XPath and XQuery Functions and Operators 4.0

2 Processing sequences

A sequence is an ordered collection of zero or more items. An item is a node, an atomic item, or a function, such as a map or an array. The terms sequence and item are defined formally in [XQuery 4.0: An XML Query Language] and [XML Path Language (XPath) 4.0].

2.4 Aggregate functions

Aggregate functions take a sequence as argument and return a single value computed from values in the sequence. Except for fn:count, the sequence must consist of values of a single type or one if its subtypes, or they must be numeric. xs:untypedAtomic values are permitted in the input sequence and handled by special conversion rules. The type of the items in the sequence must also support certain operations.

Function	Meaning
`fn:count`	Returns the number of items in a sequence.
`fn:all-equal`	Returns `true` if all items in a supplied sequence (after atomization) are equal.
`fn:all-different`	Returns `true` if no two items in a supplied sequence are equal.
`fn:avg`	Returns the average of the values in the input sequence `$values`, that is, the sum of the values divided by the number of values.
`fn:max`	Returns a value that is equal to the highest value appearing in the input sequence.
`fn:min`	Returns a value that is equal to the lowest value appearing in the input sequence.
`fn:sum`	Returns a value obtained by adding together the values in `$values`.

2.4.5 fn:max

Changes in 4.0 ⬇ ⬆

The way that fn:min and fn:max compare numeric values of different types has changed. The most noticeable effect is that when these functions are applied to a sequence of xs:integer or xs:decimal values, the result is an xs:integer or xs:decimal, rather than the result of converting this to an xs:float or xs:double. [Issue 866 PR 881 6 December 2023]

Summary

Returns a value that is equal to the highest value appearing in the input sequence.

Signature

`fn:max`(
`$values`	`as` `xs:anyAtomicType*`,
`$collation`	`as` `xs:string?`	`:=` `fn:default-collation()`
) `as` `xs:anyAtomicType?`

Properties

The one-argument form of this function is deterministic, context-dependent, and focus-independent. It depends on collations, and implicit timezone.

The two-argument form of this function is deterministic, context-dependent, and focus-independent. It depends on collations, and static base URI, and implicit timezone.

Rules

Any item in $values that is an instance of xs:untypedAtomic is first cast to xs:double. The resulting sequence is referred to as the converted sequence.

All pairs of values in the converted sequence must be mutually comparable. Two values are mutually comparable if one or more of the following conditions applies:

Both values are instances of xs:string or xs:anyURI.
Both values are instances of xs:numeric.
Both values are instances of xs:hexBinary or xs:base64Binary.
Both values are instances of xs:date.
Both values are instances of xs:dateTime.
Both values are instances of xs:time.
Both values are instances of xs:dayTimeDuration.
Both values are instances of xs:yearMonthDuration.
Both values are instances of xs:boolean.

If the converted sequence contains a single value then it must be comparable to itself under the above rules. (So the input cannot be, for example, a singleton xs:QName.)

If the converted sequence is empty, the function returns the empty sequence.

If the converted sequence contains the value NaN, the value NaN is returned (as an xs:float or xs:double as appropriate).

Two items $v1 and $v2 from the converted sequence are compared as follows:

If both values are instances of xs:string or xs:anyURI, they are compared using fn:compare($v1, $v2, $collation), where $collation is determined by the rules in 5.3.7 Choosing a collation.
Note:
In other cases, $collation is ignored.
If both values are instances of xs:numeric, they are compared using fn:compare($v1, $v2).
In all other cases, the values are compared using the lt and eq operators appropriate to their type.

The result of the function is a value from the converted sequence that is greater than or equal to every other value under the above rules. If there is more than one such value, then it is implementation-dependent which of them is returned.

Error Conditions

A type error is raised [err:FORG0006] if the input sequence contains items of incompatible types, as described above.

Notes

If there are two or items that are “equal highest”, the specific item whose value is returned is implementation-dependent. This can arise for example if two different strings compare equal under the selected collation, or if two different xs:dateTime values compare equal despite being in different timezones.

If the converted sequence contains exactly one value then that value is returned.

The default type when the fn:max function is applied to xs:untypedAtomic values is xs:double. This differs from the default type for operators such as lt, and for sorting in XQuery and XSLT, which is xs:string.

In version 4.0, if $values is a sequence of xs:decimal values (including the case where it is a sequence of xs:integer values), then the result will be one of these xs:decimal or xs:integer values. In earlier versions it would be the result of converting this xs:decimal to xs:float or xs:double.

