[Rubygrammar-grammarians] Ruby Grammar Project

[Terence Parr]

On Nov 25, 2005, at 12:30 PM, MenTaLguY wrote:

> On Fri, 2005-11-25 at 10:53 -0800, Terence Parr wrote:
>> Cool.  Was wondering about that.  Let's do in Java (only stable v3
>> target at the moment) and then dump ASTs to disk and then compare.
>
> Yeah, that would definitely be a lot easier.
>
> Let's do it.
>
> I guess we need:
>
>  1. an on-disk format to dump the ASTs to
>
>  2. a program that dumps using the existing YACC grammar
>
>  3. a java program that dumps using the ANTLR grammar
>
>  4. a program in (language-of-choice) which compares dumped ASTs

Yup.

> I can do #2, you will probably want to do #3, and we can probably  
> defer
> #4 until we've got things reasonably close and get tired of visual
> inspection.  If we're careful about whitespace plain diff(1) might do.

Yep.  I usually dump in lisp form

( root child1 child2 ... )

XML format works too.

> Unfortunately I've found that MetaRuby's ParseTree isn't going to be
> comprehensive enough.  It just does individual methods, not arbitrary
> fragments or whole scripts.

Well, that's cool.  We'll check whole programs at a time.

> However, looking at Ruby's source, it apparently has a "ripper" build
> configuration which appears to dump parse trees somehow.  I'll
> investigate that, as it may dictate the ultimate format we use for #1.

Ah.  Sure.  Dumping in any format from an AST is easy.

Ter