Well-typed islands parse faster

Abstract

This paper addresses the problem of specifying and parsing the syntax of domain-specific languages (DSLs) in a modular, user-friendly way. We want to enable the design of composable DSLs that combine the natural syntax of external DSLs with the easy implementation of internal DSLs. The challenge in parsing these DSLs is that the composition of several languages is likely to contain ambiguities. We present the design of a system that uses a type-oriented variant of island parsing to efficiently parse the syntax of composable DSLs. In particular, we argue that the running time of type-oriented island parsing doesn't depend on the number of DSLs imported. We also show how to use our tool to implement DSLs on top of a host language such as Typed Racket. © 2013 Springer-Verlag.