Difference between revisions of "Utility Module"
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− | This [[Module Library|XQuery Module]] contains various | + | This [[Module Library|XQuery Module]] contains various utility and helper functions. |
+ | |||
+ | For all listed functions, equivalent expressions exist in standard XQuery, but code may be better readable with function calls: | ||
+ | |||
+ | <syntaxhighlight lang="xquery"> | ||
+ | (: standard XQuery :) | ||
+ | let $result := if(exists($sequence)) then $sequence else ('default', 'values') | ||
+ | return $result[last()] | ||
+ | |||
+ | (: XQuery with functions of this module :) | ||
+ | $sequence | ||
+ | => util:or(('default', 'values')) | ||
+ | => util:last() | ||
+ | </syntaxhighlight> | ||
+ | |||
+ | In addition, various query optimizations create calls to the utility functions. | ||
=Conventions= | =Conventions= | ||
Line 5: | Line 20: | ||
All functions and errors in this module and errors are assigned to the <code><nowiki>http://basex.org/modules/util</nowiki></code> namespace, which is statically bound to the {{Code|util}} prefix.<br/> | All functions and errors in this module and errors are assigned to the <code><nowiki>http://basex.org/modules/util</nowiki></code> namespace, which is statically bound to the {{Code|util}} prefix.<br/> | ||
− | = | + | =Conditions= |
+ | |||
+ | ==util:if== | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:if|$condition as item()*, $then as item()*|item()*}}<br/>{{Func|util:if|$condition as item()*, $then as item()*, $else as item()*|item()*}}<br/> | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Alternative writing for the if/then/else expression: | ||
+ | * If the ''effective boolean value'' of {{Code|$condition}} is true, the {{Code|$then}} branch will be evaluated. | ||
+ | * Otherwise, {{Code|$else}} will be evaluated. If no third argument is supplied, an empty sequence will be returned. | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * <code>util:if(true(), 123, 456)</code> returns {{Code|123}}. | ||
+ | * <code>util:if(0, 'wrong!')</code> returns an empty sequence. | ||
+ | |} | ||
+ | |||
+ | ==util:or== | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:or|$items as item()*, $default as item()*|item()*}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns {{Code|$items}} if it is a non-empty sequence. Otherwise, returns {{Code|$default}}. Equivalent to the following expressions: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | if(exists($items)) then $items else $default, | ||
+ | (: Elvis operator :) | ||
+ | $items ?: $default | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * <code>util:or(123, 456)</code> returns {{Code|123}}. | ||
+ | * <code>util:or(1[. = 0], -1)</code> returns {{Code|-1}}. | ||
+ | |} | ||
+ | |||
+ | ==util:within== | ||
+ | |||
+ | {{Mark|Introduced with Version 9.5:}} | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:within|$sequence as item()*, $min as xs:integer|xs:boolean}}<br/>{{Func|util:within|$sequence as item()*, $min as xs:integer, $max as xs:integer|xs:boolean}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Checks if the specified {{Code|$sequence}} has at least {{Code|$min}} and, optionally, at most {{Code|$max}} items. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | let $count := count($sequence) | ||
+ | return $count >= $min and $count <= $max | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * <code>util:within(('a', 'b', 'c'), 2)</code> returns {{Code|true}}. | ||
+ | * <code>util:within((1 to 1000000000)[. < 10], 3, 6)</code> returns {{Code|true}}. | ||
+ | |} | ||
+ | |||
+ | =Positional Access= | ||
− | ==util:item | + | ==util:item== |
{| width='100%' | {| width='100%' | ||
|- | |- | ||
| width='120' | '''Signatures''' | | width='120' | '''Signatures''' | ||
− | |{{Func|util:item | + | |{{Func|util:item|$sequence as item()*, $position as xs:double|item()?}}<br/> |
|- | |- | ||
| '''Summary''' | | '''Summary''' | ||
− | |Returns the item from {{Code|$sequence}} at the specified {{Code|$position}}. Equivalent to < | + | |Returns the item from {{Code|$sequence}} at the specified {{Code|$position}}. Equivalent to: |
+ | <syntaxhighlight lang="xquery"> | ||
+ | $sequence[$position] | ||
+ | </syntaxhighlight> | ||
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
| | | | ||
− | * <code>util:item | + | * <code>util:item(reverse(1 to 5), 1)</code> returns <code>5</code>. |
− | * <code>util:item | + | * <code>util:item(('a','b'), 0)</code> returns an empty sequence. |
|} | |} | ||
− | ==util: | + | ==util:range== |
{| width='100%' | {| width='100%' | ||
|- | |- | ||
| width='120' | '''Signatures''' | | width='120' | '''Signatures''' | ||
− | |{{Func|util: | + | |{{Func|util:range|$sequence as item()*, $first as xs:double, $last as xs:double|item()*}}<br/> |
|- | |- | ||
| '''Summary''' | | '''Summary''' | ||
− | |Returns items from {{Code|$sequence}}, starting at position {{Code|$first}} and ending at {{Code|$last}}. Equivalent to < | + | |Returns items from {{Code|$sequence}}, starting at position {{Code|$first}} and ending at {{Code|$last}}. Equivalent to: |
