From: "M. Edward (Ed) Borasky" <znmeb@...>
Date: 2007-07-27T23:12:28+09:00
Subject: Re: How to write a ruby compiler using Java???

Charles Oliver Nutter wrote:
> shiwei zhang wrote:
>> Hi,
>>
>>   I am using Java to write a Ruby compiler. I build up the editor by
>> Java SWing.
>>   Now the tough task for me is syntax parser. Does someone have some
>> suggestions about how to check the validity of ruby codes in the
>> editor and how to mark the grammar-incompliant points? Are there some
>> plugins I can make use of, or do I need to parse the grammar by
>> myself? If I want to parse the grammar by myself, where is the
>> complete grammar definition for ruby lang? E.G., like C99(ISO
>> 9899:1999) for C lang. Seems there is not a complete grammar
>> definition for ruby lang at http://www.ruby-lang.org.
>>   Many Thanks.
> 
> There are basically two known good grammars for Ruby. One is the
> original Ruby 1.8 YACC-based parser grammar and variations of it (JRuby,
> Rubinius, and Ruby.NET/IronRuby all use variations or ports of that
> grammar). The other is an ANTLR grammar used by the XRuby project. Only
> the YACC grammars are known to be "compatible" at present, but XRuby's
> ANTLR grammar seems to be very close.
> 
> If you are looking for a grammar/AST to use for an editor, your best bet
> is probably JRuby's. Not only do we have the most popular grammar and
> AST for Java-based editors, but we have an additional set of utility
> code to allow inspecting, reversing, and manipulating the AST. NetBeans,
> Eclipse, and JEdit-based Ruby editors are based on our parser and AST,
> as is (I believe) the IntelliJ Ruby editor. We also have been building
> the JRuby Ruby-to-bytecode compiler based on that AST.
> 
> - Charlie
> 
> 
Just out of curiosity, where do the "Zen" tools (ParseTree, Ruby2Ruby,
etc.) fit into this scheme of things?

Also, is there such a thing as Test Driven/Behavior Driven parser
development? Should there be? ;)