Examples

Expression	Result
`max((3, 2, 1))`	`3`
`max([ 3, 2, 1 ])`	`3` (Arrays are atomized).
`max(( xs:integer(5), xs:float(5), xs:double(0) ))`	`5` (The result may be either the `xs:integer` or the `xs:float`, since they are equal.)
`max(( xs:float(0.0E0), xs:float(-0.0E0) ))`	`xs:float(0.0e0)` (The result may be either positive or negative zero, since they are equal.)
`max(( current-date(), xs:date("2100-01-01") ))`	`xs:date("2100-01-01")` (Assuming that the current date is during the 21st century.)
`max(("a", "b", "c"))`	`"c"` (Assuming a typical default collation.)
`max((3, 4, "Zero"))` raises a type error [err:FORG0006].

2.4.6 fn:min

Changes in 4.0 ⬇ ⬆

The way that fn:min and fn:max compare numeric values of different types has changed. The most noticeable effect is that when these functions are applied to a sequence of xs:integer or xs:decimal values, the result is an xs:integer or xs:decimal, rather than the result of converting this to an xs:float or xs:double. [Issue 866 PR 881 6 December 2023]

Summary

Returns a value that is equal to the lowest value appearing in the input sequence.

Signature

`fn:min`(
`$values`	`as` `xs:anyAtomicType*`,
`$collation`	`as` `xs:string?`	`:=` `fn:default-collation()`
) `as` `xs:anyAtomicType?`

Properties

The one-argument form of this function is deterministic, context-dependent, and focus-independent. It depends on collations, and implicit timezone.

The two-argument form of this function is deterministic, context-dependent, and focus-independent. It depends on collations, and static base URI, and implicit timezone.

Rules

Any item in $values that is an instance of xs:untypedAtomic is first cast to xs:double. The resulting sequence is referred to as the converted sequence.

All pairs of values in the converted sequence must be mutually comparable. Two values are mutually comparable if one or more of the following conditions applies:

Both values are instances of xs:string or xs:anyURI.
Both values are instances of xs:numeric.
Both values are instances of xs:hexBinary or xs:base64Binary.
Both values are instances of xs:date.
Both values are instances of xs:dateTime.
Both values are instances of xs:time.
Both values are instances of xs:dayTimeDuration.
Both values are instances of xs:yearMonthDuration.
Both values are instances of xs:boolean.

If the converted sequence contains a single value then it must be comparable to itself under the above rules. (So the input cannot be, for example, a singleton xs:QName.)

If the converted sequence is empty, the function returns the empty sequence.

If the converted sequence contains the value NaN, the value NaN is returned (as an xs:float or xs:double as appropriate).

Two items $v1 and $v2 from the converted sequence are compared as follows:

If both values are instances of xs:string or xs:anyURI, they are compared using fn:compare($v1, $v2, $collation), where $collation is determined by the rules in 5.3.7 Choosing a collation.
Note:
In other cases, $collation is ignored.
If both values are instances of xs:numeric, they are compared using fn:compare($v1, $v2).
In all other cases, the values are compared using the lt and eq operators appropriate to their type.

The result of the function is a value from the converted sequence that is less than or equal to every other value under the above rules. If there is more than one such value, then it is implementation-dependent which of them is returned.

Error Conditions

A type error is raised [err:FORG0006] if the input sequence contains items of incompatible types, as described above.

Notes

If there are two or items that are “equal lowest”, the specific item whose value is returned is implementation-dependent. This can arise for example if two different strings compare equal under the selected collation, or if two different xs:dateTime values compare equal despite being in different timezones.

If the converted sequence contains exactly one value then that value is returned.

The default type when the fn:min function is applied to xs:untypedAtomic values is xs:double. This differs from the default type for operators such as lt, and for sorting in XQuery and XSLT, which is xs:string.

Examples

Expression	Result
`min((3, 4, 5))`	`3`
`min([ 3, 4, 5 ])`	`3` (Arrays are atomized).
`min(( xs:integer(5), xs:float(5), xs:double(10) ))`	`5` (The result may be either the `xs:integer` or the `xs:float`, since they are equal.)
`min(( xs:float(0.0E0), xs:float(-0.0E0) ))`	`xs:float(0.0e0)` (The result may be either positive or negative zero, since they are equal.)
`min(( current-date(), xs:date("1900-01-01") ))`	`xs:date("1900-01-01")` (Assuming that the current date is set to a reasonable value.)
`min(("a", "b", "c"))`	`"a"` (Assuming a typical default collation.)
`min((3, 4, "Zero"))` raises a type error [err:FORG0006].

2.5 Basic higher-order functions

The following functions take function items as an argument.

