[xsl] XSLT 4: map serialization

["Graydon graydon@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

So if I have a sequence of maps, such as one gets from using collection() with the metadata flag set in Saxon, and I want to serialize the result just to see what is in there, I'd like to be able to use:

<xsl:sequence select="$fileArchive ! map:for-each(.,function($k,$v){element{$k}{$v}})" />

This isn't allowed, because map:for-each() takes an XPath function, rather than an XQuery function, so it hasn't got access to element constructors.

<xsl:for-each select="$fileArchive">
  <xsl:variable as="map(*)" name="currentEntry" select="." />
  <entry>
    <xsl:for-each select="map:keys($currentEntry)[not(. eq 'fetch')]">
      <xsl:element name="{.}">
        <xsl:sequence select="$currentEntry(.)" />
      </xsl:element>
    </xsl:for-each>
  </entry>
</xsl:for-each>

works fine, but I can't help but feel that it lacks elegance of
expression compared to the map:for-each() construction.

Allowing XQuery anonymous functions would be a large change, but at least in the map serialization case[1] I have trouble thinking of a better option.  XQuery functions are at least already well-defined.

[1] I cannot tell you how much I want to be able to pass parameters to a functioned returned from a map of function items and have that function return elements for applying-a-style purposes, e.g.

<xsl:sequence select="$stylesMap($styleTypeName)($stylePropertiesMap($styleName))" />

-- 
Graydon Saunders  | graydonish@xxxxxxxxx
^fs oferiode, pisses swa mfg.
-- Deor  ("That passed, so may this.")