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==Maps==
==Arrays==
===Atomization===
==Lookup Operator==
==Arrow Operator==
===Map Functions===The string constructors syntax uses two backticks and a square bracket for opening and closing a string:
===Array Functions===
The following array functions are now available: <code>array:size</code>, <code>array:append</code>, <code>array:subarray</code>, <code>array:remove</code>, <code>array:insert-before</code>, <code>array:head</code>, <code>array:tail</code>, <code>array:reverse</code>, <code>array:join</code>, <code>array:flatten</code>, <code>array:for-each</code>, <code>array:filter</code>, <code>array:fold-left</code>, <code>array:fold-right</code>, <code>array:for-each-pair</code>
===JSON Functions===
====fn:parse-json====
; Signatures* <codepre>fn:parse-json( $input json as xs:string) as item()?</code>* <code>fn:parse-json($input as xs:string, $options as map(*) := ()) as item()?</codepre>
====fn:json-docs=doc===
; Signatures* <codepre>fn:json-doc( $uri href as xs:string) as item()?</code>* <code>fn:json-doc($uri as xs:string, $options as map(*) := ()) as item()?</codepre>
{{Mark|Warning}}<pre>fn: BaseX has been using the {{Code|json}} output method for a while. With BaseX 8.0, the implementation of this method will be rewritten -to comply with the new standard serialization rules. We will do our best to keep the updated code backward-compatible.xml( $json as xs:string? $options as map(*) := ()) as document-node()?</pre>
===fn:sort===
; Signatures* <codepre>fn:sort( $input as item()*) , $collation as item()*</code>* <code>xs:string? := fn:sort($input as itemdefault-collation()*, $key as function(item()*) as xs:anyAtomicType*) := fn:data#1) as item()*</codepre>
===fn:contains-token===
; Signatures* <codepre>fn:contains-token( $input value as xs:string*, $token as string) as xs:boolean</code>* <code>fn:contains-token($input as xs:string*, $token as string, $collation as xs:string? := fn:default-collation()) as xs:boolean</codepre>
===fn:parse-ietf-date===
; Signature* <codepre>fn:parse-ietf-date( $input value as xs:string?) as xs:stringdateTime?</codepre>
===fn:tokenize===
===fn:trace===
Items of type <code>xs:hexBinary</code> Returns the default language used for formatting numbers and <code>xs:base64Binary</code> can now be compared against each otherdates. The following queries all yield BaseX always returns {{Code|trueen}}:.
A new [[Full<pre lang='xquery'>(: returns 0 (both strings are compared as equal) :)compare('a-Text#Case-Insensitive Collation|Case-Insensitive Collation]] was addedb', 'ab', which ignores the case of ASCII characters'http://www.w3.org/2013/collation/UCA?alternate=shifted')</pre>
The features of XQuery 3.1 ''Enclosed expression'' is the syntactical term for the expressions that are still subject to changespecified inside a function body, try/catch clauses, but we are planning to add node constructors and some other expressions. In the following enhancements in near futureexample expressions, its the empty sequence:
* New functions: <codepre lang='xquery'>fndeclare function local:collation-keyx() { () };try { () } catch * { () },element x { () },text { () }</codepre> With XQuery 3.1, the expression can be omitted. The following query is equivalent to the upper one: <code>fn:load-pre lang='xquery-module</code'>, <code>fndeclare function local:transform</code>x() { };try { } catch * { }, <code>fn:random-number-generatorelement x { }text { }</codepre>
[[Category:XQuery]]
Text replacement - "syntaxhighlight" to "pre"
This article is part of the [[XQuery|XQuery Portal]].It summarizes provides a summary of the new most important features of the [httphttps://www.w3.org/TR/xquery-31/ XQuery 3.1] Working Draftthat are already supported by BaseXRecommendation.
A ''map'' is a function that associates a set of keys with values, resulting in a collection of key/value pairs. Each key/value pair in a map is called an entry. A key is an arbitrary atomic value, and the associated value is an arbitrary sequence. Within a map, no two entries have the same key, when compared using the {{Code|eq}} operator. It is not necessary that all the keys should be mutually comparable (for example, they can include a mixture of integers and strings).
