ANTLR Tree Grammar Generator and Extensions

A computer program implements two extensions of ANTLR (Another Tool for Language Recognition), which is a set of software tools for translating source codes between different computing languages. ANTLR supports predicated-LL(k) lexer and parser grammars, a notation for annotating parser grammars to direct tree construction, and predicated tree grammars. [“LL(k)” signifies “left-right, leftmost derivation with k tokens of look-ahead,” referring to certain characteristics of a grammar.]