A Type Safe Calculus for Generating Syntax-Directed Editors

Editor calculi make it possible to describe the actions of syntax-directed editing and provide guarantees of safety through their specialized type system: Well-typed editor scripts produce well-formed programs. So far, such calculi have been language-specific. In this paper we present a generalized editor calculus, which can be used to specify a specialized syntax-directed editor for any language, given its abstract syntax. Moreover we show how to implement an editor generator that allows one to generate an editor calculus-based syntax-directed editor from a language specification. The generalized editor calculus can be encoded into a simply typed lambda calculus, extended with pairs, booleans, pattern matching and fixed points. This implies a general type safety result that holds for any instantiation.