Function	Meaning
`fn:apply`	Makes a dynamic call on a function with an argument list supplied in the form of an array.
`fn:do-until`	Processes a supplied value repeatedly, continuing when some condition is false, and returning the value that satisfies the condition.
`fn:every`	Returns `true` if every item in the input sequence matches a supplied predicate.
`fn:filter`	Returns those items from the sequence `$input` for which the supplied function `$predicate` returns `true`.
`fn:fold-left`	Processes the supplied sequence from left to right, applying the supplied function repeatedly to each item in turn, together with an accumulated result value.
`fn:fold-right`	Processes the supplied sequence from right to left, applying the supplied function repeatedly to each item in turn, together with an accumulated result value.
`fn:for-each`	Applies the function item `$action` to every item from the sequence `$input` in turn, returning the concatenation of the resulting sequences in order.
`fn:for-each-pair`	Applies the function item `$action` to successive pairs of items taken one from `$input1` and one from `$input2`, returning the concatenation of the resulting sequences in order.
`fn:highest`	Returns those items from a supplied sequence that have the highest value of a sort key, where the sort key can be computed using a caller-supplied function.
`fn:index-where`	Returns the positions in an input sequence of items that match a supplied predicate.
`fn:lowest`	Returns those items from a supplied sequence that have the lowest value of a sort key, where the sort key can be computed using a caller-supplied function.
`fn:partial-apply`	Performs partial application of a function item by binding values to selected arguments.
`fn:partition`	Partitions a sequence of items into a sequence of non-empty arrays containing the same items, starting a new partition when a supplied condition is true.
`fn:scan-left`	Produces the sequence of successive partial results from the evaluation of `fn:fold-left` with the same arguments.
`fn:scan-right`	Produces the sequence of successive partial results from the evaluation of `fn:fold-right` with the same arguments.
`fn:some`	Returns `true` if at least one item in the input sequence matches a supplied predicate.
`fn:sort`	Sorts a supplied sequence, based on the value of a sort key supplied as a function.
`fn:sort-by`	Sorts a supplied sequence, based on the value of a number of sort keys supplied as functions.
`fn:sort-with`	Sorts a supplied sequence, according to the order induced by the supplied comparator functions.
`fn:subsequence-where`	Returns a contiguous sequence of items from `$input`, with the start and end points located by applying predicates.
`fn:take-while`	Returns items from the input sequence prior to the first one that fails to match a supplied predicate.
`fn:transitive-closure`	Returns all the GNodes reachable from a given start GNode by applying a supplied function repeatedly.
`fn:while-do`	Processes a supplied value repeatedly, continuing while some condition remains true, and returning the first value that does not satisfy the condition.

With all these functions, if the caller-supplied function fails with a dynamic error, this error is propagated as an error from the higher-order function itself.

2.5.8 fn:for-each-pair

Changes in 4.0 ⬇ ⬆

The $action callback function accepts an optional position argument. [Issue 516 PR 828 14 November 2023]

Summary

Applies the function item $action to successive pairs of items taken one from $input1 and one from $input2, returning the concatenation of the resulting sequences in order.

Signature

`fn:for-each-pair`(
`$input1`	`as` `item()*`,
`$input2`	`as` `item()*`,
`$action`	`as` `fn(item(), item(), xs:integer) as item()*`
) `as` `item()*`

Properties

This function is deterministic, context-independent, and focus-independent.

Rules

The function returns the value of the expression:

for $pos in 1 to min(count($input1), count($input2))
return $action($input1[$pos], $input2[$pos], $pos)

for $pos in 1 to min((count($input1), count($input2)))
return $action($input1[$pos], $input2[$pos], $pos)

Notes

If one sequence is longer than the other, excess items in the longer sequence are ignored.

Examples

Expression:	for-each-pair( ("a", "b", "c"), ("x", "y", "z"), concat#2 )
Result:	"ax", "by", "cz"
Expression:	for-each-pair( 1 to 5, 1 to 5, fn($a, $b) { 10 * $a + $b } )
Result:	11, 22, 33, 44, 55
Expression:	let $s := 1 to 8 return for-each-pair($s, tail($s), fn($a, $b) { $a * $b })
Result:	2, 6, 12, 20, 30, 42, 56
Expression:	for-each-pair( (1, 8, 2), (3, 4, 3), fn($item1, $item2, $pos) { $pos \|\| ': ' \|\| max(($item1, $item2)) } )
Result:	"1: 3", "2: 8", "3: 3"

H Changes since 3.1 (Non-Normative)