+ | <syntaxhighlight lang="xquery"> | ||
+ | subsequence($sequence, $first, $last - $first + 1) | ||
+ | </syntaxhighlight> | ||
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
| | | | ||
− | * <code>util: | + | * <code>util:range(//item, 11, 20)</code> returns all path results from (if available) position 11 to 20. |
|} | |} | ||
− | ==util:last | + | ==util:last== |
{| width='100%' | {| width='100%' | ||
|- | |- | ||
| width='120' | '''Signatures''' | | width='120' | '''Signatures''' | ||
− | |{{Func|util:last | + | |{{Func|util:last|$sequence as item()*|item()?}}<br/> |
|- | |- | ||
| '''Summary''' | | '''Summary''' | ||
− | |Returns last item of a {{Code|$sequence}}. Equivalent to < | + | |Returns last item of a {{Code|$sequence}}. Equivalent to: |
+ | <syntaxhighlight lang="xquery"> | ||
+ | $sequence[last()] | ||
+ | </syntaxhighlight> | ||
|- | |- | ||
| '''Examples''' | | '''Examples''' | ||
| | | | ||
− | * <code>util:last | + | * <code>util:last(reverse(1 to 100))</code> returns <code>1</code>. |
|} | |} | ||
+ | |||
+ | ==util:init== | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:init|$sequence as item()*|item()*}}<br/> | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns all items of a {{Code|$sequence}} except for the last one. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | $sequence[position() < last()] | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * <code>util:init(1 to 4)</code> returns <code>1 2 3</code>. | ||
+ | |} | ||
+ | |||
+ | =Node Functions= | ||
+ | |||
+ | ==util:ddo== | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:ddo|$nodes as node()*|node()*}}<br/> | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns nodes in ''distinct document order'': duplicate nodes will be removed, and the remaining nodes will be returned in [https://www.w3.org/TR/xquery-31/#dt-document-order document order]. As results of path expressions are brought distinct document order before they are returned, the function is equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | $nodes/self::node() | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | ==util:root== | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:root|$nodes as node()*|document-node()*}}<br/> | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns the document nodes of the specified {{Code|$nodes}}. The path expression <code>/abc</code> is internally represented as <code>util:root(.)/abc</code. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | $nodes ! / | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | =Array and Map Functions= | ||
+ | |||
+ | ==util:array-members== | ||
+ | |||
+ | {{Mark|Introduced with Version 9.5.}} | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:array-members|$array as array(*)|array(*)*}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns each member of an {{Code|$array}} as a new array. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | for $a in 1 to array:size($array) | ||
+ | return [ $array($a) ] | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * Returns three elements with the member values as concatenated text node. | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | let $array := [ (), 2, (3, 4) ] | ||
+ | for $member in array:members($array) | ||
+ | return element numbers { $member } | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | ==util:array-values== | ||
+ | |||
+ | {{Mark|Introduced with Version 9.5.}} | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:array-values|$array as array(*)|item()*}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns all members of an {{Code|$array}} as a sequence. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | $array ? * | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * Returns the array members as two items: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | let $array := [ (), 2, [ 3, 4 ] ] | ||
+ | return array:values($array) | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | ==util:map-entries== | ||
+ | |||
+ | {{Mark|Introduced with Version 9.5.}} | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:map-entries|$map as map(*)|map(xs:string, item()*)*}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns each entry of a {{Code|$map}} as a new map, each with a {{Code|key}} and {{Code|value}} entry. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | map:for-each($map, function($key, $value) { | ||
+ | map { "key": $key, "value": $value } | ||
+ | }) | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * Returns three elements named by the key of the map, and with the entries as concatenated text node. | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | let $map := map { 'a': (), 'b': 2, 'c': [ 3, 4 ] } | ||
+ | for $entry in map:entries($map) | ||
+ | return element { $entry?key } { string-join($entry?value) } | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | ==util:map-values== | ||
+ | |||
