A Family of Syntax De nition Formalisms

In this paper we design a syntax deenition formalism as a family of formalisms. Starting with a small kernel, various features for syntax de-nition are designed orthogonally to each other. This provides a framework for constructing new formalisms by adapting and extending old ones. The formalism is developed with the algebraic speciication formalism Asf+Sdf. It provides the following features: lexical and context-free syntax, variables, disambiguation by priorities, regular expressions, character classes and modular deenitions. New are the uniform treatment of lexical syntax, context-free syntax and variables, the treatment of regular expressions by normalization yielding abstract syntax without auxiliary sorts, regular expressions as result of productions and modules with hidden imports and renamings. Note: Supported by the Dutch Organization for Scientiic Research (NWO) under grant 612-317-420: Incremental parser generation and context-dependent disambiguation, a multidisciplinary perspective.