H.1 Summary of Changes

Use the arrows to browse significant changes since the 3.1 version of this specification.
See 1 Introduction
Sections with significant changes are marked Δ in the table of contents. New functions introduced in this version are marked ➕ in the table of contents.
See 1 Introduction
New in 4.0
See 2.1.9 fn:replicate
New in 4.0
See 2.1.12 fn:slice
New in 4.0. The function replaces the internal op:same-key function in 3.1
See 2.2.1 fn:atomic-equal
PR 1120 1150
A callback function can be supplied for comparing individual items.
See 2.2.4 fn:deep-equal
Changed in 4.0 to use transitive equality comparisons for numeric values.
See 2.2.5 fn:distinct-values
PR 614 987
New in 4.0
See 2.2.6 fn:duplicate-values
New in 4.0. Originally proposed under the name fn:uniform
See 2.4.2 fn:all-equal
New in 4.0. Originally proposed under the name fn:unique
See 2.4.3 fn:all-different
New in 4.0
See 2.5.3 fn:every
New in 4.0
See 2.5.9 fn:highest
New in 4.0
See 2.5.10 fn:index-where
New in 4.0
See 2.5.11 fn:lowest
New in 4.0
See 2.5.15 fn:scan-right
New in 4.0
See 2.5.16 fn:some
PR 795 2228
New in 4.0
See 2.5.19 fn:sort-with
PR 521 761
New in 4.0
See 2.5.22 fn:transitive-closure
New in 4.0
See 4.4.5 fn:is-NaN
PR 1260 1275
A third argument has been added, providing control over the rounding mode.
See 4.4.6 fn:round
PR 1049 1151
Decimal format parameters can now be supplied directly as a map in the third argument, rather than referencing a format defined in the static context.
See 4.7.2 fn:format-number
PR 1205 1230
New in 4.0
See 4.8.2 math:e
See 4.8.8 math:cosh
See 4.8.15 math:sinh
See 4.8.18 math:tanh
The 3.1 specification suggested that every value in the result range should have the same chance of being chosen. This has been corrected to say that the distribution should be arithmetically uniform (because there are as many xs:double values between 0.01 and 0.1 as there are between 0.1 and 1.0).
See 4.9.2 fn:random-number-generator
PR 261 306 993
New in 4.0
See 5.4.1 fn:char
New in 4.0
See 5.4.2 fn:characters
PR 937 995 1190
New in 4.0
See 5.4.13 fn:hash
New in 4.0
See 7.6.2 fn:parse-uri
PR 1423 1413
New in 4.0
See 7.6.3 fn:build-uri
New in 4.0
See 12.2.2 fn:in-scope-namespaces
Reformulated in 4.0 in terms of the new fn:in-scope-namespaces function; the semantics are unchanged.
See 12.2.3 fn:in-scope-prefixes
Reformulated in 4.0 in terms of the new fn:in-scope-namespaces function; the semantics are unchanged.
See 12.2.8 fn:namespace-uri-for-prefix
PR 1620 1886
Options are added to customize the form of the output.
See 12.2.9 fn:path
PR 1547 1551
New in 4.0
See 12.2.11 fn:siblings
New in 4.0
See 14.4.6 map:filter
New in 4.0
See 14.4.10 map:items
PR 478 515
New in 4.0
See 14.4.12 map:keys-where
PR 1575 1906
A new function fn:element-to-map is provided for converting XDM trees to maps suitable for serialization as JSON. Unlike the fn:xml-to-json function retained from 3.1, this can handle arbitrary XML as input.
See 14.5 Converting elements to maps
New in 4.0
See 15.2.3 array:empty
PR 968 1295
New in 4.0
See 15.2.13 array:index-of
PR 476 1087
New in 4.0
See 15.2.16 array:items
PR 360 476
New in 4.0
See 15.2.18 array:members
See 15.2.19 array:of-members
New in 4.0
See 15.2.24 array:slice
New in 4.0
See 15.2.28 array:split
Supplying an empty sequence as the value of an optional argument is equivalent to omitting the argument.
See 15.2.29 array:subarray
PR 1117 1279
The $options parameter has been added.
See 17.1.6 fn:unparsed-text-lines
New in 4.0
See 17.2.5 fn:xsd-validator
PR 259 956
A new function is available for processing input data in HTML format.
See 17.3 Functions on HTML Data
New in 4.0
See 17.3.2 fn:parse-html
PR 975 1058 1246
An option is provided to control how JSON numbers should be formatted.
See 17.4.4 fn:parse-json
Additional options are available, as defined by fn:parse-json.
See 17.4.5 fn:json-doc
PR 533 719 834 1066
New in 4.0
See 17.5.4 fn:csv-to-arrays
See 17.5.7 fn:parse-csv
PR 533 719 834 1066 1605
New in 4.0
See 17.5.10 fn:csv-to-xml
PR 791 1256 1282 1405
New in 4.0
See 17.6.1 fn:invisible-xml
PR 629 803
New in 4.0
See 21.2.2 fn:message
PR 533 719 834
New functions are available for processing input data in CSV (comma separated values) format.
See 17.5 Functions on CSV Data
