]
version 1.1. The
datatypes which depend on
[XML]
and
[Namespaces in XML]
may now be used with the definitions provided by the 1.1 versions
of those specifications, as well as with the definitions in the
1.0 versions. It is
implementation-defined
whether software conforming
to this specification supports the definitions given in version 1.0,
or in version 1.1, of
[XML]
and
[Namespaces in XML]
To reduce confusion and avert a widespread misunderstanding,
the normative references to various W3C specifications now state
explicitly that while the reference describes the particular edition
of a specification current at the time this specification is
published, conforming implementations of this specification
are not required to ignore later editions of the other
specification but instead
may
support later editions, thus
allowing users of this specification to benefit from corrections to other
specifications on which this one depends.
The reference
to the Unicode Database
[Unicode Database]
has been updated from version 4.1.0 to version 5.1.0,
at the suggestion of the
W3C
Internationalization Core Working Group
References to various other specifications have also been updated.
The account of the value space of
duration
has been changed to specify that values consist only
of two numbers (the number of months and the number of seconds) rather
than six (years, months, days, hours, minutes, seconds). This allows
clearly equivalent durations like P2Y and P24M to have the same
value.
Two new totally ordered restrictions of
duration
have been defined:
yearMonthDuration
, defined in
yearMonthDuration (§3.4.26)
, and
dayTimeDuration
, defined in
dayTimeDuration (§3.4.27)
This allows better alignment with the treatment of durations in
[XQuery 1.0 and XPath 2.0 Functions and Operators]
The XML representations of the
primitive
and
ordinary
built-in datatypes have been moved out of the schema document
for schema documents in
Schema for Schema Documents (Datatypes)
(normative) (§A)
and into a
different appendix (
Illustrative XML representations for the built-in simple type definitions (§C)
).
Numerous minor corrections have been made in response to comments
on earlier working drafts.
The treatment of topics handled both in this specification and in
[XSD 1.1 Part 1: Structures]
has been revised to align
the two specifications more closely.
Several references to other specifications have been updated to
refer to current versions of those specifications, including
[XML]
[Namespaces in XML]
[RFC 3986]
[RFC 3987]
, and
[RFC 3548]
Requirements for the datatype-validity of values of type
language
have been clarified.
Explicit definitions have been provided for the lexical and
canonical mappings
of most of the primitive datatypes.
Schema Component Constraint
enumeration facet value required for NOTATION (§3.3.19)
which restricts the use of
NOTATION
to validate
literals
without first enumerating a
set of values, has been clarified.
Some errors in the definition of regular-expression metacharacters
have been corrected.
The descriptions of the
pattern
and
enumeration
facets have been revised to make clearer how
values from different derivation steps are combined.
A warning against using the whitespace facet for tokenizing
natural-language data has been added on the request of the W3C
Internationalization Working Group.
In order to correct an error in
version 1 of this specification and of
[XSD 1.1 Part 1: Structures]
unions
are no longer forbidden to be members of other
unions
Descriptions of
union
types have also
been changed to reflect the fact that
unions
can be derived by
restricting other
unions
. The concepts of
transitive membership
(the members of all members, recursively) and
basic member
(those datatypes in the transitive
membership which are not
unions
) have been introduced and are used.
The requirements of conformance have been clarified in various
ways.
A distinction is now made between
implementation-defined
and
implementation-dependent
features, and a list of
such features is provided in
Implementation-defined and implementation-dependent features (normative) (§H)
Requirements imposed on host languages which
use or incorporate the datatypes defined by this specification are
defined.
The definitions of
must
must not
, and
error
have been changed to specify that processors
must
detect and
report errors in schemas and schema documents (although the quality
and level of detail in the error report is not constrained).
The lexical mapping of the
QName
datatype,
in particular its dependence on the namespace bindings in
scope at the place where the
literal
appears,
has been clarified.
The characterization of
lexical mappings
has been revised to say
more clearly when they are functions and when they are not, and when
(in the
special
datatypes) there are values in the
value space
not
mapped to by any members of the
lexical space
The nature of equality and identity of lists
has been clarified.
Enumerations, identity constraints, and value constraints now
treat both identical values
and equal values as being the same for purposes of validation.
This affects primitive datatypes in which identity and equality
are not the same. Positive and negative zero, for example,
are not treated as different for purposes of keys, keyrefs,
or uniqueness constraints, and an enumeration which includes
either zero will accept either zero.
