Re: [Docutils-develop] Design - EBNF

[David G. <go...@us...>]

Dethe Elza wrote:
> Can reStructured Text be defined in Extended Backus-Naur Form?

I don't know if it can or not; I've forgotten all I ever knew about
formal grammars.  There are at least two problems with EBNF for
reStructuredText: indentation and lookahead.  Python's grammar has a
solution for indentation; I don't know if it's applicable to
reStructuredText or not.  I don't know about lookahead.

Ed Loper did some work on this early last year.  His results are
here:

    http://www.cis.upenn.edu/~edloper/pydoc/stminus-001.html

I agree that it would be good if reStructuredText could be expressed
in EBNF.

> This would also separate reStructured Text as a concept and language
> from the particular state-machine architecture and implementation.

That's why the spec was written before the parser, although they have
evolved together since.  I've tried to keep the spec current, so that
anyone could take it and implement another parser, if they were so
inclined.

-- 
David Goodger  <go...@us...>  Open-source projects:
  - Python Docutils: http://docutils.sourceforge.net/
    (includes reStructuredText: http://docutils.sf.net/rst.html)
  - The Go Tools Project: http://gotools.sourceforge.net/