The Functional Programming Language XSLT - A proof through examples

Until now it was believed that although XSLT is based on functional programming ideas, it is not as yet a full functional programming language, as it lacks the ability to treat functions as a first-class data type. Based on numerous concrete XSLT implementations of some of the major functional programming design patterns, including some of the most generic list-processing and tree-processing functions, this article provides ample proof that XSLT is in fact a full-pledged functional programming language. The presented code forms the base of a first XSLT functional programming library. It is emphasized that a decision to include higher-order functions support in XPath 2.0 will make functional programming in XSLT even more straightforward, natural and convenient.