Take a look at the handout of my presentation.


What is it?

The YPlayer Program is a teaching and debugging tool to aid in the study of language parsing and the design of language parsers. The user supplies YPlayer with an input file, a lex specification, and a yacc syntax specification. YPlayer will then compile the specifications into an executable using GNU flex, GNU bison, and a C compiler. The resultant executable is fed the input file and run. The debugging output from this execution is combined with other information gathered at compile time into a "YPEG" file. This file contains all the information needed to construct exactly what the lexer and parser did to the input.


  • Supports GNU bison and flex
  • Displays State Table with Rules
  • Displays Parse Stack
  • Displays Parse Tree

License & Distribution

Copyright (C)1999 Arun Rodrigues, Vincent Freeh.

This program is free software; you can redistribute it and/or modify it under the terms of the Artistic Liscence as provided with this program. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


The YPlayer Program was written by Arun Rodrigues under the direction of Dr. Vincent Freeh Funding was provided by the Notre Dame Office of Information Technology.