The mutual relations of lists and unions have been clarified, in
particular the restrictions on what kinds of datatypes
may
appear as
the
item type
of a list or among the
member types
of a union.
Unions with no member types (and thus with empty
value space
and
lexical space
) are now explicitly allowed.
Cycles in the definitions of
unions
and in the
derivation of simple types are now explicitly forbidden.
A number of minor errors and obscurities have been fixed.
J Glossary (non-normative)
The listing below is for the benefit of readers of a printed version of this
document: it collects together all the definitions which appear in the
document above.
Constraint on Schemas
Constraints on the schema components themselves, i.e. conditions
components
must
satisfy to be components at all.
Largely to be found in
Datatype components (§4)
Schema Representation Constraint
Constraints on the representation of schema components in XML.
Some but not all of these are expressed in
Schema for Schema Documents (Datatypes)
(normative) (§A)
and
DTD for Datatype Definitions (non-normative) (§B)
UTC
Universal
Coordinated Time
UTC
is an adaptation of TAI which closely approximates UT1 by adding
leap-seconds
to selected
UTC
days.
Validation Rule
Constraints expressed by schema components which information items
must
satisfy to be schema-valid. Largely to
be found in
Datatype components (§4)
XDM representation
For
any value
and any datatype
, the
XDM representation of
under
is
defined recursively as follows. Call the XDM representation
. Then
If
xs:anySimpleType
or
xs:anyAtomicType
then
is
and the
dynamic
type
of
is
xs:untypedAtomic
If
{variety}
atomic
then
let
T2
be the
nearest built-in datatype
to
If
is a member of the
value space
of
T2
, then
is
and the
dynamic type
of
is
T2
Otherwise (i.e. if
is not a member of the
value space
of
T2
),
is the
XDM representation
of
under
T2
{base type definition}
If
{variety}
list
then
is a sequence of atomic values, each atomic value
being the
XDM representation
of the corresponding
item in the list
under
{item type definition}
If
{variety}
union
then
is the
XDM representation
of
under the
active basic member
of
when validated against
If there is no
active basic member
then
has no
XDM representation
under
absent
Throughout this
specification, the value
absent
is used
as a distinguished value to indicate that a given instance of a property
"has no value" or "is absent".
active basic member
If the
active member type
is
itself a
union
, one of
its
members will be
its
active member type
, and so on, until
finally a
basic (non-union)
member
is reached. That
basic member
is
the
active basic member
of the union.
active member type
In a valid
instance of any
union
, the first of its members in order which
accepts the instance as valid is the
active member
type
ancestor
The
ancestors
of a
type definition
are its
{base type definition}
and the
ancestors
of its
{base type definition}
anyAtomicType
anyAtomicType
is a special
restriction
of
anySimpleType
The
value
and
lexical spaces
of
anyAtomicType
are the unions of the
value
and
lexical spaces
of all the
primitive
datatypes, and
anyAtomicType
is their
base type
anySimpleType
The definition of
anySimpleType
is a special
restriction
of
anyType
The
lexical space
of
anySimpleType
is the set of all sequences of Unicode
characters,
and its
value space
includes all
atomic values
and all finite-length lists of
zero or more
atomic values
atomic
Atomic
datatypes
are those whose
value spaces
contain only
atomic values
Atomic
datatypes are
anyAtomicType
and all
datatypes
derived
from it.
atomic value
An
atomic value
is an elementary value, not
constructed from simpler values by any user-accessible
means defined by this specification.
base type
Every datatype
other than
anySimpleType
is associated with another datatype, its
base type
Base types
can be
special
primitive
, or
ordinary
basic member
Those members of the
transitive membership
of a
union
datatype
which are themselves not
union
datatypes
are the
basic members
of
built-in
Built-in
datatypes are those which are defined in this
specification; they can
be
special
primitive
, or
ordinary
datatypes
canonical mapping
The
canonical mapping
is a prescribed subset of the inverse of a
lexical mapping
which is
one-to-one and whose domain (where possible) is the entire range of the
lexical mapping
(the
value space
).
canonical representation
The
canonical
representation
of a value in the
value space
of a datatype is
the
lexical representation
associated with that value by the
datatype's
canonical mapping
character class subtraction
character group
that contains a subtraction operator
is referred to as a
character class subtraction
character group part
character group part
charGroupPart
) is
any
of:
a single unescaped character
SingleCharNoEsc
),
a single escaped character
SingleCharEsc
),
a character class escape
charClassEsc
),
or a character range
charRange
).