+ | {{Mark|Introduced with Version 9.5.}} | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:map-values|$map as map(*)|item()*}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns all values of a {{Code|$map}} as a sequence. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | $map ? * | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * Returns the map values as two items: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | let $map := map { 'a': (), 'b': 2, 'c': [ 3, 4 ] } | ||
+ | return map:values($map) | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | =Helper Functions= | ||
==util:replicate== | ==util:replicate== | ||
+ | |||
+ | {{Mark|Updated with Version 9.5:}} Third argument added. | ||
{| width='100%' | {| width='100%' | ||
|- | |- | ||
| width='120' | '''Signatures''' | | width='120' | '''Signatures''' | ||
− | |{{Func|util:replicate|$ | + | |{{Func|util:replicate|$input as item()*, $count as xs:integer|item()*}}<br/>{{Func|util:replicate|$input as item()*, $count as xs:integer, $multiple as xs:boolean|item()*}} |
|- | |- | ||
| '''Summary''' | | '''Summary''' | ||
− | | | + | |Evaluates {{Code|$input}} and returns the result {{Code|$count}} times. Unless {{Code|$multiple}} is enabled, the input expression is only evaluated once. Equivalent expressions: |
+ | <syntaxhighlight lang="xquery"> | ||
+ | util:replicate($input, $count, true()), | ||
+ | (1 to $count) ! $input | ||
+ | </syntaxhighlight> | ||
|- | |- | ||
| '''Errors''' | | '''Errors''' | ||
Line 69: | Line 315: | ||
| | | | ||
* <code>util:replicate('A', 3)</code> returns <code>A A A</code>. | * <code>util:replicate('A', 3)</code> returns <code>A A A</code>. | ||
+ | * In the following query, a single new element node is constructed, and {{Code|true}} is returned: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | let $nodes := util:replicate(<node/>, 2) | ||
+ | return $nodes[1] is $nodes[2] | ||
+ | </syntaxhighlight> | ||
+ | * In this query, two nodes are constructed, and the result is {{Code|false}}: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | let $nodes := util:replicate(<node/>, 2, true()) | ||
+ | return $nodes[1] is $nodes[2] | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | ==util:intersperse== | ||
+ | |||
+ | {{Mark|Introduced with Version 9.5.}} | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:intersperse|$items as item()*, $separator as item()*|item()*}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Inserts the defined {{Code|$separator}} between the {{Code|$items}} of a sequence and returns the resulting sequence. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | head($items), for $item in tail($items) return ($separator, $item) | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | Inserts semicolon strings between the three input items: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | fn:intersperse((<_>1</_>, <_>2</_>, <_>3</_>), '; ') | ||
+ | </syntaxhighlight> | ||
+ | |} | ||
+ | |||
+ | ==util:duplicates== | ||
+ | |||
+ | {{Mark|Introduced with Version 9.5.}} | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:duplicates|$sequence as item()*|xs:anyAtomicType*}}<br/>{{Func|util:duplicates|$sequence as item()*, $collation as xs:string|xs:anyAtomicType*}} | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns duplicate values in a {{Code|$sequence}}. See [https://www.w3.org/TR/xpath-functions-31/#func-distinct-values fn:distinct-values] for the applied equality rules and the usage of the {{Code|$collation}} argument. | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * <code>util:duplicates((1, 2, 1, 1))</code> returns <code>1</code>. | ||
+ | |} | ||
+ | |||
+ | ==util:chars== | ||
+ | |||
+ | {| width='100%' | ||
+ | |- | ||
+ | | width='120' | '''Signatures''' | ||
+ | |{{Func|util:chars|$string as xs:string|xs:string*}}<br/> | ||
+ | |- | ||
+ | | '''Summary''' | ||
+ | |Returns all characters of a {{Code|$string}} as a sequence. Equivalent to: | ||
+ | <syntaxhighlight lang="xquery"> | ||
+ | for $cp in string-to-codepoints($string) | ||
+ | return codepoints-to-string($cp) | ||
+ | </syntaxhighlight> | ||
+ | |- | ||
+ | | '''Examples''' | ||
+ | | | ||
+ | * <code>util:chars('AB')</code> returns the two strings <code>A</code> and <code>B</code>. | ||
|} | |} | ||
Line 82: | Line 396: | ||
=Changelog= | =Changelog= | ||
+ | |||
+ | ;Version 9.5 | ||
+ | * Added: [[#util:intersperse|util:intersperse]], [[#util:within|util:within]], [[#util:duplicates|util:duplicates]], [[#util:array-members|util:array-members]], [[#util:array-values|util:array-values]], [[#util:map-entries|util:map-entries]], [[#util:map-values|util:map-values]] | ||
+ | * Updated: [[#util:replicate|util:replicate]]: Third argument added. | ||
+ | |||
+ | ;Version 9.4 | ||
+ | * Added: [[#util:root|util:root]] | ||
+ | |||
+ | ;Version 9.3 | ||
+ | * Added: [[#util:ddo|util:ddo]] | ||
+ | |||
+ | ;Version 9.2 | ||
+ | * Added: [[#util:chars|util:chars]], [[#util:init|util:init]] | ||
+ | * Updated: [[#util:item|util:item]], [[#util:last|util:last]], [[#util:range|util:range]] renamed (before: {{Code|util:item-at}}, {{Code|util:item-range}}, {{Code|util:last-from}}) | ||
+ | |||
+ | ;Version 9.1 | ||
+ | * Added: [[#util:if|util:if]], [[#util:or|util:or]] | ||
;Version 9.0 | ;Version 9.0 |
Revision as of 12:17, 25 February 2021
This XQuery Module contains various utility and helper functions.