Maps can be constructed as follows:
<pre classlang="brush:'xquery"'>
map { }, (: empty map :)
map { 'key': true(), 1984: (<a/>, <b/>) }, (: map with two entries :)
</pre>
The function corresponding to the map has the signature {{Code|function($key as xs:anyAtomicType) as item()*}}. The expression {{Code|$map($key)}} returns the associated value; the function call {{Code|map:get($map, $key)}} is equivalent. For example, if {{Code|$books-by-isbn}} is a map whose keys are ISBNs and whose associated values are {{Code|book}} elements, then the expression {{Code|$books-by-isbn("0470192747")}} returns the {{Code|book}} element with the given ISBN. The fact that a map is a function item allows it to be passed as an argument to higher[[Higher-order functions Order Functions]] that expect a function item as one of their arguments. As an example, the following query uses the higher-order function {{Code|fn:map($f, $seq)}} to extract all bound values from a map:
<pre classlang="brush:'xquery"'>
let $map := map { 'foo': 42, 'bar': 'baz', 123: 456 }
return fn:for-each(map:keys($map), $map)
Because a map is a function item, functions that apply to functions also apply to maps. A map is an anonymous function, so {{Code|fn:function-name}} returns the empty sequence; {{Code|fn:function-arity}} always returns {{Code|1}}.
Like all other values, maps are immutable. For example, the <code>[[{{Function|Map Module#map:remove|map:remove]]</code> }} function creates a new map by removing an entry from an existing map, but the existing map is not changed by the operation. Like sequences, maps have no identity. It is meaningful to compare the contents of two maps, but there is no way of asking whether they are "the same map": two maps with the same content are indistinguishable.
Maps may be compared using the {{Code|fn:deep-equal}} function. The [[Map Module]] describes the available set of map functions.
An ''array'' is a function that associates a set of positions, represented as positive integer keys, with values. The first position in an array is associated with the integer {{Code|1}}. The values of an array are called its members. In the type hierarchy, array has a distinct type, which is derived from function. In BaseX, arrays (as well as sequences) are based on an efficient [https://en.wikipedia.org/wiki/Finger_tree Finger Tree] implementation.
Arrays can be constructed in two ways. With the square bracket notation, the comma serves as delimiter:
<pre classlang="brush:'xquery"'>
[], (: empty array :)
[ (1, 2) ], (: array with single member :)
With the {{Code|array}} keyword and curly brackets, the inner expression is evaluated as usual, and the resulting values will be the members of the array:
<pre classlang="brush:'xquery"'>
array { }, (: empty array; same as: array { () } :)
array { (1, 2) }, (: array with three two members; same as: array { 1, 2 } :)
array { 1 to 2, 3 } (: array with three members; same as: array { 1, 2, 3 } :)
</pre>
The function corresponding to the array has the signature {{Code|function($index as xs:integer) as item()*}}. The expression {{Code|$array($index)}} returns an addressed member of the array. The following query returns the five array members {{Code|48 49 50 51 52}} as result:
<pre classlang="brush:'xquery"'>
let $array := array { 48 to 52 }
for $i in 1 to array:size($array)
</pre>
Like all other values, arrays are immutable. For example, the <code>[[{{Function|Array Module#array:reverse|array:reverse]]</code> }} function creates a new array containing a re-ordering of the members of an existing array, but the existing array is not changed by the operation. Like sequences, arrays have no identity. It is meaningful to compare the contents of two arrays, but there is no way of asking whether they are "the same array": two arrays with the same content are indistinguishable.
If an array is ''atomized'', all of its members will be atomized. As a result, an atomized item may now result in more than one item. Some examples:
<pre classlang="brush:'xquery"'>
fn:data([1 to 2]) (: returns the sequence 1, 2 :)
[ 'a', 'b', 'c' ] = 'b' (: returns true :)
Atomization also applies to function arguments. The following query returns 5, because the array will be atomized to a sequence of 5 integers:
<pre classlang="brush:'xquery"'>
let $f := function($x as xs:integer*) { count($x) }
return $f([1 to 5])
However, the next query returns 1, because the array is already of the general type {{Code|item()}}, and no atomization will take place:
<pre classlang="brush:'xquery"'>
let $f := function($x as item()*) { count($x) }
return $f([1 to 5])
Arrays can be compared with the {{Code|fn:deep-equal}} function. The [[Array Module]] describes the available set of array functions.
