Learning context-free grammar rules from a set of program

The grammar of a programming language is important because it is used in developing program analysis and modification tools. Sometimes programs are written in dialects-minor variations of standard languages. Normally, grammars of standard languages are available but grammars of dialects may not be available. A technique for reverse engineering context-free grammar rules is presented. The proposed technique infers rules from a given set of programs and an approximate grammar is generated using an iterative approach with backtracking. The correctness of the approach, is explained and a set of optimisations proposed to make the approach more efficient. The approach and the optimisations are experimentally verified on a set of programming languages.