For all listed functions, equivalent expressions exist in standard XQuery, but code may be better readable with function calls:
<syntaxhighlight lang="xquery"> (: standard XQuery :) let $result := if(exists($sequence)) then $sequence else ('default', 'values') return $result[last()]
(: XQuery with functions of this module :) $sequence => util:or(('default', 'values')) => util:last() </syntaxhighlight>
In addition, various query optimizations create calls to the utility functions.
Contents
Conventions
All functions and errors in this module and errors are assigned to the http://basex.org/modules/util
namespace, which is statically bound to the util
prefix.
Conditions
util:if
Signatures | util:if($condition as item()*, $then as item()*) as item()* util:if($condition as item()*, $then as item()*, $else as item()*) as item()* |
Summary | Alternative writing for the if/then/else expression:
|
Examples |
|
util:or
Signatures | util:or($items as item()*, $default as item()*) as item()*
|
Summary | Returns $items if it is a non-empty sequence. Otherwise, returns $default . Equivalent to the following expressions:
<syntaxhighlight lang="xquery"> if(exists($items)) then $items else $default, (: Elvis operator :) $items ?: $default </syntaxhighlight> |
Examples |
|
util:within
Signatures | util:within($sequence as item()*, $min as xs:integer) as xs:boolean util:within($sequence as item()*, $min as xs:integer, $max as xs:integer) as xs:boolean
|
Summary | Checks if the specified $sequence has at least $min and, optionally, at most $max items. Equivalent to:
<syntaxhighlight lang="xquery"> let $count := count($sequence) return $count >= $min and $count <= $max </syntaxhighlight> |
Examples |
|
Positional Access
util:item
Signatures | util:item($sequence as item()*, $position as xs:double) as item()? |
Summary | Returns the item from $sequence at the specified $position . Equivalent to:
<syntaxhighlight lang="xquery"> $sequence[$position] </syntaxhighlight> |
Examples |
|
util:range
Signatures | util:range($sequence as item()*, $first as xs:double, $last as xs:double) as item()* |
Summary | Returns items from $sequence , starting at position $first and ending at $last . Equivalent to:
<syntaxhighlight lang="xquery"> subsequence($sequence, $first, $last - $first + 1) </syntaxhighlight> |
Examples |
|
util:last
Signatures | util:last($sequence as item()*) as item()? |
Summary | Returns last item of a $sequence . Equivalent to:
<syntaxhighlight lang="xquery"> $sequence[last()] </syntaxhighlight> |
Examples |
|
util:init
Signatures | util:init($sequence as item()*) as item()* |
Summary | Returns all items of a $sequence except for the last one. Equivalent to:
<syntaxhighlight lang="xquery"> $sequence[position() < last()] </syntaxhighlight> |
Examples |
|
Node Functions
util:ddo
Signatures | util:ddo($nodes as node()*) as node()* |
Summary | Returns nodes in distinct document order: duplicate nodes will be removed, and the remaining nodes will be returned in document order. As results of path expressions are brought distinct document order before they are returned, the function is equivalent to:
<syntaxhighlight lang="xquery"> $nodes/self::node() </syntaxhighlight> |
util:root
Signatures | util:root($nodes as node()*) as document-node()* |
Summary | Returns the document nodes of the specified $nodes . The path expression /abc is internally represented as util:root(.)/abc</code. Equivalent to:
|
Array and Map Functions
util:array-members
Signatures | util:array-members($array as array(*)) as array(*)*
|
Summary | Returns each member of an $array as a new array. Equivalent to:
<syntaxhighlight lang="xquery"> for $a in 1 to array:size($array) return [ $array($a) ] </syntaxhighlight> |
Examples |
<syntaxhighlight lang="xquery"> let $array := [ (), 2, (3, 4) ] for $member in array:members($array) return element numbers { $member } </syntaxhighlight> |
