GNU Bison has use parsing
GNU Bison, commonly known as Bison, is a parser generator that is part of the GNU Project. Bison reads a specification in the BNF notation (a context-free language), warns about any parsing ambiguities, and generates a parser that reads sequences of tokens and decides whether the sequence conforms to the syntax specified by the grammar.
The generated parsers are portable: they do not require any specific compilers.  Bison by default generates LALR(1) parsers but it can also generate canonical LR, IELR(1) and GLR parsers.In POSIX mode, Bison is compatible with Yacc, but also has several extensions over this earlier program, including