Each built-in datatype in this specification can be uniquely addressed via a
URI Reference constructed as follows:
Additionally, each facet definition element can be uniquely
addressed via a URI constructed as follows:
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:
- http://www.w3.org/2001/XMLSchema
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:
- http://www.w3.org/2001/XMLSchema-datatypes
This applies to all ·built-in· datatypes,
whether ·special·,
·primitive·, or
·ordinary·.
Each ·user-defined· datatype is also associated with a
unique namespace. However, ·user-defined· datatypes
do not come from the namespace defined by this specification; rather,
they come from the namespace of the schema in which they are defined
(see XML Representation of
Schemas in [XML Schema Part 1: Structures]).
3.3 Primitive Datatypes
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 facet·s which apply
to the datatype are listed;
and any datatypes
·constructed·
from this datatype are specified.
·Primitive·
datatypes can only be added by revisions
to this specification.
3.3.1 string
[Definition:] The string datatype
represents character strings in XML.
3.3.1.1 Value Space
The ·value space·
of string is the set of finite-length sequences of
characters (as defined in
[XML]) that ·match· the
Char production from [XML].
A 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.
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.
3.3.1.3
Facets
string has the following ·constraining facets·:
string has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from string may also
specify values for the
following·constraining facets·:
string has the
following values for its ·fundamental facets·:
- ordered = false
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.2 boolean
[Definition:] boolean
represents the
values of two-valued logic.
3.3.2.3
Facets
boolean has the following ·constraining facets·:
boolean 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:
Datatypes derived by
restriction from boolean may also
specify values for the
following·constraining facets·:
boolean has the
following values for its ·fundamental facets·:
- ordered = false
- bounded = false
- cardinality = finite
- numeric = false
3.3.3 decimal
Issue (RQ-150i):RQ-150 (minimum number of digits for decimal)The minimum number of digits implementations are required to support
will be lowered to 16 digits; a health warning will be added to note
that implementations of derived datatypes may support more digits of
precision than the base decimal type does, but that they are not required
to do so.
[Definition:] decimal
represents
a
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
i / 10n
where i and n are integers
and
n ≥ 0.
Precision is not reflected in this value space;
the number 2.0 is not distinct from the number 2.00.
(The datatype precisionDecimal may be used
for values in which precision is significant.)
The order relation on decimal
is the order relation on real numbers, restricted
to this subset.
3.3.3.1 Lexical
Mapping
decimal
has a lexical representation
consisting of a 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 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 mapping from values to canonical representations
is given formally in
·decimalCanonicalMap·.
3.3.3.2 Canonical representation
The canonical representation for decimal is defined by
prohibiting certain options from the
Lexical
Mapping (§3.3.3.1).
Specifically, the preceding optional
"+"
sign is prohibited. The decimal point is required. 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·.
3.3.3.3
Facets
decimal has the following ·constraining facets·:
decimal 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:
Datatypes derived by
restriction from decimal may also
specify values for the
following·constraining facets·:
decimal has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = false
- cardinality = countably infinite
- numeric = true
3.3.3.4 Datatypes based on decimal
The following ·built-in·
datatypes are
·derived·
from
decimal:
3.3.4 precisionDecimal
[Definition:] The precisionDecimal
datatype represents the
numeric value and (arithmetic) precision of decimal numbers which retain
precision; it also
includes special values for positive and negative infinity and
"not a number", and it differentiates
between "positive zero" and "negative
zero". The special values are
introduced to make the datatype correspond closely to
the
floating-point decimal datatypes described by the forthcoming
revision of IEEE/ANSI 754.
Precision is sometimes given in absolute, sometimes in relative
terms. [Definition:] The arithmetic precision of a value is
expressed in absolute quantitative terms,
by indicating
how many digits to the right of the decimal point are significant.
"5" has an arithmetic precision of 0, and
"5.01" an arithmetic precision of 2.
All ·minimally conforming· processors
must support all precisionDecimal values
in the ·value space· of the
otherwise unconstrained
·derived· datatype for which
totalDigits is set to sixteen, maxScale to 369,
and minScale to −398.
Note: Note: The conformance limits given in the text correspond to those
of the decimal64 type defined in the current draft of IEEE 754R, which
can be stored in a 64-bit field. The XML Schema Working Group
recommends that implementors support limits corresponding to those of
the decimal128 type. This entails supporting the values in the value
space of the otherwise unconstrained datatype for which
totalDigits is set to 34,
maxScale to 6176,
and
minScale to −6111.
