Polymorphic extractors for semantic and portable pattern matching (short paper)

Abstract

This paper introduces polymorphic extractors, a technique for tackling two main issues with the existing pattern matching techniques in functional languages. First, this technique defines semantic pattern matching rather than a syntactic one. Second, this technique solves the portability issue when defining a set of patterns based on different underlying data-structure design choices. Furthermore, polymorphic extractors can be further improved by performing optimizations and multi-stage programming. The key technique behind polymorphic extractors is using the tagless-final technique (a.k.a. polymorphic embedding/object algebras) for defining different extraction semantics over expression terms.