Hello, I think, XSLT 3.0 instruction xsl:map is quite useful which can produce complex XPath 3.1 maps, where XPath 3.1 syntax map { ... } may have limitations. Xalan Java XSLT 3.0 project now has ...

This directory contains the Java source code required to compile a Java callout for Apigee that does XSLT. There's a built-in policy that does XSLT; this callout is ...