Note: The XML Schema Working Group requests feedback from implementors
and users of XML Schema concerning the minimum and recommended
implementation limits for
precisionDecimal. If other
limits, larger or smaller, would make this dataytpe more attractive to
users or implementors, please let us know.
3.3.4.1 Value Space
a decimal number, positiveInfinity,
negativeInfinity or notANumber
Note: As explained below, the lexical
representation of the
precisionDecimal value object whose
·numericalValue·
is
notANumber is '
NaN'. Accordingly, in English text we
use 'NaN' to refer to that value. Similarly we use 'INF'
and '−INF' to refer to the two value objects whose
·numericalValue·
is
positiveInfinity and
negativeInfinity. These three value objects
are also informally called "not-a-number", "positive infinity",
and "negative infinity".
The latter two together are called
"the infinities".
Equality and order for precisionDecimal are defined as follows:
- Two numerical precisionDecimal values
are ordered (or equal) as their
·numericalValue· values are ordered (or equal).
(This means
that
two zeros with
different ·sign·s
are equal;
negative zeros are not ordered less than positive zeros.)
- INF is equal only to itself, and is greater than
−INF and all numerical precisionDecimal values.
- −INF is equal only to itself, and is less than
INF and all numerical precisionDecimal values.
- NaN is incomparable with all values, including
itself.
3.3.4.3
Facets
precisionDecimal has the following ·constraining facets·:
precisionDecimal 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:
Datatypes derived by
restriction from precisionDecimal may also
specify values for the
following·constraining facets·:
precisionDecimal has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = true
3.3.5 float
[Definition:] The
float datatype
is the IEEE
single-precision 32-bit floating point datatype
[IEEE 754-1985] with the minor exception
noted below.
Floating point numbers are certain subsets of the rational numbers, and are often used to
approximate arbitrary real numbers.
3.3.5.1 Value Space
The ·value space· of float contains the
non-zero numbers m × 2e ,
where m is an integer whose absolute value is less than 224,
and e 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 mapping· 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 distinct for purposes of enumerations and
identity constraints, but equal for purposes of 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: 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 754-1985].
3.3.5.2 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', and 'NaN'
The floatRep production is equivalent to this regular expression:
(-|+)?(([0-9]+(.[0-9]*)?)|(.[0-9]+))((e|E)(-|+)?[0-9]+)?|-?INF|NaN
The float datatype is designed to implement for schema
processing the single-precision floating-point datatype of
[IEEE 754-1985]. 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·, satisfies the requirements of
[IEEE 754-1985], and correctly handles the special values
(numericalSpecialRep ·literals·),
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 754-1985].
3.3.5.3
Facets
float has the following ·constraining facets·:
float 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:
Datatypes derived by
restriction from float may also
specify values for the
following·constraining facets·:
float has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = true
- cardinality = finite
- numeric = true
3.3.6 double
[Definition:] The double
datatype is the
IEEE double-precision 64-bit floating point datatype
[IEEE 754-1985] with the minor exception
noted below.
Floating point numbers are certain subsets of the rational numbers, and 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).
3.3.6.1 Value Space
The ·value space· of double contains the
non-zero numbers m × 2e ,
where m is an integer whose absolute value is less than 253,
and e 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 mapping· 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 distinct for purposes of enumerations and
identity constraints, but equal for purposes of 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: 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 754-1985].
3.3.6.2 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', and 'NaN'
The doubleRep production is equivalent to this regular expression:
(-|+)?(([0-9]+(.[0-9]*)?)|(.[0-9]+))((e|E)(-|+)?[0-9]+)?|-?INF|NaN
The double datatype is designed to implement for schema
processing the double-precision floating-point datatype of
[IEEE 754-1985]. 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·, satisfies the requirements of
[IEEE 754-1985], and correctly handles the special values
(numericalSpecialRep ·literals·),
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 754-1985].
3.3.6.3
Facets
double has the following ·constraining facets·:
double 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:
Datatypes derived by
restriction from double may also
specify values for the
following·constraining facets·:
double has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = true
- cardinality = finite
- numeric = true
3.3.7 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
a duration value; "15 days beginning 12 July
1995" and "15 days ending 12 July 1995" are
not. 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·.
3.3.7.1 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.
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: 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.
