Abstract

Also published as FOX Memorandum CMU-CS-FOX-99-02 We show that a type system based on the intuitionistic modal logic S4 provides an expressive framework for specifying and analyzing computation stages in the context of typed lambda-calculi and functional languages. We directly demonstrate the sense in which our calculus captures staging, and also give a conservative embedding of Nielson & Nielson's two-level functional language in our language, thus proving that binding-time correctness is equivalent to modal correctness. In addition, our language can express immediate evaluation and sharing of code across multiple stages, thus supporting run-time code generation as well as partial evaluation.

Citations