Implementing Context Patterns in the Glasgow Haskell Compiler

Markus Mohnen, Stefan Tobies

           Context patterns are a new non--local form of patterns, which
           allow the matching of subterms without fixed distance from
           the root of the whole term. Typical applications of context
           patterns are functions which search a data structure and
           possibly transform it, especially functions which operate
           on programs as data objects. In this paper we describe our
           approach on extending the Glasgow Haskell Compiler (ghc)
           with context patterns.