3.3.7.2 Lexical Space
The ·lexical representations·
of duration are
more or less based on the pattern:
PnYnMnDTnHnMnS
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
Thus, a durationLexicalRep consists of one or more of a duYearFrag,
duMonthFrag, duDayFrag, duHourFrag,
duMinuteFrag, and/or duSecondFrag, in order, with letters
'P' and 'T' (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]*)?)|(.[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 'T' is not the final character, so that
if 'T' appears, something follows it. The first rule
ensures that what follows 'T' 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]+M) ) )(([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) ) )) ) )?)|
( (([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·.
3.3.7.3
Facets
duration has the following ·constraining facets·:
duration 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:
Datatypes derived by
restriction from duration may also
specify values for the
following·constraining facets·:
duration has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.8 dateTime
dateTime represents
instants of time, optionally marked
with a particular timezone. Values representing
the same instant but having
different timezones are equal but not
identical.
3.3.8.1 Value Space
dateTime uses the
date/timeSevenPropertyModel, with no properties
except ·timezone·
permitted
to be absent. The ·timezone· property remains
·optional·.
Note: In version 1.0 of this specification, the
·year· property was not permitted to have the value
zero. The year 1 BCE was represented by a
·year· value of −1, 2 BCE by −2, and so
forth. 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.
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; caution should be used if existing
schemas or data specify dates of 29 February for any years before the
common era. With that possible exception, schemas and data valid
under the old interpretation remain valid under the new.
Constraint: Day-of-month ValuesThe
·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 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
(§C)
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
·timezone·
with another value whose
·timezone· is
absent is determined
by imputing timezones of both +14:00
and −14:00 to the untimezoned value, many such
combinations will be
·incomparable· because the two imputed
timezones 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, timezones. 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 timezones, equal
values with different
·timezone·s
are not
identical, and values with extreme
·timezone·s may no longer be equal
to any value with a smaller
·timezone·.
3.3.8.2 Lexical Mappings
The lexical representations for dateTime are as follows:
Constraint: Day-of-month RepresentationsWithin a
dateTimeLexicalRep, a
dayFrag must not
begin with the digit '
3' 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 '
0' digits are prohibited except to bring the
digit count up to four.
It represents the ·year· value. - Subsequent '
-', 'T', 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.
- dayFrag 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 the timezone in which
the moment occurs. Timezones 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.
'
Z' is an alternative representation of the timzone of
UTC, 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.
The dateTimeLexicalRep production
is equivalent to this regular expression
once whitespace is removed.
\-?([1-9][0-9][0-9][0-9]+)|(0[0-9][0-9][0-9])\-(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+)?)
([+\-](0[0-9])|(1[0-4]):[0-5][0-9])?
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·.
3.3.8.3
Facets
dateTime has the following ·constraining facets·:
dateTime 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:
Datatypes derived by
restriction from dateTime may also
specify values for the
following·constraining facets·:
dateTime has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.9 time
time
represents instants of time that recur at the same point in each
calendar day, or that occur in some arbitrary calendar day.
3.3.9.1 Value Space
time uses the date/timeSevenPropertyModel, with
·year·, ·month·,
and ·day· required
to be absent. ·timezone· remains
·optional·.
Note: See the conformance note in
(§C)
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 ·timezone·.
A calendar ( or "local time") day with an early
timezone begins earlier than the same calendar day with a later
timezone. Since the timezones allowed spread over 28 hours,
there are timezone pairs for which a given calendar day in the two
timezones are totally disjoint—the earlier day ends before the
same day starts in the later timezone. 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 timezone to the
end of that day in the −14:00 timezone.
Note: Since the order of a
time value
having a
·timezone·
with another value whose
·timezone·
is
absent is determined
by imputing timezones of both +14:00 and −14:00
to the untimezoned value, many such combinations will be
·incomparable· because the two imputed
timezones yield different orders. However,
for a given untimezoned 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 24 hours wide).
Examples that show the difference from version 1.0 of this specification (see
Lexical Mappings (§3.3.9.2) for the notations):
- A day is a calendar (or "local
time") day in each timezone.