constraining facet
Constraining facets
are schema components whose values may be set or changed
during
derivation
(subject to facet-specific controls)
to control various aspects of the derived datatype.
constructed
All
ordinary
datatypes are defined in terms of, or
constructed
from, other datatypes, either by
restricting
the
value space
or
lexical space
of a
base type
using zero or more
constraining facets
or by specifying the new datatype as a
list
of items of some
item type
or by defining it as a
union
of some specified
sequence of
member types
datatype
In
this specification, a
datatype
has
three properties:
value space
, which is a set of
values.
lexical space
, which is a set of
literals
used to denote the values.
A small collection of
functions, relations, and
procedures
associated with the datatype. Included are
equality and (for some datatypes)
order relations on the
value space
, and a
lexical mapping
, which is a mapping from the
lexical space
into
the
value space
derived
A datatype
is
immediately derived
from another datatype
if and only if
is the
base type
of
derived
A datatype
is
derived
from another
datatype
if and only if one of the following is true:
is the
base type
of
There is some datatype
such that
is the
base type
of
, and
is derived from
div
If
and
are numbers, then
div
is the greatest integer
less than or equal to
error
A failure of a
schema or schema
document
to conform to the rules of this specification.
Except as otherwise specified,
processors
must
distinguish
error-free (conforming) schemas and schema documents
from those with errors;
if a schema
used in type-validation or a schema document
used in constructing a schema
is in error, processors
must
report the fact;
if more than one is in error, it is
implementation-dependent
whether more than one is reported as being in error.
If more than one of the constraints given in
this specification is violated, it
is
implementation-dependent
how many of the violations, and which, are
reported.
Note:
Failure of an XML element or attribute to be
datatype-valid against a particular
datatype in a particular schema is not in itself a failure
to conform to this specification and thus,
for purposes of this specification, not an error.
facet-based restriction
datatype is defined by
facet-based restriction
of another datatype
(its
base type
),
when values for zero or more
constraining facets
are specified
that serve to constrain its
value space
and/or its
lexical space
to a subset of those of the
base type
for compatibility
A feature of this specification included solely to ensure that
schemas which use this feature remain compatible with
[XML]
fundamental facet
Each
fundamental facet
is a
schema component that provides a limited piece of information about
some aspect of each datatype.
implementation-defined
Something
which
may
vary among conforming implementations, but which
must
be specified by the implementor for each particular implementation,
is
implementation-defined
implementation-dependent
Something
which
may
vary among conforming implementations, is not specified by
this or any W3C specification, and is not required to be specified
by the implementor for any particular implementation,
is
implementation-dependent
incomparable
Two
values that are neither equal, less-than, nor greater-than are
incomparable
. Two values
that are not
incomparable
are
comparable
intervening union
If a datatype
is in the
transitive membership
of a
union
datatype
, but not one of
's
member types
then a sequence of one or more
union
datatypes necessarily exists,
such that the first is one of the
member types
of
, each
is one of the
member types
of its predecessor in the sequence, and
is one of the
member types
of the last in the sequence.
The
union
datatypes in this sequence are said to
intervene
between
and
. When
and
are given by the context, the datatypes
in the sequence are referred to as the
intervening unions
When
is one of the
member types
of
the set of
intervening unions
is the empty set.
item type
The
atomic
or
union
datatype that participates in the definition of a
list
datatype
is the
item type
of that
list
datatype.
leap-second
leap-second
is an additional second added
to the last day of December, June, October, or March,
when such an adjustment is deemed necessary by the
International Earth Rotation and Reference Systems Service
in order to keep
UTC
within 0.9 seconds
of observed astronomical time. When leap seconds are
introduced, the last minute in the day has more than
sixty seconds.
In theory leap seconds can also be removed from a
day, but this has not yet occurred.
(See
[International Earth Rotation Service (IERS)]
[ITU-R TF.460-6]
.)
