Re: Subtle (or not?) Map Processing Bug in XQuery

Christian and Jean-Paul,



I hadnbt thought about map:for-each() (not sure I even realized it was an
option).



Ibll have to think about that more.



Map:for-each() B feels very familiar to my JavaScript brain (which it pains me
to admit I even have but there it is).



Ibll check out Joebs book...



Cheers,



E.



--

Eliot Kimber

http://contrext.com







From: "Christian GrC<n christian.gruen@xxxxxxxxx"
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Reply-To: <xsl-list@xxxxxxxxxxxxxxxxxxxxxx>
Date: Friday, January 7, 2022 at 11:21 AM
To: xsl-list <xsl-list@xxxxxxxxxxxxxxxxxxxxxx>
Subject: Re:  Subtle (or not?) Map Processing Bug in XQuery



Hi Eliot,



Ibm also wondering if therebs any general source of XQuery coding patterns
for working with maps in non-trivial ways? I havenbt run across one but I
havenbt looked too hard yet.



You could use map:remove, either with map:keysb&



let $orphanMap := map:remove($imageMap,

  map:keys($imageMap)[not(local:notReferenced($imageMap(.)('keyname')))]

)



b&or in combination with map:for-each:



let $orphanMap := map:remove($imageMap,

  map:for-each($imageMap, function($k, $v) {

    if(local:notReferenced($v('keyname'))) then () else $k

  })

)



XQuery 4.0 will probably include a map:filter function [1] and,

possibly, additional functions for iterating over the entries of a map

[2].



Hope this helps,

Christian



[1]
https://qt4cg.org/branch/master/xpath-functions-40/Overview.html#func-map-fil
ter

[2] https://github.com/qt4cg/qtspecs/issues/29