A framework for extensible languages

Extensible programming languages such as SugarJ or Racket en-able programmers to introduce customary language features as ex-tensions of the base language. Traditionally, systems that support language extensions are either (i) agnostic to the base language or (ii) only support a single base language. In this paper, we present a framework for language extensibility that turns a non-extensible language into an extensible language featuring library-based exten-sible syntax, extensible static analyses, and extensible editor sup-port. To make a language extensible, our framework only requires knowledge of the base language’s grammar, the syntax for import statements (which activate extensions), and how to compile base-language programs. We have evaluated the generality of our frame-work by instantiating it for Java, Haskell, Prolog, JavaScript, and System Fω, and by studying existing module-system features and their support in our framework