Comparison of mixed numeric types (for example xs:double and xs:decimal) now generally converts both values to xs:decimal.
See 4.3 Comparing numeric values
PR 289 1901
A third argument is added, allowing user control of how absent keys should be handled.
See 14.4.9 map:get
A third argument is added, allowing user control of how index-out-of-bounds conditions should be handled.
See 15.2.11 array:get
A new collation URI is defined for Unicode case-insensitive comparison and ordering.
See 5.3.5 The Unicode case-insensitive collation
PR 1727 1740
It is no longer guaranteed that the new key replaces the existing key.
See 14.4.14 map:put
Generalized to work with JNodes as well as XNodes.
See 12.2.1 fn:has-children
The function is extended to handle JNodes.
See 12.2.9 fn:path
Generalized to work with JNodes as well as XNodes.
See 12.3.2 fn:innermost
See 12.3.3 fn:outermost
Atomic items of types xs:hexBinary and xs:base64Binary are now mutually comparable. In rare cases, where an application uses both types and assumes they are distinct, this can represent a backwards incompatibility.
See 2.2.1 fn:atomic-equal
See 2.2.4 fn:deep-equal
See 2.2.5 fn:distinct-values
PR 173
New in 4.0
See 18.4 fn:op
PR 203
New in 4.0
See 14.4.1 map:build
PR 207
New in 4.0
See 10.1.2 fn:parse-QName
See 10.2.5 fn:expanded-QName
PR 222
New in 4.0
See 2.2.3 fn:contains-subsequence
See 2.2.7 fn:ends-with-subsequence
See 2.2.9 fn:starts-with-subsequence
PR 250
New in 4.0
See 2.1.3 fn:foot
See 2.1.15 fn:trunk
See 15.2.2 array:build
See 15.2.8 array:foot
See 15.2.31 array:trunk
PR 258
New in 4.0
See 15.2.14 array:index-where
PR 313
The second argument can now be a sequence of integers.
See 2.1.8 fn:remove
PR 314
New in 4.0
See 14.4.4 map:entries
PR 326
Higher-order functions are no longer an optional feature.
See 1.2 Conformance
PR 419
New in 4.0
See 2.1.7 fn:items-at
PR 434
New in 4.0
See 4.5.2 fn:parse-integer
The function has been extended to allow output in a radix other than 10, for example in hexadecimal.
See 4.6.1 fn:format-integer
PR 482
Deleted an inaccurate statement concerning the behavior of NaN.
See 4.3 Comparing numeric values
PR 507
New in 4.0
See 2.5.13 fn:partition
PR 546
It is no longer automatically an error if the input contains a codepoint that is not valid in XML. Instead, the codepoint must be a permitted character. The set of permitted characters is implementation-defined, but it is recommended that all Unicode characters should be accepted.
See 5.2.1 fn:codepoints-to-string
It is no longer automatically an error if the resource (after decoding) contains a codepoint that is not valid in XML. Instead, the codepoint must be a permitted character. The set of permitted characters is implementation-defined, but it is recommended that all Unicode characters should be accepted.
See 17.1.5 fn:unparsed-text
The rules regarding use of non-XML characters in JSON texts have been relaxed.
See 17.4.3 JSON character repertoire
See 17.4.4 fn:parse-json
It is no longer automatically an error if the input contains a codepoint that is not valid in XML. Instead, the codepoint must be a permitted character. The set of permitted characters is implementation-defined, but it is recommended that all Unicode characters should be accepted.
See 17.4.5 fn:json-doc
PR 631
New in 4.0
See 7.1 fn:decode-from-uri
PR 662
Constructor functions now have a zero-arity form; the first argument defaults to the context item.
See 22 Constructor functions
PR 680
The case-insensitive collation is now defined normatively within this specification, rather than by reference to the HTML "living specification", which is subject to change. The collation can now be used for ordering comparisons as well as equality comparisons.
See 5.3.6 The HTML ASCII Case-Insensitive Collation
PR 702
The function can now take any number of arguments (previously it had to be two or more), and the arguments can be sequences of strings rather than single strings.
See 5.4.4 fn:concat
PR 710
Changes the function to return a sequence of key-value pairs rather than a map.
See 13.5 fn:function-annotations
PR 727
It has been clarified that loading a module has no effect on the static or dynamic context of the caller.
See 18.2 fn:load-xquery-module
PR 828
The $predicate callback function accepts an optional position argument.
See 2.5.4 fn:filter
The $action callback function accepts an optional position argument.