08:00:00+10:00 < 17:00:00+10:00
(just as 08:00:00Z has always been less than
17:00:00Z, but in version 1.0
08:00:00+10:00 > 17:00:00+10:00 )
- A time value in a calendar day with an early timezone
may precede every value in a later calendar day:00:00:00+01:00 is less than every value with
·timezone· Z
- A calendar day with a very early timezone may be completely
disjoint from a calendar day with a very late timezone:Each value with ·timezone·
+13:00 is less than every
value with ·timezone· −13:00
- time values do not always
convert to ·UTC·
in the same way as in 1.0, since a time
in a timezone may convert to
a ·UTC· time on
a different day (whereas time
conversions in version 1.0 "wrapped around"
by ignoring the day during conversion):
22:00:00Z > 03:00:00+05:00
(since 1971-12-31T03:00:00+05 is 1979-12-30T22:00:00Z,
not 1979-12-31T22:00:00Z); in the previous
version of this specification 22:00:00Z =
03:00:00+05:00 )
3.3.9.2 Lexical Mappings
The lexical representations for time
are "projections" of
those of dateTime, as follows:
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[0-4]):[0-5][0-9]))?
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·.
3.3.9.3
Facets
time has the following ·constraining facets·:
time 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:
Datatypes derived by
restriction from time may also
specify values for the
following·constraining facets·:
time has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.10 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 (in
each timezone), up to but not including the beginning
moment of the next day). For nontimezoned values, the top-open
intervals disjointly cover the nontimezoned timeline,
one per day. For timezoned
values, the intervals begin at every minute and therefore overlap.
3.3.10.1 Value Space
date uses the date/timeSevenPropertyModel, with
·hour·, ·minute·,
and ·second· required
to be absent. ·timezone· remains
·optional·.
Constraint: Day-of-month ValuesThe
·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 divisble 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
(§C)
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 timezone explicitly, but for timezones not too far from
·UTC· their timezone could be recovered based on
their value's first moment on the timeline. The
date/timeSevenPropertyModel retains all timezones.
Examples that show the difference from version 1.0 (see
Lexical Mappings (§3.3.10.2) for the notations):
- A day is a calendar (or "local
time") day in each timezone,
including the timezones outside of +12:00 through -11:59 inclusive:2000-12-12+13:00 < 2000-12-12+11:00
(just as 2000-12-12+12:00 has always been less than
2000-12-12+11:00, but in version 1.0
2000-12-12+13:00 > 2000-12-12+11:00 ,
since 2000-12-12+13:00's "recoverable
timezone" was −11:00)
- Similarly:2000-12-12+13:00 = 2000-12-13−11:00
(whereas under 1.0, as just
stated, 2000-12-12+13:00 = 2000-12-12−11:00)
3.3.10.2 Lexical Mappings
The lexical representations for date
are "projections" of
those of dateTime, as follows:
Constraint: Day-of-month RepresentationsWithin a
dateLexicalRep,
a
dayFrag must not
begin with the digit '
3' 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][0-9][0-9]+)|(0[0-9][0-9][0-9])\-(0[1-9])|(1[0-2])\-([0-2][0-9])|(3[01])((+|\-)(0[0-9]|1[0-4]):[0-5][0-9])?
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·.
3.3.11 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.
3.3.11.1 Value Space
gYearMonth uses the date/timeSevenPropertyModel, with
·day·, ·hour·,
·minute·, and ·second· required
to be absent. ·timezone· remains
·optional·.
Note: See the conformance note in
(§C)
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,
gYearMonth
values did not
retain a timezone explicitly, but timezones not too far from
·UTC·
could be recovered based on the
gYearMonth
value's first moment on the timeline. The
date/timeSevenPropertyModel simply retains all timezones.
An example that shows the difference from version 1.0 (see
Lexical
Mappings (§3.3.11.2) for the notations):
- A day is a calendar (or "local time") day in
each timezone, including the timezones outside of +12:00 through
−11:59 inclusive:2000-12+13:00 < 2000-12+11:00
(just as 2000-12+12:00 has always been less than 2000−12+11:00,
but in version 1.0 2000-12+13:00 >
2000-12+11:00 , since 2000−12+13:00's "recoverable
timezone" was −11:00)
3.3.11.3
Facets
gYearMonth has the following ·constraining facets·:
gYearMonth 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:
Datatypes derived by
restriction from gYearMonth may also
specify values for the
following·constraining facets·:
gYearMonth has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.12 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.
3.3.12.1 Value Space
gYear uses the date/timeSevenPropertyModel, with
·month·, ·day·, ·hour·,
·minute·, and ·second· required
to be absent. ·timezone· remains
·optional·.
