Compare XPath functions in W3C spec vs. eXist 3.4.0

exist-xpath-functions.xq

xquery version "3.1";

element modules { 
    util:registered-modules()[starts-with(., 'http://www.w3')] ! 
        element module {
            element namespace-uri {.},
            util:registered-functions(.) ! 
                element function {.}
        } 
}

exist-xpath-functions_results.xml

<modules>
    <module>
        <namespace-uri>http://www.w3.org/2005/xpath-functions/array</namespace-uri>
        <function>array:append</function>
        <function>array:filter</function>
        <function>array:flatten</function>
        <function>array:fold-left</function>
        <function>array:fold-right</function>
        <function>array:for-each</function>
        <function>array:for-each-pair</function>
        <function>array:get</function>
        <function>array:head</function>
        <function>array:insert-before</function>
        <function>array:join</function>
        <function>array:remove</function>
        <function>array:reverse</function>
        <function>array:size</function>
        <function>array:subarray</function>
        <function>array:tail</function>
    </module>
    <module>
        <namespace-uri>http://www.w3.org/2005/xpath-functions/math</namespace-uri>
        <function>acos</function>
        <function>asin</function>
        <function>atan</function>
        <function>atan2</function>
        <function>cos</function>
        <function>exp</function>
        <function>exp10</function>
        <function>log</function>
        <function>log10</function>
        <function>pi</function>
        <function>pow</function>
        <function>sin</function>
        <function>sqrt</function>
        <function>tan</function>
    </module>
    <module>
        <namespace-uri>http://www.w3.org/2005/xpath-functions</namespace-uri>
        <function>QName</function>
        <function>abs</function>
        <function>adjust-date-to-timezone</function>
        <function>adjust-dateTime-to-timezone</function>
        <function>adjust-time-to-timezone</function>
        <function>analyze-string</function>
        <function>apply</function>
        <function>available-environment-variables</function>
        <function>avg</function>
        <function>base-uri</function>
        <function>boolean</function>
        <function>ceiling</function>
        <function>codepoint-equal</function>
        <function>codepoints-to-string</function>
        <function>collection</function>
        <function>compare</function>
        <function>concat</function>
        <function>contains</function>
        <function>count</function>
        <function>current-date</function>
        <function>current-dateTime</function>
        <function>current-time</function>
        <function>data</function>
        <function>dateTime</function>
        <function>day-from-date</function>
        <function>day-from-dateTime</function>
        <function>days-from-duration</function>
        <function>deep-equal</function>
        <function>default-collation</function>
        <function>distinct-values</function>
        <function>doc</function>
        <function>doc-available</function>
        <function>document-uri</function>
        <function>empty</function>
        <function>encode-for-uri</function>
        <function>ends-with</function>
        <function>environment-variable</function>
        <function>equals</function>
        <function>error</function>
        <function>escape-html-uri</function>
        <function>escape-uri</function>
        <function>exactly-one</function>
        <function>exists</function>
        <function>false</function>
        <function>filter</function>
        <function>floor</function>
        <function>fold-left</function>
        <function>fold-right</function>
        <function>for-each</function>
        <function>for-each-pair</function>
        <function>format-date</function>
        <function>format-dateTime</function>
        <function>format-number</function>
        <function>format-time</function>
        <function>function-arity</function>
        <function>function-lookup</function>
        <function>function-name</function>
        <function>generate-id</function>
        <function>has-children</function>
        <function>head</function>
        <function>hours-from-dateTime</function>
        <function>hours-from-duration</function>
        <function>hours-from-time</function>
        <function>id</function>
        <function>idref</function>
        <function>implicit-timezone</function>
        <function>in-scope-prefixes</function>
        <function>index-of</function>
        <function>innermost</function>
        <function>insert-before</function>
        <function>iri-to-uri</function>
        <function>json-doc</function>
        <function>lang</function>
        <function>last</function>
        <function>load-xquery-module</function>
        <function>local-name</function>
        <function>local-name-from-QName</function>
        <function>lower-case</function>
        <function>map</function>
        <function>map-pairs</function>
        <function>matches</function>
        <function>max</function>
        <function>min</function>
        <function>minutes-from-dateTime</function>
        <function>minutes-from-duration</function>
        <function>minutes-from-time</function>
        <function>month-from-date</function>
        <function>month-from-dateTime</function>
        <function>months-from-duration</function>
        <function>name</function>
        <function>namespace-uri</function>
        <function>namespace-uri-for-prefix</function>
        <function>namespace-uri-from-QName</function>
        <function>nilled</function>
        <function>node-name</function>
        <function>normalize-space</function>
        <function>normalize-unicode</function>
        <function>not</function>
        <function>number</function>
        <function>one-or-more</function>
        <function>outermost</function>
        <function>parse-json</function>
        <function>parse-xml</function>
        <function>parse-xml-fragment</function>
        <function>position</function>
        <function>prefix-from-QName</function>
        <function>remove</function>
        <function>replace</function>
        <function>resolve-QName</function>
        <function>resolve-uri</function>
        <function>reverse</function>
        <function>root</function>
        <function>round</function>
        <function>round-half-to-even</function>
        <function>seconds-from-dateTime</function>
        <function>seconds-from-duration</function>
        <function>seconds-from-time</function>
        <function>serialize</function>
        <function>sort</function>
        <function>starts-with</function>
        <function>static-base-uri</function>
        <function>string</function>
        <function>string-join</function>
        <function>string-length</function>
        <function>string-to-codepoints</function>
        <function>subsequence</function>
        <function>substring</function>
        <function>substring-after</function>
        <function>substring-before</function>
        <function>sum</function>
        <function>tail</function>
        <function>timezone-from-date</function>
        <function>timezone-from-dateTime</function>
        <function>timezone-from-time</function>
        <function>tokenize</function>
        <function>trace</function>
        <function>translate</function>
        <function>true</function>
        <function>unordered</function>
        <function>upper-case</function>
        <function>year-from-date</function>
        <function>year-from-dateTime</function>
        <function>years-from-duration</function>
        <function>zero-or-one</function>
    </module>
    <module>
        <namespace-uri>http://www.w3.org/2005/xpath-functions/map</namespace-uri>
        <function>map:contains</function>
        <function>map:entry</function>
        <function>map:for-each</function>
        <function>map:for-each-entry</function>
        <function>map:get</function>
        <function>map:keys</function>
        <function>map:merge</function>
        <function>map:new</function>
        <function>map:put</function>
        <function>map:remove</function>
        <function>map:size</function>
    </module>
</modules>