The lookup operator provides some syntactic sugar to access values of maps or array members at a specified position. It is introduced by the question mark ({{Code|?}}) and followed by a specifier. The specifier can be:
# A wildcard {{Code|*}},
The following example demonstrates the four alternatives:
<pre classlang="brush:'xquery"'>
let $map := map { 'R': 'red', 'G': 'green', 'B': 'blue' }
return (
$map?* (: 1. returns all values; same as: map:keys($map) ! $map(.) :),
$map?R (: 2. returns the value associated with the key 'R'; same as: $map('R') :),
$map?('G','B') (: 43. returns the values associated with the key 'G' and 'B' :)
),
return (
$array?* (: 1. returns all values; same as: (1 to array:size($array)) ! $array(.) :),
$array?1 (: 32. returns the first value; same as: $array(21) :), $array?(2 to 3) (: 43. returns the second and third values ; same as: (1 to 2 and 3 ) ! $array(.) :)
)
</pre>
The lookup operator can also be used without left operand. In this case, the context item will be used as input. This query returns {{Code|Akureyri}}:
<pre classlang="brush:'xquery"'>for let $map in maps := (
map { 'name': 'Guðrún', 'city': 'Reykjavík' },
map { 'name': 'Hildur', 'city': 'Akureyri' }
)
return $mapmaps[?name = 'Hildur'] ?city
</pre>
The arrow operator applies <code>=></code> provides a function convenient alternative syntax for passing on functions to a value. The value is used expression that precedes the operator will be supplied as the first argument to of the function. It is introduced with the characters <code>=></code>, and it is followed by that follows the function to be calledarrow. If <code>$v</code> is a value and <code>f()</code> is a function, then <code>$v=>f()</code> is equivalent to <code>f($v)</code>, and <code>$v=>f($j)</code> is equivalent to <code>f($v, $j)</code>. This is further illustrated by an example:
<pre classlang="brush:'xquery"'>
(: Returns 3 :)
count(('A', 'B', 'C')),
The syntax makes nested function calls more readable, as it is easy to see if parentheses are balanced.
==Functions=String Constructor=
The following functions of the string constructor has been inspired by [httphttps://wwwen.w3wikipedia.org/TRwiki/xpath-functions-31/ XQuery 3.1 Functions Here_document here document] literals of the Unix shell and Operators] Working Draft have been addedscript languages. Please It allows you to generate strings that contain various characters that would otherwise be aware that the functions are still subject to change:interpreted as XQuery delimiters.
<pre lang='xquery'>(: Returns "This is a 'new' & 'flexible' syntax." :)``["This is a 'new' & 'flexible' syntax."]``</pre> XQuery expressions can be embedded via backticks and a curly bracket. The evaluated results will be separated with spaces, and all strings will eventually be concatenated: <pre lang='xquery'>(: Returns »Count 1 2 3, and I will be there.« :)let $c := 1 to 3return ``[»Count `{ $c }`, and I will be there.«]``</pre> =Serialization= Two [[Serialization]] methods have been added to the [https://www.w3.org/TR/xslt-xquery-serialization-31 Serialization spec]: ==Adaptive Serialization== The {{Code|adaptive}} serialization provides an intuitive textual representation for all XDM types, including maps and arrays, functions, attributes, and namespaces. All items will be separated by the value of the {{Code|item-separator}} parameter, which by default is a newline character. It is utilized by the functions {{Function|Profiling|prof:dump}} and <code>[https://www.w3.org/TR/xpath-functions-31/#func-trace fn:trace]</code>. Example: <pre lang='xquery'>declare option output:method 'adaptive';<element id='id0'/>/@id,xs:token("abc"),map { 'key': 'value' },true#0</pre> Result: <pre lang="xml">id="id0"xs:token("abc"),map { "key": "value"}fn:true#0</pre> ==JSON Serialization== The new {{Code|json}} serialization output method can be used to serialize XQuery maps, arrays, atomic values and empty sequences as JSON. The {{Code|json}} output method has been introduced in BaseX before it was added to the official specification. It complies with the standard serialization rules and, at the same time, preserves the existing semantics: * If an XML node of type {{Code|element(json)}} is found, it will be serialized following the serialization rules of the [[JSON Module]].* Any other node or atomic value, map, array, or empty sequence will be serialized according to the [https://www.w3.org/TR/xslt-xquery-serialization-31/#json-output rules in the specification]. The following two queries will both return the JSON snippet <code>{ "key": "value" }</code>: <pre lang='xquery'>declare option output:method 'json';map { "key": "value" }</pre> <pre lang='xquery'>declare option output:method 'json';<json type='object'> <key>value</key></json></pre> =Functions= The following functions have been added in the [https://www.w3.org/TR/xpath-functions are now available-31/ XQuery 3.1 Functions and Operators] Specification: ==Map Functions==
<code>map:merge</code>, <code>map:size</code>, <code>map:keys</code>, <code>map:contains</code>, <code>map:get</code>, <code>map:entry</code>, <code>map:put</code>, <code>map:remove</code>, <code>map:for-each</code>
Please check out the [[Map Module]] for more details.
