From: Ryan Davis <ryand-ruby@...>
Date: 2008-08-27T09:41:40+09:00
Subject: Re: Alternative to Parse::RecDescent


On Aug 26, 2008, at 13:04 , Lex Williams wrote:

> Is there a ruby alternative to perl's Parse::RecDescent , or java's
> ANTLR ?

If you're specifically looking for LL parser generators, you should  
first know that antlr is supposed to be able to generate ruby. Last  
time I took a poke at it the ruby functionality was broken and Terr  
was being a PITA about accepting patches so I didn't push any further.  
Maybe someone else has gotten it to work but I'm not going to try to  
work with antlr anymore. Terr is an impediment to his own project imho.

There are two versions of coco/r ported to ruby. I don't think either  
are being maintained (I'm the maintainer of one of them), but they work.

treetop, as mentioned, and a couple other PEG parser engines exist,  
but that is a different style of beast entirely.

On the L(aL)R side, there is racc and a couple others. racc doesn't  
seem to be maintained either, but it works. I use it for my  
ruby_parser project. The nice thing there is that the engine ships  
with ruby (but not the compiler). I'm wholly not a fan of LR myself,  
but this may still be your best option depending on what you want to do.

P.S. ANYTHING is a valid alternative to Parse::RecDescent... including  
nothing at all.