See 2.5.7 fn:for-each
See 2.5.8 fn:for-each-pair
The $predicate callback function now accepts an optional position argument.
See 15.2.4 array:filter
The $action callback function now accepts an optional position argument.
See 15.2.9 array:for-each
See 15.2.10 array:for-each-pair
PR 881
The way that fn:min and fn:max compare numeric values of different types has changed. The most noticeable effect is that when these functions are applied to a sequence of xs:integer or xs:decimal values, the result is an xs:integer or xs:decimal, rather than the result of converting this to an xs:float or xs:double.
See 2.4.5 fn:max
See 2.4.6 fn:min
PR 901
The optional third argument can now be supplied as an empty sequence.
See 2.1.13 fn:subsequence
The third argument can now be supplied as an empty sequence.
See 5.4.6 fn:substring
The second argument can now be an empty sequence.
See 6.3.3 fn:tokenize
The optional second argument can now be supplied as an empty sequence.
See 7.5 fn:resolve-uri
The 3rd, 4th, and 5th arguments are now optional; previously the function required either 2 or 5 arguments.
See 9.8.1 fn:format-dateTime
See 9.8.2 fn:format-date
See 9.8.3 fn:format-time
All three arguments are now optional, and each argument can be set to an empty sequence. Previously if $description was supplied, it could not be empty.
See 21.1.1 fn:error
The $label argument can now be set to an empty sequence. Previously if $label was supplied, it could not be empty.
See 21.2.1 fn:trace
PR 905
The rule that multiple calls on fn:doc supplying the same absolute URI must return the same document node has been clarified; in particular the rule does not apply if the dynamic context for the two calls requires different processing of the documents (such as schema validation or whitespace stripping).
See 17.1.1 fn:doc
PR 909
The function has been expanded in scope to handle comparison of values other than strings.
See 2.2.2 fn:compare
PR 924
Rules have been added clarifying that users should not be allowed to change the schema for the fn namespace.
See D Schemas
PR 925
The decimal format name can now be supplied as a value of type xs:QName, as an alternative to supplying a lexical QName as an instance of xs:string.
See 4.7.2 fn:format-number
PR 932
The specification now prescribes a minimum precision and range for durations.
See 8.1.2 Limits and precision
PR 933
When comments and processing instructions are ignored, any text nodes either side of the comment or processing instruction are now merged prior to comparison.
See 2.2.4 fn:deep-equal
PR 940
New in 4.0
See 2.5.20 fn:subsequence-where
PR 953
Constructor functions for named record types have been introduced.
See 22.6 Constructor functions for named record types
PR 962
New in 4.0
See 2.5.2 fn:do-until
See 2.5.23 fn:while-do
PR 969
New in 4.0
See 14.4.3 map:empty
PR 980
Atomic items of types xs:hexBinary and xs:base64Binary are now mutually comparable.
See 11.1.1 op:binary-equal
See 11.1.2 op:binary-less-than
PR 984
New in 4.0
See 8.4.1 fn:seconds
PR 987
The order of results is now prescribed; it was previously implementation-dependent.
See 2.2.5 fn:distinct-values
PR 1022
Regular expressions can include comments (starting and ending with #) if the c flag is set.
See 6.1 Regular expression syntax
See 6.2 Flags
PR 1028
An option is provided to control how the JSON null value should be handled.
See 17.4.4 fn:parse-json
PR 1032
New in 4.0
See 2.1.17 fn:void
PR 1046
New in 4.0
See 2.5.21 fn:take-while
PR 1059
Use of an option keyword that is not defined in the specification and is not known to the implementation now results in a dynamic error; previously it was ignored.
See 1.7 Options
PR 1068
New in 4.0
See 5.4.3 fn:graphemes
PR 1072
The return type is now specified more precisely.
See 18.2 fn:load-xquery-module
PR 1090
When casting from a string to a duration or time or dateTime, it is now specified that when there are more digits in the fractional seconds than the implementation is able to retain, excess digits are truncated. Rounding upwards (which could affect the number of minutes or hours in the value) is not permitted.
See 23.2 Casting from xs:string and xs:untypedAtomic
PR 1093
New in 4.0
See 5.3.9 fn:collation
PR 1117
The $options parameter has been added.
See 17.1.5 fn:unparsed-text
See 17.1.7 fn:unparsed-text-available