Please check out the [[Array Module]] for more details.
With XQuery now provides 3.1, native support for JSON objectswas added. Objects Strings and resources can be parsed to XQuery items and , as [[#JSON Serialization|shown above]], serialized back to their original form.
Parses the supplied string as JSON text and returns its item representation. The result may be a map, an array, a string, a double, a boolean, or an empty sequence. The allowed options are further specified can be looked up in the [httphttps://www.w3.org/TR/xpath-functions-31/#func-parse-json specification].
<pre classlang="brush:'xquery"'>map:serialize(parse-json('{ "name": "john" }')) (: yields { "name": "json" } :),parse-json('[ 1, 2, 4, 8, 16]')?* (: yields the integer sequence [ 1, 2, 4, 8, 16 ] :),
</pre>
Retrieves the text from the specified URI, parses the supplied string as JSON text and returns its item representation (see [[#fn:parse-json{{Function||fn:parse-json]] }} for more details).
<pre classlang="brush:'xquery"'>
json-doc("http://ip.jsontest.com/")('ip') (: returns your IP address :)
</pre>
====Serialization=fn:json-to-xml===
Converts a JSON string to an XML node representation. The allowed options can be looked up in the [https://www.w3.org/TR/xpath-functions-31/#func-json-to-xm specification]. <pre classlang="brush:'xquery"'>json-to-xml(: will return '{ "keymessage": "valueworld" } ') (: result:<map xmlns="http://www.w3.org/2005/xpath-functions"> <string key="message">world</string></map> :)declare option output</pre> ===fn:xml-to-json=== <pre>fn:method 'xml-to-json';( $node as xs:string? $options as map (*) := ()) as xs:string?</pre> Converts an XML node, whose format conforms to the results created by {{ Function||fn:json-to-xml}}, to a JSON string representation. The allowed options can be looked up in the [https://www.w3.org/TR/xpath-functions-31/#func-xml-to-json specification]. <pre lang='xquery'>(: returns "keyJSON": )xml-to-json(<string xmlns="valuehttp://www.w3.org/2005/xpath-functions" }>JSON</string>)
</pre>
Returns a new sequence with sorted {{Code|$input}} items, using an optional {{Code|$collation}}. If a sort {{Code|$key}} function is givensupplied, it will be applied on all items. The items of the resulting values will be sorted using the semantics of the {{Code|lt}} expression.