Leap seconds are
not
supported by the types defined
here.
lexical
A constraining facet which
directly restricts the
lexical space
of a datatype
is a
lexical
facet.
lexical mapping
The
lexical mapping
for a datatype is a prescribed
relation
which maps from the
lexical space
of the datatype
into its
value space
lexical representation
The members of the
lexical space
are
lexical representations
of the values to which they are
mapped.
lexical space
The
lexical space
of a datatype is
the prescribed set of strings
which
the lexical
mapping
for that datatype
maps to values of that datatype.
list
List
datatypes are
those having values each of which consists of a finite-length
(possibly empty) sequence of
atomic values
. The values in a list are
drawn from some
atomic
datatype (or from
union
of
atomic
datatypes), which is
the
item type
of the
list
literal
A sequence of zero or more
characters in the Universal Character Set (UCS) which may or may not
prove upon inspection to be a member of the
lexical space
of a given
datatype and thus a
lexical representation
of a given value in that datatype's
value space
, is referred to as a
literal
match
(Of strings or names:)
Two strings or names being compared must be
identical. Characters with multiple possible representations in
ISO/IEC 10646 (e.g. characters with both precomposed and
base+diacritic forms) match only if they have the same representation
in both strings. No case folding is performed.
(Of strings and rules
in the grammar:)
A string matches a grammatical production
if and only if it belongs to the language
generated by that production.
may
Schemas,
schema documents, and processors
are permitted to but need
not behave as described.
member types
The datatypes that participate in the
definition of a
union
datatype are known as the
member types
of that
union
datatype.
minimally conforming
Implementations claiming
minimal conformance
to this specification
independent of any host language
must
do
all
of the following:
Support all the
built-in
datatypes defined in this specification.
Completely and correctly implement all of
the
constraints on schemas
defined in this specification.
Completely and correctly implement all of
the
Validation Rules
defined in this specification, when checking the
datatype validity of literals against datatypes.
mod
If
and
are numbers, then
mod
is
× (
div
) .
must
(Of schemas and
schema documents:)
Schemas and documents
are required to behave as described; otherwise they are in
error
(Of processors:)
Processors are required to behave as described.
must not
Schemas, schema documents
and processors are forbidden to behave as
described; schemas and documents which nevertheless
do so are in
error
nearest built-in datatype
For
any datatype
, the
nearest built-in datatype
to
is the first
built-in
datatype encountered in following
the chain of links connecting each datatype to its
base type
. If
is a
built-in
datatype, then the
nearest built-in datatype of
is
itself; otherwise,
it is the nearest built-in datatype of
's
base type
normalized block name
For any Unicode block, the
normalized block name
of that
block is the string of characters formed by stripping out white space
and underbar characters from the block name as given in
[Unicode Database]
, while retaining hyphens and preserving case
distinctions.
optional
An
optional
property is
permitted
but not
required
to have
the distinguished
value
absent
ordered
value space
, and hence a datatype, is said to be
ordered
if some
members of the
value space
are
drawn from a
primitive
datatype for which
the table in
Fundamental Facets (§F.1)
specifies
the value
total
or
partial
for
the
ordered
facet.
ordinary
Ordinary
datatypes are all datatypes other than the
special
and
primitive
datatypes.
owner
component may be referred to as the
owner
of its properties, and of the values of
those properties.
pre-lexical
A constraining facet which
is used to normalize an initial
literal
before checking
to see whether the resulting character sequence is a member of a datatype's
lexical space
is a
pre-lexical
facet.
primitive
Primitive
datatypes are those
datatypes that are not
special
and are
not defined in terms of other datatypes;
they exist
ab initio
regular expression
regular expression
is composed from zero or more
branches
separated by
characters.
restriction
A datatype
is a
restriction
of another
datatype
when
should
It is recommended that schemas, schema documents, and
processors behave as described, but there
can be valid reasons for them not to; it is important that the
full implications be understood and carefully weighed before
adopting behavior at variance with the recommendation.
special
The
special
datatypes are
anySimpleType
and
anyAtomicType
special value
special value
is
an object
whose only relevant properties for purposes of this specification are that it
is distinct from, and unequal to, any other values (special or otherwise).
transitive membership
The
transitive membership
of
union
is the set of its own
member types
, and the
member types
of its members, and so on. More formally, if
is a
union
, then (a) its
member types
are in the transitive membership
of
, and (b) for any datatypes
T1
and
T2
, if
T1
is in the transitive membership of
and
T2
is one of the
member types
of
T1
, then
T2
is also in the transitive membership
of
union
Union
datatypes
are (a) those whose
value spaces
lexical spaces
, and
lexical mappings
are the union of the
value spaces
lexical spaces
, and
lexical mappings
of one or more other datatypes, which are the
member types
of the
union, or (b) those derived by
facet-based restriction
of another union datatype.
unknown
datatype which is not available for use is said to be
unknown
unknown
An
constraining facet
which is not supported by
the processor in use is
unknown
user option
A choice left under the control of the user of a processor,
rather than being fixed for all users or uses of the processor.
