From: Takaaki Tateishi <ttate@...>
Date: 2005-04-19T00:05:47+09:00
Subject: Re: BNF-like grammar specified DIRECTLY in Ruby

Eric Mahurin wrote:
> That is similar to what I'm doing.  A primary difference
> between what you are doing and I am is that for yours a rule is
> a proc/method and for mine a rule is an object.  I think the
> way I did it is cleaner, but having a rule as a proc does make
> it easier to have local variables in a rule. 

A rule of tdp4r is an instance of Rule, which consists of Proc objects and methods.
In order to handle a recursive rule easily, tdp4r uses methods.

> The samples you show parse strings.  Can you parse files
> without reading the whole thing in?

It's possible if you define methods shift and unshift.
A parser read a token using shift and push it back using unshift.

> Can you do things with or without a lexer?

tdp4r doesn't provide a function of a lexer.

Thanks,
-- 
Takaaki Tateishi <ttate@ttsky.net>