Re: [NTG-context] BNF grammar for ConTeXt (was: What happened with sectionworld?)

30 Apr 2009


      On Thu, Apr 30, 2009 at 10:16 AM, R. Bastian  wrote:
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On Thu, 30 Apr 2009 09:48:40 +0200
luigi scarso  scribit:
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R. Bastian:
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CONTEXT_SOURCE ::= PREAMBLE "\starttext" TEXT "\stoptext" |
CONTEXT_SOURCE
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TEXT ::= STARTSTOPS | SETUPS | DEFINES | OTHERS [ TEXT
luigi:
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To be general, i think
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MY_CONTEXT_SOURCE ::= MACRO* END
R. Bastian:
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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
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standard-ConTeXt
or minimal-ConTeXt or light-ConTeXt
ie a ConTeXt to use as "reference"
R. Bastian:
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Exactly what I need : standard, minimal and light
Exactly what can be hard to define and capture in a bnf .
wolfgang
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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