Note: See the conformance note in
(§C)
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,
gYear
values did not
retain a timezone explicitly, but timezones not too far from
·UTC·
could be recovered based on the
gYear
value's first moment on the timeline. The
date/timeSevenPropertyModel simply retains all timezones.
An example that shows the difference from version 1.0 (see
Lexical
Mappings (§3.3.12.2) for the notations):
- A day is a calendar (or "local time") day in
each timezone, including the timezones outside of +12:00 through
−11:59 inclusive:2000+13:00 < 2000+11:00
(just as 2000+12:00 has always been less than 2000+11:00,
but in version 1.0 2000+13:00 >
2000+11:00 , since 2000+13:00's "recoverable
timezone" was −11:00)
3.3.12.2 Lexical
Mappings
The lexical representations for
gYear are "projections" of
those of dateTime, as follows:
The gYearLexicalRep is equivalent to this regular expression:
\-?([1-9][0-9][0-9][0-9]+)|(0[0-9][0-9][0-9])((+|\-)(0[0-9]|1[0-4]):[0-5][0-9])?
The lexical mapping
for gYear is ·gYearLexicalMap·.
The canonical mapping
is ·gYearCanonicalMap·.
3.3.12.3
Facets
gYear has the following ·constraining facets·:
gYear 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:
Datatypes derived by
restriction from gYear may also
specify values for the
following·constraining facets·:
gYear has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.13 gMonthDay
gMonthDay represents whole calendar
days that recur at the same point in each calendar year, or that occur
in some arbitrary calendar year.
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.
3.3.13.1 Value Space
gMonthDay uses the date/timeSevenPropertyModel, with
·year·, ·hour·, ·minute·, and ·second· required
to be absent. ·timezone· remains
·optional·.
Constraint: Day-of-month ValuesThe
·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 timezone explicitly, but for timezones not too far from
·UTC· their timezone could be recovered based on
their value's first moment on the timeline. The
date/timeSevenPropertyModel retains all timezones.
An example that shows the difference from version 1.0 (see
Lexical
Mappings (§3.3.13.2) for the notations):
- A day is a calendar (or "local time") day in each timezone,
including the timezones outside of +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
timezone" was −11:00)
3.3.13.3
Facets
gMonthDay has the following ·constraining facets·:
gMonthDay 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:
Datatypes derived by
restriction from gMonthDay may also
specify values for the
following·constraining facets·:
gMonthDay has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.14 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.
3.3.14.1 Value Space
gDay uses the date/timeSevenPropertyModel, with
·year·, ·month·,
·hour·, ·minute·,
and ·second· required to be
absent. ·timezone· 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
·timezone· values
differ by at least 24
hours. (It is possible for ·timezone·
values to differ by up to 28 hours.)
Examples that may appear anomalous (see Lexical Mappings (§3.3.14.2) 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:
Timezones do not cause wrap-around at the end of the month:
the last day of a
given month in timezone −13:00 may start after the first
day of the next month in timezone +13:00, as
measured on the global timeline,
but nonetheless
---01+13:00 < ---31−13:00 .
3.3.14.2 Lexical Mappings
The lexical representations for gDay are
"projections"
of those of dateTime, as follows:
The gDayLexicalRep is equivalent to this regular expression:
\-\-\-([0-2][0-9]|3[01])((+|\-)(0[0-9]|1[0-4]):[0-5][0-9])?
The lexical mapping
for gDay is ·gDayLexicalMap·.
The canonical mapping is ·gDayCanonicalMap·.
3.3.14.3
Facets
gDay has the following ·constraining facets·:
gDay 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:
Datatypes derived by
restriction from gDay may also
specify values for the
following·constraining facets·:
gDay has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.15 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.
3.3.15.1 Value Space
gMonth uses the date/timeSevenPropertyModel, with
·year·, ·day·, ·hour·, ·minute·, and ·second· required
to be absent. ·timezone· remains
·optional·.
Equality and order are as prescribed in
The Seven-property Model (§D.2.1).
Note: In version 1.0 of this specification,
gMonth values
did not retain a timezone explicitly, but for timezones not too far from
·UTC· their timezone could be recovered based on
their value's first moment on the timeline. The
date/timeSevenPropertyModel retains all timezones.
