* Tim Bunce wrote in perl.perl6.internals: >Here's a related idea: write a tool that reads BNF grammar, such as >http://java.sun.com/docs/books/jls/third_edition/html/syntax.html >http://java.sun.com/docs/books/jls/third_edition/html/grammars.html >and writes a parser in Perl 6 for that grammar.
I would be very interested in (using) a tool that reads many types of formal grammars and makes it easy to transform them to other formalisms. I am currently finishing up a free software library that decides any context-free language and the intersection and complement of languages it decides, focused on validation against web standards (is this string a syntactically correct 'mailto' URL, HTTP header value, JSON document, HTML attribute value, etc.) For it to be useful, the grammars for the various specifications need to be in a format my library understands; unfortunately there are very many BNF variants in use (the IETF generally uses its ABNF, the W3C tends to use the EBNF format defined in the XML specification, ...) and my library accepts only its own formalism (an XML format based on RELAX NG, a schema language for XML document validation). Tools that can read these BNF variants into a common object model, or otherwise make it easy to convert one formalism into another would be the main missing link to put my library into practical use in tools like <http://validator.w3.org/>. So work on the first half of the problem above would be very welcome. My plan is in principle to make my formalism sufficiently powerful so that all these BNF variants can be mapped 1:1 to it; then get people to extract and convert the grammars in the various specifications, and put them in some repository. From there on, using them for other formalisms like Perl 6 Rules would start with simple tree transformations rather than writing another parser (or at least comperatively simple, if you are bad at writing parsers like I am). -- Björn Höhrmann · mailto:[EMAIL PROTECTED] · http://bjoern.hoehrmann.de Weinh. Str. 22 · Telefon: +49(0)621/4309674 · http://www.bjoernsworld.de 68309 Mannheim · PGP Pub. KeyID: 0xA4357E78 · http://www.websitedev.de/
