I must say, I find this restriction somewhat
amazing. I assume it's intended to reduce the
complexity of writing XSL processors?
Actually I stated the restriction wrongly. Some patterns in XSLT can
contain variable references, but the ones used in the match attribute of
xsl:template and xsl:key can't.
The restriction was a misguided attempt to eliminate the possibility of
circularities, in constructs like:
To circumvent the restriction, you need to use an xsl:choose inside the
The restriction has been lifted in XSLT 2.0.
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list