OMeta: an object-oriented language for pattern matching

This paper introduces OMeta, a new object-oriented language for pattern matching. OMeta is based on a variant of Parsing Expression Grammars (PEGs) [5]---a recognition-based foundation for describing syntax---which we have extended to handle arbitrary kinds of data. We show that OMeta's general-purpose pattern matching provides a natural and convenient way for programmers to implement tokenizers, parsers, visitors, and tree transformers, all of which can be extended in interesting ways using familiar object-oriented mechanisms. This makes OMeta particularly well-suited as a medium for experimenting with new designs for programming languages and extensions to existing languages.