Abstract

In this paper we study the problem of interoperability—combining constructs from two separate programming languages within one program—in the case where one of the two languages is dependently typed and the other is simply typed. We present a core calculus called SD, which combines dependently- and simply-typed sublanguages and supports user-defined (dependent) datatypes, among other standard features. SD has “boundary terms ” that mediate the interaction between the two sub-languages. The operational semantics of SD demonstrates how the necessary dynamic checks, which must be done when passing a value from the simply-typed world to the dependently typed world, can be extracted from the dependent type constructors themselves, modulo user-defined functions for marshaling values across the boundary. We establish type-safety and other meta-theoretic properties of SD, and contrast this approach to others in the literature. Categories and Subject Descriptors D.3.1 [Programming Languages]:

Citations