An example that shows the difference from version 1.0 (see
Lexical
Mappings (§3.3.15.2) for the notations):
- A month is a calendar (or "local time") month in each timezone,
including the timezones outside of +12:00 through −11:59 inclusive:--12+13:00 < --12+11:00
(just as --12+12:00 has always been less than --12+11:00, but in version 1.0
--12+13:00 > --12+11:00 , since --12+13:00's "recoverable
timezone" was −11:00)
3.3.15.3
Facets
gMonth has the following ·constraining facets·:
gMonth 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:
Datatypes derived by
restriction from gMonth may also
specify values for the
following·constraining facets·:
gMonth has the
following values for its ·fundamental facets·:
- ordered = partial
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.16 hexBinary
[Definition:]
hexBinary represents
arbitrary hex-encoded binary data. The ·value space· of
hexBinary is the set of finite-length sequences of binary
octets.
3.3.16.1 Lexical Representation
hexBinary has a lexical representation where
each binary octet is encoded as a character tuple, consisting of two
hexadecimal digits ([0-9a-fA-F]) representing the octet code. For example,
"0FB7" is a hex encoding for the 16-bit integer 4023
(whose binary representation is 111110110111).
3.3.16.2 Canonical Representation
The canonical representation for hexBinary is defined
by prohibiting certain options from the
Lexical Representation (§3.3.16.1). Specifically, the lower case
hexadecimal digits ([a-f]) are not allowed.
3.3.16.3
Facets
hexBinary has the following ·constraining facets·:
hexBinary 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:
Datatypes derived by
restriction from hexBinary may also
specify values for the
following·constraining facets·:
hexBinary has the
following values for its ·fundamental facets·:
- ordered = false
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.17 base64Binary
[Definition:]
base64Binary
represents Base64-encoded arbitrary binary data. The ·value space· of
base64Binary is the set of finite-length sequences of binary
octets. 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].
The lexical forms 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 characters defined in [XML] as white space.
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 forms of base64Binary
data. It
must not
be enforced by XML Schema processors.
The lexical space of base64Binary is given by the following grammar
(the notation is that used in [XML]); legal lexical forms must match
the Base64Binary production.
Base64Binary ::= ((B64S B64S B64S B64S)*
((B64S B64S B64S B64) |
(B64S B64S B16S '=') |
(B64S B04S '=' #x20? '=')))?
B64S ::= B64 #x20?
B16S ::= B16 #x20?
B04S ::= B04 #x20?
B04 ::= [AQgw]
B16 ::= [AEIMQUYcgkosw048]
B64 ::= [A-Za-z0-9+/]
Note that this grammar requires the number of non-whitespace characters in the lexical
form to be a multiple of four, and for equals signs to appear only at the end of the
lexical form; strings which do not meet these constraints are not legal lexical forms
of base64Binary because they cannot successfully be decoded by base64
decoders.
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 form of a base64Binary data value is the base64
encoding of the value which matches the Canonical-base64Binary production in the following
grammar:
Canonical-base64Binary ::= (B64
B64 B64 B64)*
((B64 B64 B16 '=') | (B64 B04 '=='))?
Note: For some values the canonical form 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 is the number of octets it contains.
This may be calculated from the lexical form 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]
3.3.17.1
Facets
base64Binary has the following ·constraining facets·:
base64Binary 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:
Datatypes derived by
restriction from base64Binary may also
specify values for the
following·constraining facets·:
base64Binary has the
following values for its ·fundamental facets·:
- ordered = false
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.18 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 URI reference escaping procedure defined 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).
3.3.18.1 Lexical mapping
The ·lexical space· of anyURI is
finite-length
character sequences.
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.
3.3.18.2
Facets
anyURI has the following ·constraining facets·:
anyURI 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:
Datatypes derived by
restriction from anyURI may also
specify values for the
following·constraining facets·:
anyURI has the
following values for its ·fundamental facets·:
- ordered = false
- bounded = false
- cardinality = countably infinite
- numeric = false
3.3.20 NOTATION
[Definition:] NOTATION
represents the NOTATION
attribute
type from [XML].
The ·value space·
of NOTATION is the set of QNames
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
QNames).
Schema Component Constraint: enumeration facet value required for NOTATION
It is an
·error· for
NOTATION
to be used directly in a schema. Only datatypes that are
·derived· from
NOTATION by
specifying a value for
·enumeration· can be used
in a schema.
For compatibility (see Terminology (§1.5))
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.