Statements in this specification that "Processors
may
at user option" behave in a certain way mean that
processors
may
provide mechanisms to allow users
(i.e. invokers of the processor) to enable or disable the
behavior indicated. Processors which do not provide such
user-operable controls
must not
behave in the way indicated.
Processors which do provide such
user-operable controls
must
make it possible for the user
to disable the optional behavior.
Note:
The normal expectation is that the default setting for
such options will be to disable the
optional
behavior in question,
enabling it only when the user explicitly requests it. This
is not, however, a requirement of conformance: if the
processor's documentation makes clear that the user can
disable the optional
behavior, then invoking the processor without
requesting that it be disabled can be taken as equivalent to
a request that it be enabled.
It is required,
however, that it in fact be possible for the user to disable the
optional behavior.
Note:
Nothing in this specification constrains the manner
in which processors allow users to control user options.
Command-line options, menu choices in a graphical user
interface, environment variables, alternative call patterns
in an application programming interface, and other
mechanisms may all be taken as providing user options.
user-defined
User-defined
datatypes are those
datatypes that are defined by individual schema designers.
value space
The
value space
of a
datatype
is the set of values for that
datatype.
value-based
A constraining facet which
directly restricts the
value space
of a datatype
is a
value-based
facet.
wildcard character
The
wildcard character
is a metacharacter which matches
almost any single character:
K References
K.1 Normative
IEEE 754-2008
IEEE.
IEEE Standard for Floating-Point Arithmetic
. 29
August 2008.
Namespaces in XML
World Wide Web Consortium.
Namespaces in XML 1.1
(Second Edition)
ed. Tim Bray et al.
W3C Recommendation
16 August 2006.
Available at:
The edition cited is the one current at the date of publication of this
specification. Implementations
may
follow the edition cited and/or
any later edition(s); it is implementation-defined which.
For details of the dependency of this specification
on Namespaces in XML 1.1, see
Dependencies on Other Specifications (§1.3)
Namespaces in XML 1.0
World Wide Web Consortium.
Namespaces in XML 1.0 (Third Edition)
ed. Tim Bray et al.
W3C Recommendation
8 December 2009.
Available at:
The edition cited is the one current at the date of publication of this
specification. Implementations
may
follow the edition cited and/or
any later edition(s); it is implementation-defined which.
For details of the
dependency of this specification
on Namespaces in XML 1.0, see
Dependencies on Other Specifications (§1.3)
RFC 3548
S. Josefsson, ed.
RFC 3548: The Base16, Base32, and Base64 Data Encodings
July 2003. Available at:
Unicode Database
The Unicode Consortium.
Unicode Character Database
Revision 3.1.0, ed. Mark Davis and Ken Whistler.
2001-02-28.
Available at:
For later versions, see
The edition cited is the one current at the date of publication of XSD 1.0.
Implementations
may
follow the edition cited and/or
any later edition(s); it is implementation-defined which.
XDM
World Wide Web Consortium.
XQuery 1.0 and XPath 2.0 Data Model
(XDM) (Second Edition)
ed. Mary Fernández et al.
W3C Recommendation
14 December 2010.
Available at:
XML
World Wide Web Consortium.
Extensible Markup Language (XML) 1.1
(Second Edition)
ed.
Tim Bray et al.
W3C Recommendation 16 August 2006, edited in place 29 September 2006.
Available at
The edition cited is the one current at the date of publication of this
specification. Implementations
may
follow the edition cited and/or
any later edition(s); it is implementation-defined which.
For details of the dependency of this specification
on XML 1.1, see
Dependencies on Other Specifications (§1.3)
XML 1.0
World Wide Web Consortium.
Extensible Markup Language (XML) 1.0 (Fifth Edition)
, ed.
Tim Bray et al.
W3C Recommendation 26 November 2008.
Available at
The edition cited is the one current at the date of publication of this
specification. Implementations
may
follow the edition cited and/or
any later edition(s); it is implementation-defined which.
