On Thu, Apr 30, 2009 at 10:16 AM, R. Bastian <rbastian@free.fr> wrote:

> On Thu, 30 Apr 2009 09:48:40 +0200
> luigi scarso <luigi.scarso@gmail.com> scribit:
>
> > R. Bastian:
> >
> > > CONTEXT_SOURCE ::= PREAMBLE "\starttext" TEXT "\stoptext" |
> CONTEXT_SOURCE
> > >>>  TEXT ::= STARTSTOPS | SETUPS | DEFINES | OTHERS [ TEXT
> > >>
> > >> luigi:
> >
> > >   To be general, i think
> > >>   MY_CONTEXT_SOURCE ::= MACRO* END
> > >>
> > >
> > R. Bastian:
> >
> > > I dont understand the sense of "\end\starttext"
> >
> > sense==semantic
> >
> > "\end""\starttext" is a valid string for a hypothetical  bnf grammar of
> > ContTeXt
> > which is not valid for your bnf ;
> > "\end""\starttext""\stoptext" is in your bnf grammar
> > and has the same semantic of  "\end""\starttext" .
> >
> > The point is : a bnf for Context can be hard to define
> >
> >
> >  luigi:
> >
> > think that a bnf or lpeg grammar is really useful for a sort of
> > >> standard-ConTeXt
> > >> or minimal-ConTeXt or light-ConTeXt
> > >> ie a ConTeXt to use as "reference"
> > >>
> > >
> > R. Bastian:
> >
> > > Exactly what I need : standard, minimal and light
> > >
> >
> > Exactly what can be hard to define and capture in a bnf .
> >
> > wolfgang
> >
> > >
> > > How could a BNF grammar help to learn ConTeXt,
> >
> > a bnf can help to build a syntax checker, a highlighter etc.
> > Actually the only way to say that you have a valid ConTeXt string
> > is running context on that string .
> >
> > The semantic is another story.
>
> OK - but isn't it not worth to try it ?
>
sure, and I encourage you to go on and possibly write something x next
eurotex.

My suggestions to start :
1) define a **simple but significative** domain ,ie "this grammar is for
subset of ConTeXt language dedicated to variable-data pdf forms"
2) make a bnf grammar spec
3) build a parser lex/yacc for 2)
4) make a lpeg grammar
5) user lpeg inside context for 3)

PS
it was just a coincidence , but for other reasons I have found this link
http://martinfowler.com/dslwip/

-- 
luigi