3.4 Other Built-in Datatypes
This section gives conceptual definitions for all
·built-in· ·ordinary·
datatypes defined by this specification. The XML representation used to define
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
normalizedString has the following ·constraining facets·:
normalizedString has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from normalizedString may also
specify values for the
following·constraining facets·:
normalizedString 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·
datatypes are
·derived·
from
normalizedString:
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
token has the following ·constraining facets·:
token has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from token may also
specify values for the
following·constraining facets·:
token has the
following values for its ·fundamental facets·:
- ordered = false
- bounded = false
- cardinality = countably infinite
- numeric = false
3.4.3 language
[Definition:]
language
represents formal
natural language identifiers,
as defined
by [RFC 3066]or its
successor(s) in the IETF Standards Track.
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].
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
[RFC 3066]
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: [RFC 3066] specifies that
language codes "are to be treated as case insensitive; there
exist conventions for capitalization of some of them, but these should
not be taken to carry meaning. For instance, [ISO 3166] recommends
that country codes are capitalized (MN Mongolia), while [ISO 639]
recommends that language codes are written in lower case (mn
Mongolian)." 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' 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
[RFC 3066] does not follow from the definition of
this datatype given here; applications which require
case-sensitivity should make appropriate adjustments.
3.4.3.1
Facets
language has the following ·constraining facets·:
language has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from language may also
specify values for the
following·constraining facets·:
language 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 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
integer has the following ·constraining facets·:
integer 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:
integer has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from integer may also
specify values for the
following·constraining facets·:
integer has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = false
- cardinality = countably infinite
- numeric = true
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 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
nonPositiveInteger has the following ·constraining facets·:
nonPositiveInteger 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:
nonPositiveInteger has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from nonPositiveInteger may also
specify values for the
following·constraining facets·:
nonPositiveInteger 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·
datatypes are
·derived·
from
nonPositiveInteger:
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 finite-length
sequence of decimal digits (#x30-#x39). 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
negativeInteger has the following ·constraining facets·:
negativeInteger 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:
negativeInteger has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from negativeInteger may also
specify values for the
following·constraining facets·:
negativeInteger 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 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
long has the following ·constraining facets·:
long 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:
long has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from long may also
specify values for the
following·constraining facets·:
long has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = true
- cardinality = finite
- numeric = true
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 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
int has the following ·constraining facets·:
int 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:
int has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from int may also
specify values for the
following·constraining facets·:
int has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = true
- cardinality = finite
- numeric = true
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 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
short has the following ·constraining facets·:
short 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:
short has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from short may also
specify values for the
following·constraining facets·:
short has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = true
- cardinality = finite
- numeric = true
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 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
byte has the following ·constraining facets·:
byte 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:
byte has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from byte may also
specify values for the
following·constraining facets·:
byte 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 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
nonNegativeInteger has the following ·constraining facets·:
nonNegativeInteger 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:
nonNegativeInteger has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from nonNegativeInteger may also
specify values for the
following·constraining facets·:
nonNegativeInteger 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:
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 a finite-length sequence of decimal digits (#x30-#x39).
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
unsignedLong has the following ·constraining facets·:
unsignedLong 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:
unsignedLong has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from unsignedLong may also
specify values for the
following·constraining facets·:
unsignedLong has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = true
- cardinality = finite
- numeric = true
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 a finite-length
sequence of decimal digits (#x30-#x39). 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
unsignedInt has the following ·constraining facets·:
unsignedInt 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:
unsignedInt has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from unsignedInt may also
specify values for the
following·constraining facets·:
unsignedInt has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = true
- cardinality = finite
- numeric = true
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 a finite-length
sequence of decimal digits (#x30-#x39).
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
unsignedShort has the following ·constraining facets·:
unsignedShort 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:
unsignedShort has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from unsignedShort may also
specify values for the
following·constraining facets·:
unsignedShort 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·
datatypes are
·derived·
from
unsignedShort:
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 a finite-length
sequence of decimal digits (#x30-#x39).
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
unsignedByte has the following ·constraining facets·:
unsignedByte 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:
unsignedByte has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from unsignedByte may also
specify values for the
following·constraining facets·:
unsignedByte 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 finite-length
sequence of decimal digits (#x30-#x39).
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
positiveInteger has the following ·constraining facets·:
positiveInteger 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:
positiveInteger has the
following ·constraining facets· with the values shown; these
facets may be further restricted in the derivation of new types:
Datatypes derived by
restriction from positiveInteger may also
specify values for the
following·constraining facets·:
positiveInteger has the
following values for its ·fundamental facets·:
- ordered = total
- bounded = false
- cardinality = countably infinite
- numeric = true