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Re: union operator and predicates in XSLT patterns

• From: "G. Ken Holman" <gkholman@CraneSoftwrights.com>
• To: "xml-dev@lists.xml.org" <xml-dev@lists.xml.org>
• Date: Mon, 24 Jan 2011 12:19:32 -0500

I missed mentioning that a predicate can contain any expression, so a 
sequence expression *is* allowed in the predicate of an expression 
used in a match.

Note that the terminology used is that a "pattern" is that subset of 
XPath expressions suitable for use in a match expression.

See XSLT 2 Section 5.5.2 for what is allowed in a pattern:

   http://www.w3.org/TR/2007/REC-xslt20-20070123/#pattern-syntax

I hope this helps.

. . . . . . . Ken

At 2011-01-24 12:13 -0500, I wrote:
>At 2011-01-24 17:06 +0000, HILLMAN, Tomos wrote:
>>Hi; just a quick query for my own understanding.  Apologies if I've 
>>gotten the wrong list.
>
>XSLT and XPath questions would be better posted to the following list:
>
>   http://www.mulberrytech.com/xsl/xsl-list
>
>There are a number of subscribers who would enthusiastically respond 
>to such questions.
>
>>I wanted to use both a union and operator in an XLST template, i.e. 
>>match="(div1|div2)[not(@role)]" (simplified).
>
>Nope ... not allowed ... the parentheses grouping the union is not allowed.
>
>You have to write the above as:
>
>   match="div1[not(@role)] | div2[not(@role)]"
>
>>This is, I think, equivalent in XPath 2.0 as 
>>"/*//(div1|div2)[not(@role)]", which I would expect to follow the 
>>rule for patterns in XSLT (the node $N matches pattern PAT if $N is 
>>a member of expression "root($N)//(PAT)".  However, this shows as invalid.
>>
>>Can someone explain this to me? :)
>
>Simple restriction of the syntax.  The parentheses are a sequence 
>operator, in effect creating the sequence of the union of div1 and 
>div2.  Sequences are not allowed in match patterns.
>
>Sequences are, of course, available to use in select= expressions.
>
>I hope this helps.
>
>. . . . . . . . . Ken


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• References:
  • union operator and predicates in XSLT patterns
    • From: "HILLMAN, Tomos" <tomos.hillman@oup.com>
  • Re: union operator and predicates in XSLT patterns
    • From: "G. Ken Holman" <gkholman@CraneSoftwrights.com>