For details of the
dependency of this specification
on XML, see
Dependencies on Other Specifications (§1.3)
XPath 2.0
World Wide Web Consortium.
XML Path Language (XPath)
2.0 (Second Edition)
ed. Anders Berglund et al.
W3C Recommendation
14 December 2010
(Link errors corrected 3 January 2011)
Available at:
XQuery 1.0 and XPath 2.0 Functions and Operators
World Wide Web Consortium.
XQuery 1.0 and XPath 2.0 Functions and Operators
(Second Edition)
ed. Ashok Malhotra et al.
W3C Recommendation
14 December 2010.
Available at:
XSD 1.1 Part 1: Structures
World Wide Web Consortium.
W3C XML Schema Definition Language (XSD) 1.1 Part 1:
Structures
, ed. Shudi (Sandy) Gao 高殊镝,
C. M. Sperberg-McQueen,
and Henry S. Thompson.
W3C Recommendation 5 April 2012.
Available at:
The edition cited is the one current at the date of publication of this
specification. Implementations
may
follow the edition cited and/or
any later edition(s); it is implementation-defined which.
K.2 Non-normative
BCP 47
Internet Engineering Task Force (IETF).
Best Current Practices 47.
2006. Available at:
Concatenation of
RFC 4646: Tags for Identifying Languages
ed. A. Phillips and M. Davis, September 2006,
and
RFC 4647: Matching of Language Tags
ed. A Phillips and M. Davis, September 2006,
Clinger, WD (1990)
William D Clinger.
How to Read Floating Point Numbers Accurately.
In
Proceedings of Conference on Programming Language Design and
Implementation
, pages 92-101.
Available at:
ftp://ftp.ccs.neu.edu/pub/people/will/howtoread.ps
HTML 4.01
World Wide Web Consortium.
HTML 4.01
Specification
, ed. Dave Raggett,
Arnaud Le Hors,
and
Ian Jacobs.
W3C Recommendation 24 December 1999.
Available at:
ISO 11404
ISO (International Organization for Standardization).
Language-independent Datatypes.
ISO/IEC 11404:2007.
See
ISO 8601
ISO (International Organization for Standardization).
Representations of dates and times, 1988-06-15.
ISO 8601:2000 Second Edition
ISO (International Organization for Standardization).
Representations of dates and times, second edition, 2000-12-15.
ITU-R TF.460-6
International
Telecommunication Union (ITU).
Recommendation ITU-R TF.460-6: Standard-frequency
and time-signal emissions
[Geneva: ITU, February 2002.]
International Earth Rotation Service (IERS)
International Earth Rotation Service (IERS).
See
LEIRI
Legacy extended IRIs for XML resource identification
ed. Henry S. Thompson, Richard Tobin, and Norman Walsh.
W3C Working Group Note 3 November 2008
(BNF comment style corrected in place 2009-07-09).
See
Perl
The Perl Programming Language. See
Precision Decimal
World Wide Web Consortium.
An XSD datatype for IEEE floating-point decimal
ed. David Peterson and C. M. Sperberg-McQueen.
W3C Working Group Note 9 June 2011.
Available at
RDF Schema
World Wide Web Consortium.
RDF Vocabulary Description Language 1.0: RDF Schema
ed. Dan Brickley and R. V. Guha.
W3C Recommendation 10 February 2004.
Available at:
RFC 2045
N. Freed and N. Borenstein.
RFC 2045: Multipurpose Internet Mail Extensions
(MIME) Part One: Format of Internet Message Bodies
. 1996. Available at:
RFC 3066
H. Alvestrand, ed.
RFC 3066: Tags for the Identification of Languages
1995. Available at:
RFC 3986
T. Berners-Lee,
R. Fielding, and L. Masinter,
RFC 3986: Uniform Resource Identifier (URI): Generic
Syntax
. January 2005. Available at:
RFC 3987
M. Duerst and M. Suignard.
RFC 3987: Internationalized Resource Identifiers (IRIs)
. January 2005. Available at:
RFC 4646
A. Phillips and M. Davis, ed.
RFC 4646: Tags for Identifying Languages
2006. Available at:
RFC 4647
A. Phillips and M. Davis, ed.
RFC 4647: Matching of Language Tags
2006. Available at:
Ruby
World Wide Web Consortium.
