A General Framework for Embedding Domain Specific Languages into Object-Oriented Programming Languages

In this paper, we introduce a general framework of language embedding in OO host languages. Unlike other approaches, which embed object language programs as nested calls to functions or data constructors, our framework embeds object language programs as a chain of method invocations. Our framework allows embedding a wider range of object language grammars into an OO host language, while still allowing object language programs to be type checked by the host language compiler and to run efficiently at run time. We demonstrate our framework using ELIA, our extension to Java with automatically constructed parameters (ACPs), and show how we can encode the parser, AST builder, type checker, and interpreter for the simply typed lambda calculus (STLC) in a concrete syntax without redundant brackets or commas. Our framework is only based on the basic OO features, generics, and ACPs, and do not require higher-order functions or generalized abstract data types (GADTS) in the host language. It is a generalization of our previous framework [34], which can be fully implemented in Java without ACPs.