DrawGrammar is a tool to draw railroad diagrams of an EBNF grammar. It is available as an interactive demo and as a command-line tool.
It's licensed under the MIT license. It's available on OPAM. Its source code is on GitHub.
Questions? Remarks? Bugs? Want to contribute? Open an issue!
The simplest way is to use the interactive demo, load examples and play with the settings.
If you want to use it locally as a command-line tool, install it from OPAM:
$ opam install DrawGrammar
Then create a my_grammar.iso-ebnf file containing, for example:
expr = term, { ( '+' | '-' ) , term };
term = { factor, ( '*' | '/' ) }, factor;
factor = integer | '(', expr, ')';
integer = [ '-' ], digit, { digit };
digit = '0' | '1' | '...' | '9';
And draw it:
$ draw_grammar my_grammar.iso-ebnf
If you want to tweak settings, the help is accessible using:
$ draw_grammar --help
If you want to use the development version on the command line, you can:
$ opam pin add General --dev-repo $ opam pin add DrawGrammar --dev-repo
This always matches the version used in the interactive demo.