Ruby Annotation
ed. Marcin Sawicki et al.
W3C Recommendation 31 May 2001
(Markup errors corrected 25 June 2008).
Available at:
SQL
ISO (International Organization for Standardization).
ISO/IEC
9075-2:1999, Information technology --- Database languages ---
SQL --- Part 2: Foundation (SQL/Foundation)
[Geneva]: International Organization for Standardization, 1999.
See
Timezones
World Wide Web Consortium.
Working with Time Zones
ed. Addison Phillips et al.
W3C Working Group Note 5 July 2011.
Available at
U.S. Naval Observatory Time Service Department
Information about Leap Seconds
Available at:
USNO Historical List
U.S. Naval Observatory Time Service Department,
Historical list of leap seconds
Available at:
ftp://maia.usno.navy.mil/ser7/tai-utc.dat
Unicode Regular Expression Guidelines
Mark Davis.
Unicode Regular Expression Guidelines
, 1988.
Available at:
Unicode block names
World Wide Web Consortium.
Unicode block names for use in XSD regular expressions
ed. C. M. Sperberg-McQueen.
W3C Working Group Note 9 June 2011.
Available at:
XML Schema Language: Part 0 Primer
World Wide Web Consortium.
XML Schema Language: Part 0 Primer
Second Edition,
ed. David C. Fallside and Priscilla Walmsley.
W3C Recommendation 28 October 2004.
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XML Schema Requirements
XML Schema Requirements
ed.
Ashok Malhotra and Murray Maloney.
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Note 15 February 1999.
Available at:
XSL
World Wide Web Consortium.
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ed. Anders Berglund.
W3C Recommendation 05 December 2006.
Available at:
L Acknowledgements (non-normative)
Along with the
editors thereof, the following
contributed material to the first
version
of this specification:
Asir S. Vedamuthu, webMethods, Inc
Mark Davis, IBM
Co-editor Ashok Malhotra's work on this specification from March 1999 until
February 2001 was supported by IBM, and from then
until May 2004 by Microsoft. Since July 2004 his work
on this specification has been supported by Oracle Corporation.
The work of Dave Peterson
as a co-editor of this specification was supported by IDEAlliance
(formerly GCA) through March 2004, and beginning in
April 2004 by SGML
Works!
The work of C. M. Sperberg-McQueen
as a co-editor of this specification was supported by the World
Wide Web Consortium through January 2009 and again from June 2010
through May 2011, and beginning in
February 2009 by Black Mesa Technologies LLC.
The XML Schema Working Group acknowledges with thanks the members
of other W3C Working Groups and industry experts in other
forums who have contributed directly or indirectly to the creation
of this document and its predecessor.
At the time this document is published, the members
in good standing of the XML Schema Working Group are:
David Ezell, National Association of Convenience Stores (NACS) (
chair
Shudi (Sandy) Gao 高殊镝, IBM
Mary Holstege, Mark Logic
Sam Idicula, Oracle Corporation
Michael Kay, Invited expert
Jim Melton, Oracle Corporation
Dave Peterson, Invited expert
Liam Quin, W3C (
staff contact
C. M. Sperberg-McQueen, invited expert
Henry S. Thompson, University of Edinburgh
Kongyi Zhou, Oracle Corporation
The XML Schema Working Group has benefited in its work from the
participation and contributions of a number of people who are no
longer members of the Working Group in good standing at the time
of publication of this Working Draft. Their names are given below.
In particular we note
with sadness the accidental death of Mario Jeckle shortly before
publication of the first Working Draft of XML Schema 1.1.
Affiliations given are (among) those current at the time of the
individuals' work with the WG.
Paula Angerstein, Vignette Corporation
Leonid Arbouzov, Sun Microsystems
Jim Barnette, Defense Information Systems Agency (DISA)
David Beech, Oracle Corp.
