Re: return type of a function returning namespaces?

Use as="namespace-node()*" (at least in XPath 3.1, I haven't checked exactly
when it was introduced).

Michael Kay
Saxonica

> On 9 Jun 2022, at 04:31, Graydon graydon@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello!
>
> So as part of an incumbent process, it turns out that the namespaces all
> have to be declared on the document element or the downstream processing
> fails.  That's not correct, but I can't fix the process, so I wrote the
> following to make sure all the required namespaces could be declared on
> the document element.
>
>
> <xsl:function name="local:getNamespaces">
>  <xsl:param name="thisDoc" as="document-node()"/>
>  <!-- group descendant elements by namespace URI because we don't completely
trust the prefix to be unique -->
>  <xsl:for-each-group select="$thisDoc/descendant-or-self::element()"
>    group-by="namespace-uri-from-QName(resolve-QName(name(.), .))">
>    <xsl:variable name="QName" as="xs:QName"
select="current-group()[1]/resolve-QName(name(.), .)"/>
>    <xsl:variable name="prefix" as="xs:string?"
select="prefix-from-QName($QName)"/>
>    <xsl:variable name="namespace" as="xs:anyURI?"
select="namespace-uri-from-QName($QName)"/>
>    <!-- don't create a namespace for the default namespace; only if there's
a defined prefix (empty string = false) -->
>    <xsl:if test="$prefix">
>      <xsl:namespace name="{$prefix}" select="$namespace"/>
>    </xsl:if>
>  </xsl:for-each-group>
> </xsl:function>
>
>
> It works, but I find myself wondering how I could declare the return
> type of the function.
>
> as="namespace()" does not work; namespace() isn't a node test.
>
> I realize this is a weird case that's a workaround for a bug elsewhere
> in the process, but wanting to be able to extract and manipulate a
> sequence of namespaces seems like a reasonable thing for a function to
> do.
>
> What am I missing?
>
>
> --
> Graydon Saunders  | graydonish@xxxxxxxxx
> CC&s oferC)ode, C0isses swC! mC&g.
> -- Deor  ("That passed, so may this.")