Parametric Type Inferencing for Helium
Bastiaan Heeren, Jurriaan Hage · 2002
Abstract. Helium is a compiler for a large subset of Haskell under development at Universiteit Utrecht. A major design criterion is the ability to give superb error messages. This is especially needful for novice functional programmers. In this paper we document the implementation of the Helium type inferencer. For purposes of experimentation with various methods of type inferencing, the type inferencer can be parameterized in a number of ways. Among the instances we find not only standard algorithms such as M and W, but also more global type inferencers based on type graphs. 1