From: "Rob ." <rob.02004@...>
Date: 2005-11-10T01:11:05+09:00
Subject: Re: RUBY GRAMMAR

On 11/9/05, puellula@gmail.com <puellula@gmail.com> wrote:
> Can you help me? I have to write a Ruby Editor + Parser
> with Java

I'm curious why do you *have* to write a Ruby Editor + Parser with Java?

If you wish to parse Ruby code in Java, I recommend using the JRuby
parser (http://jruby.sourceforge.net/).

If you want to write a Ruby Editor in Java, there are existing editor
efforts underway that would welcome enthusiastic developers helping
out. I'm writing the jEdit Ruby Editor Plugin
(http://jedit.org/ruby/). There are also Eclipse based plugins
underway, like Ruby Development Tools and RadRails.

If you want to use JRuby, here is some example parsing code:

 DefaultRubyParser parser = new DefaultRubyParser();
 parser.init(new RubyParserConfiguration());
 LexerSource source = LexerSource.getSource(file, content);

 RubyParserResult result = parser.parse(source);
 Node node = result.getAST();

 NodeVisitor visitor = new RubyNodeVisitor();

 if (node != null) {
   node.accept(visitor);
 }

 List members = visitor.getMembers();

You implement your own version of the JRuby NodeVisitor interface,
which looks something like this:

class RubyNodeVisitor extends AbstractVisitor { ...
    protected void visitNode(Node node) { ...
    public void visitBlockNode(BlockNode node) { ...
    public void visitNewlineNode(NewlineNode node) { ...
    public void visitModuleNode(ModuleNode node) { ...
    public void visitClassNode(ClassNode node) { ...
    public void visitDefnNode(DefnNode node) { ...
    public void visitDefsNode(DefsNode node) { ...
    public void visitScopeNode(ScopeNode node) { ...
    // etc
}

cheers,
Rob