Summary

This chapter described the syntax and meanings of patterns, whose main use in an XSLT stylesheet is to define which template rules apply to which nodes in the source document, but which are also used in the <xsl:key>,<xsl:number>, and <xsl:for-each- group > elements.

Patterns, although their syntax is a subset of that for XPath expressions, are evaluated in a different way to expressions, though we saw that the formal rules express the meaning of a pattern in terms of the corresponding expression.

The next chapter describes the library of standard functions that can be used within XPath expressions in a stylesheet