Let is not supported in XPath-CodePudding

Recently I upgraded my server and the following XSLT with Saxonb-XSLT stopped working:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    exclude-result-prefixes="#all"
    version="3.0">

  <xsl:output cdata-section-elements="title"/>

  <xsl:mode on-no-match="shallow-copy"/>

  <xsl:template match="title[ends-with(., 'Apple') or ends-with(., 'Samsung') or ends-with(., 'Banana')]">
      <xsl:copy>
          <xsl:value-of select="let $words := tokenize(., '\s ') 
               return (subsequence($words, 1, count($words) - 2), $words[last()], $words[last() - 1])"/>
      </xsl:copy>
  </xsl:template>

</xsl:stylesheet>

I get error:

  XPST0003: XPath syntax error at char 0 on line 13 in {let $}:
    'let' is not supported in XPath

I haven't upgraded saxonb-xslt (Saxon 9.1.0.8J from Saxonica). Anyone has idea why it is not working properly?

CodePudding user response：

You could bypass the need for let and any related version or licensing complications by rewriting your template to use an XSLT xsl:variable statement rather than an XPath 3.0 let statement:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns:xs="http://www.w3.org/2001/XMLSchema"
                exclude-result-prefixes="#all"
                version="2.0">

  <xsl:output cdata-section-elements="title"/>

  <xsl:mode on-no-match="shallow-copy"/>

  <xsl:template match="title[   ends-with(., 'Apple') 
                             or ends-with(., 'Samsung') 
                             or ends-with(., 'Banana')]">
    <xsl:variable name="words" select="tokenize(., '\s ')"/>
    <xsl:copy>
        <xsl:value-of select="subsequence($words, 1, count($words) - 2), 
                              $words[last()], 
                              $words[last() - 1]"/>
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>

CodePudding user response：

The let binding is part of XPath 3 I think, as that it is not supported completely in XSLT 3.0 before Saxon 9.8 HE as that is the first Saxon open-source release to support the final XSLT 3.0 with XPath 3 recommendation. You might find that using version="3.0" and then XPath 3 expressions using let work also in 9.7 and perhaps 9.6 but in even older releases Saxon (at least the open-source edition) is an XSLT 2.0 processor with XPath 2.0 support and doesn't support any XPath 3 expressions (like let).

The literal error message 'let' is not supported in XPath might suggest that that release had some support for let in XQuery but I don't recall details and I haven't checked.

It is not clear which version of Saxon you used before your upgrade and which one after it or what kind of "update" you did.

CodePudding user response：

You mention Saxon 9.1.0.8J from Saxonica. That is a very old release indeed (2009), and it would never have been able to run this stylesheet.

Somehow your "upgrade" has left you running an older Saxon release, I fear.

The current version is 10.6.