From m.liedl at gmx.de  Sun Oct  7 11:24:17 2007
From: m.liedl at gmx.de (Markus Liedl)
Date: Sun, 07 Oct 2007 17:24:17 +0200
Subject: [grammarians] the project 'Ruby top down grammar'
Message-ID: <20071007152417.219840@gmx.net>

hello list,

My name is Markus Liedl. I'm working on an alternative Ruby grammar.

It is currently only working within Emacs, but I intend to write  a grammar interpreter in Ruby, so one can use Ruby as a host language instead of Emacs Lisp.

Have a look and tell me what you think about it.

It's hosted on rubyforge, project name ruby-tp-dw-gram; you can check it out via

  svn checkout svn://rubyforge.org/var/svn/ruby-tp-dw-gram

See below for the top of the README file.

thanks,
Markus Liedl








                   Ruby Top Down Grammar

This project tries to implement a reusable top-down grammar of
the Ruby language.

It may be used to
  * bootstrap a pure ruby vm
  * advanced syntax highlighting in emacs

This Ruby grammar can be classified as a non-exhaustively
backtracking, non-deterministic top-down parser.

It is close to a "Parsing expression grammar", although it uses two features, modes and marks, which make me unsure whether this
categorization fits.

The ruby grammar is written in a parsing specific language in Lisp syntax. This decision was made because it is simple to parse. An implementation of this definition language takes a few hundred lines (well, in elisp).  This facilitates bootstraping.

Another goal was to avoid 'semantic actions' written in an arbitrary language. This is necessary for seriously targetting multiple host languages.

...

From mental at rydia.net  Sun Oct 14 11:19:00 2007
From: mental at rydia.net (MenTaLguY)
Date: Sun, 14 Oct 2007 11:19:00 -0400
Subject: [grammarians] the project 'Ruby top down grammar'
In-Reply-To: <20071007152417.219840@gmx.net>
References: <20071007152417.219840@gmx.net>
Message-ID: <1192375140.6179.2.camel@localhost.localdomain>

On Sun, 2007-10-07 at 17:24 +0200, Markus Liedl wrote:
> My name is Markus Liedl. I'm working on an alternative Ruby grammar.

> It is currently only working within Emacs, but I intend to write  a
> grammar interpreter in Ruby, so one can use Ruby as a host language
> instead of Emacs Lisp.

Cool!  Both the grammar and the grammar interpreter sound like useful
projects.  How complete is its coverage of the Ruby grammar currently?

-mental
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
Url : http://rubyforge.org/pipermail/rubygrammar-grammarians/attachments/20071014/733d5056/attachment.bin 

From m.liedl at gmx.de  Mon Oct 15 01:56:35 2007
From: m.liedl at gmx.de (Markus Liedl)
Date: Mon, 15 Oct 2007 07:56:35 +0200
Subject: [grammarians] the project 'Ruby top down grammar'
In-Reply-To: <1192375140.6179.2.camel@localhost.localdomain>
References: <20071007152417.219840@gmx.net>
	<1192375140.6179.2.camel@localhost.localdomain>
Message-ID: <20071015055635.321810@gmx.net>


> On Sun, 2007-10-07 at 17:24 +0200, Markus Liedl wrote:
> > My name is Markus Liedl. I'm working on an alternative Ruby grammar.
> 
> > It is currently only working within Emacs, but I intend to write  a
> > grammar interpreter in Ruby, so one can use Ruby as a host language
> > instead of Emacs Lisp.
> 
> Cool!  Both the grammar and the grammar interpreter sound like useful
> projects.  How complete is its coverage of the Ruby grammar currently?
> 
> -mental

Well, I'm still debugging the grammar and still find minor bugs.

The major missing parts are currently
 * here-doc
 * %Q %W regexp

So, I've not yet parsed huge amounts of Ruby code with it.

markus