Package byacc

Berkeley Yacc, a parser generator

http://invisible-island.net/byacc/byacc.html

This package provides a parser generator utility that reads a grammar
specification from a file and generates an LR(1) parser for it. The
parsers consist of a set of LALR(1) parsing tables and a driver
routine written in the C programming language. It has a public domain
license which includes the generated C.

If you are going to do development on your system, you will want to install
this package.

General Commands
Command Description
yacc an LALR(1) parser generator