NAME

y2l - Yacc to LaTeX grammar pretty printer

SYNOPSIS

y2l [-- options] file
Options:
[-d] [-h] [-O] [-O{0,1,2}] [-p] [-t{regexp,file}] [-v]

DESCRIPTION

This utility takes a yacc(1) grammar description file and generates an EBNF (Extended Backus-Naur Form) grammar from it. By default, the output will be a LaTeX(1) longtable environment, that can be \input{} into any LaTeX document. Automatic substitution of symbolic terminals can also be taken care of. Options control whether any optimization should be done on the grammar, and whether plain ASCII output should be generated instead.

OPTIONS

-d: Write out debugging information to standard error.
-h: Display a short usage summary on standard output and exit.
-O: Optimize the yacc grammar. This basic optimization will look for empty rules to make non-terminals optional. It also recursively generates choice groups and optional groups and elements based on common prefix and suffix token lists.
-O0: Turn off optimization.
-O1: This gives the same optimization as the regular -O option.
-O2: Do basic optimization. In addition, multiple rules for the same non-terminal are combined as a choice group. Rules that were optimized by the first phase as optional non-terminals are converted into repetitive rules if possible.
-p: Generate plain ASCII output rather than LaTeX output.
-tregexp: Use the provided regular expression to determine whether a terminal is a lexical token rather than a literal. This is useful for grammars where literal tokens represent string literals that differ only in that the string literals are all lowercase versions of the token. Since this is a fairly common practise in yacc grammars, this option ha sbeen provided.
-tfile: Use the provided file as a mapping between literal tokens and the literal strings they represent. Each line in the file should contain two identifiers: the first one is the lexical token, and the second one is the literal string it represents.
-v: Display the program version information on standard error prior to doing any processing.

BUGS

While no known bugs seem to exist, there are probably quite a few unknown bugs.

AUTHOR

Kris Van Hees <aedil@alchar.org>