PR 1182
The $predicate callback function may return an empty sequence (meaning false).
See 2.5.2 fn:do-until
See 2.5.3 fn:every
See 2.5.4 fn:filter
See 2.5.10 fn:index-where
See 2.5.16 fn:some
See 2.5.21 fn:take-while
See 2.5.23 fn:while-do
See 14.4.6 map:filter
See 14.4.12 map:keys-where
See 15.2.4 array:filter
See 15.2.14 array:index-where
PR 1191
The $options parameter has been added, absorbing the $collation parameter.
See 2.2.4 fn:deep-equal
New in 4.0
See 12.3.1 fn:distinct-ordered-nodes
PR 1250
For selected properties including percent and exponent-separator, it is now possible to specify a single-character marker to be used in the picture string, together with a multi-character rendition to be used in the formatted output.
See 4.7.2 fn:format-number
PR 1257
The $options parameter has been added.
See 17.2.1 fn:parse-xml
See 17.2.2 fn:parse-xml-fragment
PR 1262
New in 4.0
See 5.3.10 fn:collation-available
PR 1265
The constraints on the result of the function have been relaxed.
See 12.1.2 fn:document-uri
PR 1280
As a result of changes to the coercion rules, the number of supplied arguments can be greater than the number required: extra arguments are ignored.
See 2.5.1 fn:apply
PR 1288
Additional error conditions have been defined.
See 17.2.1 fn:parse-xml
PR 1296
New in 4.0
See 2.5.14 fn:scan-left
PR 1333
A new option is provided to allow the content of the loaded module to be supplied as a string.
See 18.2 fn:load-xquery-module
PR 1353
An option has been added to suppress the escaping of the solidus (forwards slash) character.
See 17.4.7 fn:xml-to-json
PR 1358
New in 4.0
See 9.3.2 fn:unix-dateTime
PR 1361
The term atomic value has been replaced by atomic item.
See 1.9 Terminology
PR 1393
Changes the function to return a sequence of key-value pairs rather than a map.
See 13.5 fn:function-annotations
PR 1409
This section now uses the term primitive type strictly to refer to the 20 atomic types that are not derived by restriction from another atomic type: that is, the 19 primitive atomic types defined in XSD, plus xs:untypedAtomic. The three types xs:integer, xs:dayTimeDuration, and xs:yearMonthDuration, which have custom casting rules but are not strictly-speaking primitive, are now handled in other subsections.
See 23.1 Casting from primitive types to primitive types
The rules for conversion of dates and times to strings are now defined entirely in terms of XSD 1.1 canonical mappings, since these deliver exactly the same result as the XPath 3.1 rules.
See 23.1.2.2 Casting date/time values to xs:string
The rules for conversion of durations to strings are now defined entirely in terms of XSD 1.1 canonical mappings, since the XSD 1.1 rules deliver exactly the same result as the XPath 3.1 rules.
See 23.1.2.3 Casting xs:duration values to xs:string
PR 1455
Numbers now retain their original lexical form, except for any changes needed to satisfy JSON syntax rules (for example, stripping leading zero digits).
See 17.4.7 fn:xml-to-json
PR 1473
New in 4.0
See 2.1.5 fn:identity
PR 1481
The function has been extended to handle other Gregorian types such as xs:gYearMonth.
See 9.5.1 fn:year-from-dateTime
See 9.5.2 fn:month-from-dateTime
The function has been extended to handle other Gregorian types such as xs:gMonthDay.
See 9.5.3 fn:day-from-dateTime
The function has been extended to handle other types including xs:time.
See 9.5.4 fn:hours-from-dateTime
See 9.5.5 fn:minutes-from-dateTime
The function has been extended to handle other types such as xs:gYearMonth.
See 9.5.7 fn:timezone-from-dateTime
PR 1504
New in 4.0
See 2.1.11 fn:sequence-join
Optional $separator added.
See 15.2.17 array:join
PR 1523
New functions are provided to obtain information about built-in types and types defined in an imported schema.
See 19 Processing types
New in 4.0
See 19.1.2 fn:schema-type
See 19.1.4 fn:atomic-type-annotation
See 19.1.5 fn:node-type-annotation
PR 1545
New in 4.0
See 9.6.4 fn:civil-timezone
PR 1565
The default for the escape option has been changed to false. The 3.1 specification gave the default value as true, but this appears to have been an error, since it was inconsistent with examples given in the specification and with tests in the test suite.
See 17.4.4 fn:parse-json
PR 1570
New in 4.0
See 19.1.3 fn:type-of
PR 1587
New in 4.0
See 17.1.8 fn:unparsed-binary
