There are cases where using functions - especially memo functions - in match
patterns can be useful, but I don't think that's particularly the case here.
There are also cases where using global variables is effective, e.g if you
want to treat the first X sibling after a Y specially, the most effective way
might be
<xsl:variable name="special-Xs" select="//Y/following-sibling::X[1]"/>
<xsl:template match="$special-Xs"> (XSLT 3.0)
or
<xsl:template match="*[. intersect $special-Xs]"> (XSLT 2.0)
Michael Kay
Saxonica
> On 6 Jan 2017, at 17:56, Wendell Piez wapiez@xxxxxxxxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello XSL-List,
>
> I am having more and more occasions these days to handle HTML @class
> semantics, which as you probably know can be 'overloaded' in the sense
> that multiple values (NMTOKEN) of 'class' may have to be distinguished
> and handled separately.
>
> An idiom for matching any element .foo (CSS selector) could be
>
> <xsl:template match="*[tokenize(@class,'\s+')='foo')]">
> ...
> </xsl:template>
>
> This will match the element by virtue of the value being present on
> the @class, split apart at white space and compared (many-to-one) with
> =
>
> (That logic can of course be relegated to a stylesheet function call
> for neatness. It's true you can get an element matching more than one
> template this way: that's the idea.)
>
> Question: I can define a key, as in
>
> <xsl:key name="elements-by-class" match="*[matches(@class,'\S')]"
> use="tokenize(@class,'\s+')"/>
>
> then
>
> <xsl:template match="key('elements-by-class','foo')">
> ...
> </xsl:template>
>
> I regard this as a neat trick, and think it might be an "improvement"
> :-) but I suppose from one point of view at least, that may be
> arguable.
>
> What do readers think? Should I prefer a stylesheet function instead?
> (John Lumley what do you think?)
>
> Regards,
> Wendell
>
> --
> Wendell Piez | http://www.wendellpiez.com
> XML | XSLT | electronic publishing
> Eat Your Vegetables
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