From: Clifford Heath <no@...>
Date: 2008-01-28T19:34:57+09:00
Subject: Re: Treetop parser (or PEG in general?) questions

Phrogz wrote:
> require 'rubygems'
> require 'treetop'
> 
> Treetop.load "t1.treetop"
> @parser = T1Parser.new
> @root = @parser.parse( "Hi 123\n\n" )

Just a tip: Treetop now uses my Polyglot gem, which hooks require,
so that instead of calling "Treetop.load 't1.treetop'", you can
just say:

require 'treetop'
require 't1'

If the .rb file is found first, that'll be loaded, if not, treetop
will compile 't1.treetop' (or 't1.tt', whichever you use).

In my CQL parser, I have a file cql.rb, which does the require 'treetop'
and require 'CQLParser', and also uses Polyglot to define a CQL load
function, so if you have a file "model.cql", you can just:

require 'cql'
require 'model'

and the model.cql file is compiled by the CQL parser (which itself
is created dynamically by Treetop if needed). Cute stuff.

Clifford Heath.