Ornaments: exploiting parametricity for safer, more automated code refactorization and code reuse (invited talk)

Abstract

Inductive datatypes and parametric polymorphism are two key features introduced in the ML family of languages, which have already been widely exploited for structuring programs: Haskell and ML programs are often more elegant and more correct by construction. Still, we sometimes need code to be refactored or adapted to be reused in a slightly different context. While the type system is considerably helpful in these situations, by automatically locating type-inconsistent program points or incomplete pattern matchings, this process could be made safer and more automated by further exploiting parametricity. We propose a posteriori program abstraction as a principle for such code transformations.