w3c-xpath-spec-functions.xq

xquery version "3.1";

declare namespace fos="http://www.w3.org/xpath-functions/spec/namespace";

element modules {
    let $all-functions := hc:send-request(<hc:request href='https://www.w3.org/TR/2017/REC-xpath-functions-31-20170321/function-catalog.xml' method='get'/>)[2]//fos:function[@prefix ne 'op']
    for $functions in $all-functions
    group by $namespace-prefix := $functions/@prefix
    return
        element module {
            element namespace-prefix { $namespace-prefix },
            for $function in $functions
            order by $function/@name
            return
                element function { $function/@name/string() }
        }
}

w3c-xpath-spec-functions_results.xml

<modules>
    <module>
        <namespace-prefix prefix="array"/>
        <function>append</function>
        <function>filter</function>
        <function>flatten</function>
        <function>fold-left</function>
        <function>fold-right</function>
        <function>for-each</function>
        <function>for-each-pair</function>
        <function>get</function>
        <function>head</function>
        <function>insert-before</function>
        <function>join</function>
        <function>put</function>
        <function>remove</function>
        <function>reverse</function>
        <function>size</function>
        <function>sort</function>
        <function>subarray</function>
        <function>tail</function>
    </module>
    <module>
        <namespace-prefix prefix="math"/>
        <function>acos</function>
        <function>asin</function>
        <function>atan</function>
        <function>atan2</function>
        <function>cos</function>
        <function>exp</function>
        <function>exp10</function>
        <function>log</function>
        <function>log10</function>
        <function>pi</function>
        <function>pow</function>
        <function>sin</function>
        <function>sqrt</function>
        <function>tan</function>
    </module>
    <module>
        <namespace-prefix prefix="fn"/>
        <function>QName</function>
        <function>abs</function>
        <function>adjust-date-to-timezone</function>
        <function>adjust-dateTime-to-timezone</function>
        <function>adjust-time-to-timezone</function>
        <function>analyze-string</function>
        <function>apply</function>
        <function>available-environment-variables</function>
        <function>avg</function>
        <function>base-uri</function>
        <function>boolean</function>
        <function>ceiling</function>
        <function>codepoint-equal</function>
        <function>codepoints-to-string</function>
        <function>collation-key</function>
        <function>collection</function>
        <function>compare</function>
        <function>concat</function>
        <function>contains</function>
        <function>contains-token</function>
        <function>count</function>
        <function>current-date</function>
        <function>current-dateTime</function>
        <function>current-time</function>
        <function>data</function>
        <function>dateTime</function>
        <function>day-from-date</function>
        <function>day-from-dateTime</function>
        <function>days-from-duration</function>
        <function>deep-equal</function>
        <function>default-collation</function>
        <function>default-language</function>
        <function>distinct-values</function>
        <function>doc</function>
        <function>doc-available</function>
        <function>document-uri</function>
        <function>element-with-id</function>
        <function>empty</function>
        <function>encode-for-uri</function>
        <function>ends-with</function>
        <function>environment-variable</function>
        <function>error</function>
        <function>escape-html-uri</function>
        <function>exactly-one</function>
        <function>exists</function>
        <function>false</function>
        <function>filter</function>
        <function>floor</function>
        <function>fold-left</function>
        <function>fold-right</function>
        <function>for-each</function>
        <function>for-each-pair</function>
        <function>format-date</function>
        <function>format-dateTime</function>
        <function>format-integer</function>
        <function>format-number</function>
        <function>format-time</function>
        <function>function-arity</function>
        <function>function-lookup</function>
        <function>function-name</function>
        <function>generate-id</function>
        <function>has-children</function>
        <function>head</function>
        <function>hours-from-dateTime</function>
