Based on bison version 1.19. Compatible with bison but with C++ support.
 Bison is a general-purpose parser generator that converts a grammar
 description for an LALR (BNF-like) context free grammar into a C/C++ program
 to parse that grammar. Once you are proficient with bison++ you can generate
 a wide range of language parsers, from those used in simple desk calculators
 to complex programming languages.