Gabe Beged-Dov, Rogue Wave Software
Laila Benhlima, Ecole Mohammadia d'Ingenieurs Rabat (EMI)
Doris Bernardini, Defense Information Systems Agency (DISA)
Paul V. Biron, HL7; later Invited expert
Don Box, DevelopMentor
Allen Brown, Microsoft
Lee Buck, TIBCO Extensibility
Greg Bumgardner, Rogue Wave Software
Dean Burson, Lotus Development Corporation
Charles E. Campbell, Invited expert
Oriol Carbo, University of Edinburgh
Wayne Carr, Intel
Peter Chen, Bootstrap Alliance and LSU
Tyng-Ruey Chuang, Academia Sinica
Tony Cincotta, NIST
David Cleary, Progress Software
Mike Cokus, MITRE
Dan Connolly, W3C (
staff contact
Ugo Corda, Xerox
Roger L. Costello, MITRE
Joey Coyle, Health Level Seven
Haavard Danielson, Progress Software
Josef Dietl, Mozquito Technologies
Kenneth Dolson, Defense Information Systems Agency (DISA)
Andrew Eisenberg, Progress Software
Rob Ellman, Calico Commerce
Tim Ewald, Developmentor
Alexander Falk, Altova GmbH
David Fallside, IBM
George Feinberg, Object Design
Dan Fox, Defense Logistics Information Service (DLIS)
Charles Frankston, Microsoft
Matthew Fuchs, Commerce One
Andrew Goodchild, Distributed Systems Technology Centre (DSTC Pty Ltd)
Xan Gregg, TIBCO Extensibility
Paul Grosso, Arbortext, Inc
Martin Gudgin, DevelopMentor
Ernesto Guerrieri, Inso
Dave Hollander, Hewlett-Packard Company (
co-chair
Nelson Hung, Corel
Jane Hunter, Distributed Systems Technology Centre (DSTC Pty Ltd)
Michael Hyman, Microsoft
Renato Iannella, Distributed Systems Technology Centre (DSTC Pty Ltd)
Mario Jeckle, DaimlerChrysler
Rick Jelliffe, Academia Sinica
Marcel Jemio, Data Interchange Standards Association
Simon Johnston, Rational Software
Kohsuke Kawaguchi, Sun Microsystems
Dianne Kennedy, Graphic Communications Association
Janet Koenig, Sun Microsystems
Setrag Khoshafian, Technology Deployment International (TDI)
Melanie Kudela, Uniform Code Council
Ara Kullukian, Technology Deployment International (TDI)
Andrew Layman, Microsoft
Dmitry Lenkov, Hewlett-Packard Company
Bob Lojek, Mozquito Technologies
John McCarthy, Lawrence Berkeley National Laboratory
Matthew MacKenzie, XML Global
Nan Ma, China Electronics Standardization Institute
Eve Maler, Sun Microsystems
Ashok Malhotra, IBM, Microsoft, Oracle
Murray Maloney, Muzmo Communication, acting for Commerce One
Paolo Marinelli, University of Bologna
Lisa Martin, IBM
Noah Mendelsohn, Lotus; IBM; invited expert
Adrian Michel, Commerce One
Alex Milowski, Invited expert
Don Mullen, TIBCO Extensibility
Murata Makoto, Xerox
Ravi Murthy, Oracle
Chris Olds, Wall Data
Frank Olken, Lawrence Berkeley National Laboratory
David Orchard, BEA Systems, Inc.
Paul Pedersen, Mark Logic Corporation
Shriram Revankar, Xerox
Mark Reinhold, Sun Microsystems
Jonathan Robie, Software AG
Cliff Schmidt, Microsoft
John C. Schneider, MITRE
Eric Sedlar, Oracle Corp.
Lew Shannon, NCR
Anli Shundi, TIBCO Extensibility
William Shea, Merrill Lynch
Jerry L. Smith, Defense Information Systems Agency (DISA)
John Stanton, Defense Information Systems Agency (DISA)
Tony Stewart, Rivcom
Bob Streich, Calico Commerce
William K. Stumbo, Xerox
Hoylen Sue, Distributed Systems Technology Centre (DSTC Pty Ltd)
Ralph Swick, W3C
John Tebbutt, NIST
Ross Thompson, Contivo
Matt Timmermans, Microstar
Jim Trezzo, Oracle Corp.
Steph Tryphonas, Microstar
Scott Tsao, The Boeing Company
Mark Tucker, Health Level Seven
Asir S. Vedamuthu, webMethods, Inc
Fabio Vitali, University of Bologna
Scott Vorthmann, TIBCO Extensibility
Priscilla Walmsley, XMLSolutions
Norm Walsh, Sun Microsystems
Cherry Washington, Defense Information Systems Agency (DISA)
Aki Yoshida, SAP AG
Stefano Zacchiroli, University of Bologna
Mohamed Zergaoui, Innovimax