From: George Moschovitis <george.moschovitis@...>
Date: 2005-10-14T18:39:33+09:00
Subject: Re: [ANN] grammar-0.5

Hey, just what I needed for a pet project of mine ;-)

Thanks,
-g.


On 10/14/05, Eric Mahurin <eric_mahurin@yahoo.com> wrote:
> Well, I'm finally doing a release of my grammar package:
>
> http://rubyforge.org/projects/grammar/
>
> I also released cursor-0.9 to go along with it:
>
> http://rubyforge.org/projects/cursor/
>
> Here are some of the features of it:
>
> * BNF-like grammar written directly in Ruby (by overriding +,
> |, *, &, ~, etc operators)
>
> * lexer and parser grammars are specified in exactly the same
> way - one parses characters and the other tokens
>
> * can write a lexer-free parser
>
> * may define tokens however is appropriate
>
> * variety of Cursor options for connecting lexer to parser
>
> * can put lexer and parser in different threads
>
> * defaults to one character/token lookahead, but can extend to
> arbitrary lookahead where needed
>
> * autogenerates flattened code by using a macro-like facility
>
> * ruby actions easily specified in blocks
>
> * lots of convienent Grammar methods to combine and manipulate
> grammars
>
>
> TODO:
>
> * error reporting needs work.  File/line/column numbers is
> needed
>
> * Cursor::Producer (multithreaded lexer cursor) needs some
> love.  It doesn't have a very robut interface.
>
> * various small API changes.  need more examples to see what
> would be good to have.
>
> * better testing.  only have partial random testing.
>
>
> I also have to samples that you can look at:
>
> - tcl interpreter: a complete tcl parser (no lexer needed) and
> interpreter written in under 150 lines of ruby code.  The
> example fact.tcl shows a recursive proc being defined and used
> in tcl.
>
> - infix 2 postfix expression converter: shows a lexer and
> parser and how they can be multi-threaded.  converts an infix
> expression into a postfix expression (looks like Joy) returned
> in a simple array.
>
>
>
>
>
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>


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