PR 1611
The spec has been corrected to note that the function depends on the implicit timezone.
See 2.2.2 fn:compare
PR 1671
New in 4.0.
See 4.4.3 fn:divide-decimals
PR 1703
Ordered maps are introduced.
See 14.1 Ordering of Maps
Enhanced to allow for ordered maps.
See 14.4.6 map:filter
See 14.4.7 map:find
See 14.4.8 map:for-each
See 14.4.14 map:put
See 14.4.15 map:remove
The order of entries in maps is retained.
See 17.4.4 fn:parse-json
PR 1711
It is explicitly stated that the limits for $precision are implementation-defined.
See 4.4.6 fn:round
See 4.4.7 fn:round-half-to-even
PR 1727
For consistency with the new function map:build, the handling of duplicates may now be controlled by supplying a user-defined callback function as an alternative to the fixed values for the earlier duplicates option.
See 14.4.13 map:merge
PR 1734
In 3.1, given a mixed input sequence such as (1, 3, 4.2e0), the specification was unclear whether it was permitted to add the first two integer items using integer arithmetic, rather than converting all items to doubles before performing any arithmetic. The 4.0 specification is clear that this is permitted; but since the items can be reordered before being added, this is not required.
See 2.4.4 fn:avg
See 2.4.7 fn:sum
PR 1825
New in 4.0
See 2.5.12 fn:partial-apply
PR 1856
Word boundaries can be matched. Lookahead and lookbehind assertions are supported. Assertions (including ^ and $) can no longer be followed by a quantifier.
See 6.1 Regular expression syntax
It is now permitted for the regular expression to match a zero-length string.
See 6.3.2 fn:replace
See 6.3.3 fn:tokenize
The output of the function is extended to allow the represention of captured groups found within lookahead assertions.
See 6.3.4 fn:analyze-string
It is now permitted for the regular expression to match a zero-length string.
See 6.3.4 fn:analyze-string
PR 1879
Additional options to control DTD and XInclude processing have been added.
See 17.2.1 fn:parse-xml
PR 1897
The $replacement argument can now be a function that computes the replacement strings.
See 6.3.2 fn:replace
PR 1906
New in 4.0
See 14.5.10 fn:element-to-map-plan
New in 4.0.
See 14.5.11 fn:element-to-map
PR 1910
An $options parameter is added. Note that the rules for the $options parameter control aspects of processing that were implementation-defined in earlier versions of this specification. An implementation may provide configuration options designed to retain backwards-compatible behavior when no explicit options are supplied.
See 17.1.1 fn:doc
See 17.1.2 fn:doc-available
PR 1991
Named record types used in the signatures of built-in functions are now available as standard in the static context.
See C Built-in named record types
PR 2001
New in 4.0.
See 2.5.18 fn:sort-by
See 15.2.26 array:sort-by
PR 2013
Support for binary input has been added.
See 17.2.1 fn:parse-xml
See 17.2.2 fn:parse-xml-fragment
New in 4.0
See 17.3.3 fn:html-doc
See 17.5.8 fn:csv-doc
PR 2030
This description of the XSD validation process was previously found (with some duplication) in the XQuery and XSLT specifications; those specifications now reference this description. As a side-effects, the descriptions of the process in XQuery and XSLT are better aligned.
See 17.2.4 XSD validation
PR 2031
Introduced the concept of JNodes.
See 16 Processing JNodes
New in 4.0
See 16.1.1 fn:jtree
See 16.1.3 fn:jnode-selector
See 16.1.4 fn:jnode-position
PR 2218
The rules for numeric comparison of mixed types are changed to be fully transitive.
See 4.3.1 op:numeric-equal
See 4.3.2 op:numeric-less-than
PR 2223
An error may now be raised if the base URI is not a valid LEIRI reference.
See 12.1.1 fn:base-uri
PR 2224
The $action callback function now accepts an optional position argument.
See 14.4.6 map:filter
See 14.4.8 map:for-each
PR 2228
New in 4.0
See 15.2.27 array:sort-with
PR 2248
The specification now describes in more detail how to determine the effective encoding value.
See 17.1.5 fn:unparsed-text

XPath and XQuery Functions and Operators 4.0

W3C Editor's Draft 23 February 2026

Abstract

Status of this Document

Dedication

2 Processing sequences

2.4 Aggregate functions

2.4.5 fn:max

2.4.6 fn:min

2.5 Basic higher-order functions

2.5.8 fn:for-each-pair

H Changes since 3.1 (Non-Normative)

H.1 Summary of Changes