Schrijvers, Tom × Peyton Jones, Simon Chakravarty, Manuel Sulzmann, Martin #
ACM Sigplan Notices vol:43 issue:9 pages:51-62
International Conference on Functional Programming edition:13 location:Victoria, Canada date:22-24 September 2008
We report on an extension of Haskell with open type-level functions and equality
constraints that unifies earlier work on GADTs, functional dependencies,
and associated types. The contribution of the paper is that we
identify and characterise the key technical challenge of entailment checking; and we give a novel, decidable, sound, and
complete algorithm to solve it, together with some practically-important variants.
Our system is implemented in GHC, and is already in active use.