Abstract

We present a minimal extension of the Hindley/Milner system to allow for overloading of identi ers. Our approach relies on a combination of the HM(X) type system framework with Constraint Handling Rules (CHRs). CHRs are a declarative language for writing incremental constraint solvers. CHRs allow us to precisely describe the relationships among overloaded identi ers. Under some sucient conditions on the CHRs we achieve decidable type inference and the semantic meaning of programs is unambiguous. Our approach allows us to combine open and closed world overloading. We also show how to deal with overlapping de nitions.

Citations