retrieve all XPaths to nodes within an element

readme.md

what is the shortest XQuery that returns all XPaths in the current context

1. //(node()|@*)!path()
2. //node()!(.,@*)!path(.)

• xqueryfiddle

Special thanks to Reece H. Dunn for pointing me towards fn:path

Working Demos (previous versions)

• xqueryfiddle
• fontoxpath playground

current-winner.xq

(: thanks to Reece H. Dunn for hinting at the fn:path function :)
//node()!(.,@*)!path()

minified-fonto.xq

//node()!(.,@*)!string-join(tail((ancestor::*,.))!(let$n:=name(.)let$t:=typeswitch(.)case attribute()
return -2 caseelement() return -1 casecomment() return 1 casetext() return 2 default return 3 return
if($t>0)then let$e:=(["comment",preceding-sibling::comment()],["text",preceding-sibling::text()],["node",1])[$t]return$e?1||"()["||count($e?2)+1||"]"else
[$n||"["||count(preceding-sibling::*[name(.)=$n])+1||"]","@"||name(.)](-$t)),"/")!concat("/",.)

minified-saxon.xq

//node()!(.,@*)!string-join(tail((ancestor::*,.))!(let$n:=name(.)let$t:=typeswitch(.)case
attribute()return(-2)case element()return(-1)case comment()return(1)case text()return(2)default return(3)return if($t>0)then
let$e:=(["comment",preceding-sibling::comment()],["text",preceding-sibling::text()],["node",1])[$t]return$e?1||"()["||count($e?2)+1||"]"else
[$n||"["||count(preceding-sibling::*[name(.)=$n])+1||"]","@"||name(.)](-$t)),"/")!concat("/",.)

xpaths.xq

xquery version "3.1";

declare namespace xpaths="http://line-o.de/ns/xpaths";

declare namespace tei="http://www.tei-c.org/ns/1.0";

(:~
 : A pure XQuery implementation of fn:path
 :)
declare function xpaths:path ($node as node()) as xs:string {
    (
        ($node/ancestor::*, $node)
        ! (
            let $t :=
                typeswitch(.)
                case attribute() return -2
                case element() return -1
                case comment() return 1
                case text() return 2
                default return 3

            return
                if ($t > 0)
                then
                    let $e := (
                       ["comment", preceding-sibling::comment()],
                       ["text", preceding-sibling::text()],
                       ["node", 1]
                    )[$t]
                    return ``[`{$e?1}`()[`{count($e?2)+1}`]]``
                else
                    let $n := name(.)
                    let $qn := xs:QName(name(.))
                    let $q := "Q{" || namespace-uri-from-QName($qn) || "}" || local-name-from-QName($qn)
                    let $i := -$t (: see https://github.com/eXist-db/exist/issues/3892 :)
                    return (
                        ``[`{$q}`[`{count(preceding-sibling::*[name(.)=$n])+1}`]]``, 
                        "@" || $q )[$i]
        ) => string-join("/")
    )
    ! concat("/", .)
};


let $xml := document {
    <xml>
      <a><![CDATA[<b/>]]></a>
      <c><d>N<!-- no comment --><e/></d></c>
      <c xml:id="s123" a="1"><d>E<e/></d></c>
      <c><d>M<e/></d></c>
      <c><d>O<e/></d></c>
      <tei:TEI />
    </xml>
}

let $test :=
    function ($xpath as xs:string) as item()* {
        util:eval(concat("$xml", $xpath))
    }

return
    $root//node()
    ! (., @*)
    ! xpaths:path(.)
    ! $test(.)