util:array-values
Signatures | util:array-values($array as array(*)) as item()*
|
Summary | Returns all members of an $array as a sequence. Equivalent to:
<syntaxhighlight lang="xquery"> $array ? * </syntaxhighlight> |
Examples |
<syntaxhighlight lang="xquery"> let $array := [ (), 2, [ 3, 4 ] ] return array:values($array) </syntaxhighlight> |
util:map-entries
Signatures | util:map-entries($map as map(*)) as map(xs:string, item()*)*
|
Summary | Returns each entry of a $map as a new map, each with a key and value entry. Equivalent to:
<syntaxhighlight lang="xquery"> map:for-each($map, function($key, $value) { map { "key": $key, "value": $value } }) </syntaxhighlight> |
Examples |
<syntaxhighlight lang="xquery"> let $map := map { 'a': (), 'b': 2, 'c': [ 3, 4 ] } for $entry in map:entries($map) return element { $entry?key } { string-join($entry?value) } </syntaxhighlight> |
util:map-values
Signatures | util:map-values($map as map(*)) as item()*
|
Summary | Returns all values of a $map as a sequence. Equivalent to:
<syntaxhighlight lang="xquery"> $map ? * </syntaxhighlight> |
Examples |
<syntaxhighlight lang="xquery"> let $map := map { 'a': (), 'b': 2, 'c': [ 3, 4 ] } return map:values($map) </syntaxhighlight> |
Helper Functions
util:replicate
Template:Mark Third argument added.
Signatures | util:replicate($input as item()*, $count as xs:integer) as item()* util:replicate($input as item()*, $count as xs:integer, $multiple as xs:boolean) as item()*
|
Summary | Evaluates $input and returns the result $count times. Unless $multiple is enabled, the input expression is only evaluated once. Equivalent expressions:
<syntaxhighlight lang="xquery"> util:replicate($input, $count, true()), (1 to $count) ! $input </syntaxhighlight> |
Errors | negative : The specified number is negative.
|
Examples |
<syntaxhighlight lang="xquery"> let $nodes := util:replicate(<node/>, 2) return $nodes[1] is $nodes[2] </syntaxhighlight>
<syntaxhighlight lang="xquery"> let $nodes := util:replicate(<node/>, 2, true()) return $nodes[1] is $nodes[2] </syntaxhighlight> |
util:intersperse
Signatures | util:intersperse($items as item()*, $separator as item()*) as item()*
|
Summary | Inserts the defined $separator between the $items of a sequence and returns the resulting sequence. Equivalent to:
<syntaxhighlight lang="xquery"> head($items), for $item in tail($items) return ($separator, $item) </syntaxhighlight> |
Examples | Inserts semicolon strings between the three input items:
<syntaxhighlight lang="xquery"> fn:intersperse((<_>1</_>, <_>2</_>, <_>3</_>), '; ') </syntaxhighlight> |
util:duplicates
Signatures | util:duplicates($sequence as item()*) as xs:anyAtomicType* util:duplicates($sequence as item()*, $collation as xs:string) as xs:anyAtomicType*
|
Summary | Returns duplicate values in a $sequence . See fn:distinct-values for the applied equality rules and the usage of the $collation argument.
|
Examples |
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util:chars
Signatures | util:chars($string as xs:string) as xs:string* |
Summary | Returns all characters of a $string as a sequence. Equivalent to:
<syntaxhighlight lang="xquery"> for $cp in string-to-codepoints($string) return codepoints-to-string($cp) </syntaxhighlight> |
Examples |
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Errors
Code | Description |
---|---|
negative
|
The specified number is negative. |
Changelog
- Version 9.5
- Added: util:intersperse, util:within, util:duplicates, util:array-members, util:array-values, util:map-entries, util:map-values
- Updated: util:replicate: Third argument added.
- Version 9.4
- Added: util:root
- Version 9.3
- Added: util:ddo
- Version 9.2
- Added: util:chars, util:init
- Updated: util:item, util:last, util:range renamed (before:
util:item-at
,util:item-range
,util:last-from
)
- Version 9.1
- Version 9.0
- Added: util:replicate
The Module was introduced with Version 8.5.