Saxon

The reason is that the XPath 3.1 grammar (production ElementTest) doesn't allow it.

Is there a reason for that? We decided that there isn't, so the XPath 4.0 grammar does allow it.

On the current build I'm getting

Error in xsl:variable/@as on line 5 column 47 of test.xsl:
  XPST0003  Wildcard syntax in item types requires 4.0 to be enabled

but it's possible there are earlier releases in which we allow the syntax through without checking.

For interest here's my test case (which is attached as well):

<?xml version="1.0" encoding="UTF-8" ?>
<xsl:stylesheet version="3.0"
                xmlns:myns="http://myns"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="xml" indent="yes" />

  <xsl:variable name="var01" as="element(Q{http://myns}*)+">
    <myns:node>var01</myns:node>
  </xsl:variable>

  <xsl:template name="xsl:initial-template">
    <root>
      <xsl:copy-of select="$var01" />
      <xsl:call-template name="template01" />
    </root>
  </xsl:template>

  <xsl:template name="template01" as="element(Q{http://myns}*)+">
    <myns:node>template01</myns:node>
  </xsl:template>
</xsl:stylesheet>

In 12.5 and 12.4 I get this error (which is a bit odd as it says the node is in the wrong namespace, but the supplied value shows it is in the correct namespace):

Type error on line 20 column 16 of As.xslt:
  XTTE0505  The required item type of the result of template template01 is Q{http://myns}*;
  the supplied value <myns:node> does not match. The node is in the wrong namespace
In template template01 on line 19 column 66 of As.xslt:
     invoked by xsl:call-template at file:/L:/Tests/XSLT/XSLT_As/As.xslt#15
In template xsl:initial-template on line 12 column 45 of As.xslt:
The required item type of the result of template template01 is Q{http://myns}*; the supplied value <myns:node> does not match. The node is in the wrong namespace

In 12.3 I get:

Error in xsl:variable/@as on line 8 column 61 of As.xslt:
  XPST0003  Unexpected <prefix:*> after '(' in SequenceType
Error in xsl:template/@as on line 19 column 66 of As.xslt:
  XPST0003  Unexpected <prefix:*> after '(' in SequenceType
Errors were reported during stylesheet compilation

I should have said I'm using SaxonJ-HE.

It looks as if the check to disallow this syntax unless 4.0 is enabled was added after the last maintenance release; so the code as issued is probably allowing the 4.0 syntax but not implementing the semantics.

In fact I think I made this change in the course of investigating bug #6532

It looks as if the check to disallow this syntax unless 4.0 is enabled was added after the last maintenance release; so the code as issued is probably allowing the 4.0 syntax but not implementing the semantics.

I don't know what the semantics are, but If I add the following to the variable (and get rid of the error related to the template):

<myns:node2>var01</myns:node2>

I get both nodes output:

<myns:node>var01</myns:node>
<myns:node2>var01</myns:node2>