From: Phil Tomson <rubyfan@...>
Date: 2008-02-29T12:50:55+09:00
Subject: Re: TreeTop: dealing with Grammars in multiple files?

On 2/6/08, Clifford Heath <no@spam.please.net> wrote:
> Phil Tomson wrote:
>  > I know that you can include one grammar into another like so:
>  >
>  > grammar foo
>  >   include Bar_grammar
>  > end
>  >
>  > But what if Bar_grammar is defined in a different file?  I tried:
>  >
>  > load_grammar "Bar_grammar"
>  > grammar Foo
>  >   include Bar_grammar
>  > end
>  >
>  > but that doesnt' work.
>
>
> I haven't done this, but I think I might have said this was the
>  way to compose grammars. I suspect I was wrong, and that what you
>  need to do is to require both grammars, then re-open one of the
>  generated parser classes (which includes the module for that
>  grammar), and simply include the other grammar.
>
>  BTW, load_grammar is deprecated - in fact I thought it had been
>  removed. Are you using an old gem? The current incantation is
>  to call Treetop.load, or just to simply require the .treetop
>  file (which gets Polyglot to load it for you).
>
>  The file to be required may be called with either a .tt or .treetop
>  extension.


sorry for the long delay... just got back to this problem.

So you're saying that I could have two files each which defines a grammar:
  #keywords.treetop
  grammar Keywords
     ...
  end

  #Foo.treetop
  grammar Foo
    ...
  end

OK, so now I've got keywords.treetop and Foo.treetop, so are you
saying that I would then do something like:

  #main.rb
  require "keywords"
  require "Foo"

And then open the Foo module like so:

  module Foo
    include Keywords
  end

... or something like that??

Phil