Experimental XSLT 4.0 extensions

This section describes features proposed for XSLT 4.0, to the extent they are implemented in Saxon 12.

Use of forwards compatibility mode (by specifying version="4.0", say), does not affect the way these extensions are handled: they are allowed if extensions are enabled, and disallowed if extensions are disabled, regardless of the effective version in the stylesheet.

Enabling syntax extensions not only allows the use of the XSLT extensions described in this section, it also allows XPath 4.0 extensions to be used in expressions and sequence types within the stylesheet, as described in Other XPath 4.0 extensions and elsewhere.

The xsl:item-type declaration
Match patterns
Conditional instructions
Extension instructions calling templates
Separator attribute
The xsl:match instruction
Iterating over maps and arrays
Grouping using break-when
Controlling duplicates on xsl:map
Creating arrays
Enclosing modes
Miscellaneous extensions