Safe Run-time Overloading

Abstract

We present a functional language featuring a form of dynamic overloading akin to message passing in object oriented languages. We give a dynamic semantics describing a non-deterministic evaluation, as well as a type discipline (static semantics) supporting type inference. The type system ensures that a well-typed program has a correct execution, unique up to a semantic equivalence relation, and allows this execution to proceed deterministically, while resolving overloading at run-time.