        <function>hours-from-duration</function>
        <function>hours-from-time</function>
        <function>id</function>
        <function>idref</function>
        <function>implicit-timezone</function>
        <function>in-scope-prefixes</function>
        <function>index-of</function>
        <function>innermost</function>
        <function>insert-before</function>
        <function>iri-to-uri</function>
        <function>json-doc</function>
        <function>json-to-xml</function>
        <function>lang</function>
        <function>last</function>
        <function>load-xquery-module</function>
        <function>local-name</function>
        <function>local-name-from-QName</function>
        <function>lower-case</function>
        <function>matches</function>
        <function>max</function>
        <function>min</function>
        <function>minutes-from-dateTime</function>
        <function>minutes-from-duration</function>
        <function>minutes-from-time</function>
        <function>month-from-date</function>
        <function>month-from-dateTime</function>
        <function>months-from-duration</function>
        <function>name</function>
        <function>namespace-uri</function>
        <function>namespace-uri-for-prefix</function>
        <function>namespace-uri-from-QName</function>
        <function>nilled</function>
        <function>node-name</function>
        <function>normalize-space</function>
        <function>normalize-unicode</function>
        <function>not</function>
        <function>number</function>
        <function>one-or-more</function>
        <function>outermost</function>
        <function>parse-ietf-date</function>
        <function>parse-json</function>
        <function>parse-xml</function>
        <function>parse-xml-fragment</function>
        <function>path</function>
        <function>position</function>
        <function>prefix-from-QName</function>
        <function>random-number-generator</function>
        <function>remove</function>
        <function>replace</function>
        <function>resolve-QName</function>
        <function>resolve-uri</function>
        <function>reverse</function>
        <function>root</function>
        <function>round</function>
        <function>round-half-to-even</function>
        <function>seconds-from-dateTime</function>
        <function>seconds-from-duration</function>
        <function>seconds-from-time</function>
        <function>serialize</function>
        <function>sort</function>
        <function>starts-with</function>
        <function>static-base-uri</function>
        <function>string</function>
        <function>string-join</function>
        <function>string-length</function>
        <function>string-to-codepoints</function>
        <function>subsequence</function>
        <function>substring</function>
        <function>substring-after</function>
        <function>substring-before</function>
        <function>sum</function>
        <function>tail</function>
        <function>timezone-from-date</function>
        <function>timezone-from-dateTime</function>
        <function>timezone-from-time</function>
        <function>tokenize</function>
        <function>trace</function>
        <function>transform</function>
        <function>translate</function>
        <function>true</function>
        <function>unordered</function>
        <function>unparsed-text</function>
        <function>unparsed-text-available</function>
        <function>unparsed-text-lines</function>
        <function>upper-case</function>
        <function>uri-collection</function>
        <function>xml-to-json</function>
        <function>year-from-date</function>
        <function>year-from-dateTime</function>
        <function>years-from-duration</function>
        <function>zero-or-one</function>
    </module>
    <module>
        <namespace-prefix prefix="map"/>
        <function>contains</function>
        <function>entry</function>
        <function>find</function>
        <function>for-each</function>
        <function>get</function>
        <function>keys</function>
        <function>merge</function>
        <function>put</function>
        <function>remove</function>
        <function>size</function>
    </module>
</modules>

As of eXist 3.4.0:

Unique to W3C list:

• array:put
• array:sort
• fn:collation-key
• fn:contains-token
• fn:default-language
• fn:element-with-id
• fn:format-integer
• fn:json-to-xml
• fn:outermost
• fn:parse-ietf-date
• fn:path
• fn:random-number-generator
• fn:transform
• fn:unparsed-text
• fn:unparsed-text-available
• fn:unparsed-text-lines
• fn:uri-collection
• fn:xml-to-json
• map:find

Unique to eXist

• fn:equals
• fn:escape-uri
• fn:map
• fn:map-pairs
• map:for-each-entry
• map:new