<pre classlang="brush:'xquery"'>sort(reverse(1 to 3)) (: yields 1, 2, 3 :),reverse(sort(1 to 3)) (: returns the sorted order in descending order :),sort((3, -2, 1), (), abs#1) (: yields 1, -2, 3 :),sort((1,2,3), (), function($x) { -$x }) (: yields 3, 2, 1 :),sort((1, 'a')) (: yields an error, as strings and integers cannot be compared :)
</pre>
The supplied strings will be tokenized at whitespace boundaries. The function returns {{Code|true}} if one of the strings equals the supplied token, possibly under the rules of a supplied collation:
<pre classlang="brush:'xquery"'>
contains-token(('a', 'b c', 'd'), 'c') (: yields true :)
<xml class='one two'/>/contains-token(@class, 'one') (: yields true :)
</pre>
Parses a string in the IETF format (which is widely used on the Internet) and returns a {{Code|xs:dateTime}} item:
<pre classlang="brush:'xquery"'>
fn:parse-ietf-date('28-Feb-1984 07:07:07')" (: yields 1984-02-28T07:07:07Z :),
fn:parse-ietf-date('Wed, 01 Jun 2001 23:45:54 +02:00')" (: yields 2001-06-01T23:45:54+02:00 :)
</pre>
==fn:apply== <pre>fn:apply( $function as function(*), $arguments as array(*)) as item()*</pre> The supplied {{Code|$function}} is invoked with the specified {{Code|$arguments}}. The arity of the function must be the same as the size of the array. Example: <pre lang='xquery'>fn:apply(concat#5, array { 1 to 5 }) (: 12345 :)fn:apply(function($a) { sum($a) }, [ 1 to 5 ]) (: 15 :)fn:apply(count#1, [ 1,2 ]) (: error. the array has two members :)</pre> ==fn:random-number-generator== <pre>fn:random-number-generator( $seed as xs:anyAtomicType? := ()) as map(xs:string, item())</pre> Creates a random number generator, using an optional seed. The returned map contains three entries: * {{Code|number}} is a random double between 0 and 1* {{Code|next}} is a function that returns another random number generator* {{Code|permute}} is a function that returns a random permutation of its argument The returned random generator is ''deterministic'': If the function is called twice with the same arguments and in the same execution scope, it will always return the same result. Example: <pre lang='xquery'>let $rng := fn:random-number-generator()let $number := $rng('number') (: returns a random number :)let $next-rng := $rng('next')() (: returns a new generator :)let $next-number := $next-rng('number') (: returns another random number :)let $permutation := $rng('permute')(1 to 5) (: returns a random permutation of (1,2,3,4,5) :)return ($number, $next-number, $permutation)</pre> ==fn:format-number===
The function has been extended to support scientific notation:
<pre classlang="brush:'xquery"'>
format-number(1984.42, '00.0e0') (: yields 19.8e2 :)
</pre>
If no separator is specified as second argument, a string will be tokenized at whitespace boundaries:
<pre classlang="brush:'xquery"'>
fn:tokenize(" a b c d") (: yields "a", "b", "c", "d" :)
</pre>
The second argument can now be omitted:
<pre classlang="brush:'xquery"'>
fn:trace(<xml/>, "Node: ")/node() (: yields the debugging output "Node: <xml/>" :),
fn:trace(<xml/>)/node() (: returns the debugging output "<xml/>" :)
</pre>
==Binary Datafn:string-join== The type of the first argument is now <code>xs:anyAtomicType*</code>, and all items will be implicitly cast to strings: <pre lang='xquery'>fn:string-join(1 to 3) (: yields the string "123" :)</pre> ==fn:default-language==
==Appendix== The three functions <code>fn:transform</code>, <code>fn:load-xquery-module</code> and <code>fn:collation-key</code> may be added in a future version of BaseX as their implementation might require the use of additional external libraries. =Binary Data= Items of type <code>xs:hexBinary</code> and <code>xs:base64Binary</code> can be compared against each other. The following queries all yield {{Code|true}}: <pre classlang="brush:'xquery"'>
xs:hexBinary('') < xs:hexBinary('bb'),
xs:hexBinary('aa') < xs:hexBinary('bb'),
</pre>
=Collations=Collations XQuery 3.1 provides a default collation, which allows for a case-insensitive comparison of ASCII characters (<code>A-Z</code> = <code>a-z</code>). This query returns <code>true</code>: <pre lang='xquery'>declare default collation 'http://www.w3.org/2005/xpath-functions/collation/html-ascii-case-insensitive';'HTML' ='html'</pre> If the [http://site.icu-project.org/download ICU Library] is downloaded and added to the classpath, the full [https://www.w3.org/TR/xpath-functions-31/#uca-collations Unicode Collation Algorithm] features become available in BaseX:
==Pending Features=Enclosed Expressions=
=Changelog=
;Version 8.6
* Updated: Collation argument was inserted between first and second argument.
;Version 8.4
* Added: [[#String Constructors|String Constructors]], {{Code|fn:default-language}}, [[#Enclosed Expressions|Enclosed Expressions]]
* Updated: [[#Adaptive Serialization|Adaptive Serialization]], {{Code|fn:string-join}}
;Version 8.2
* Added: {{Code|fn:json-to-xml}}, {{Code|fn:xml-to-json}}.
;Version 8.1
* Updated: arrays are now based on a [https://en.wikipedia.org/wiki/Finger_tree Finger Tree] implementation.
Introduced with Version 8.0.
