From: Clifford Heath <no@...>
Date: 2008-08-05T12:58:36+09:00
Subject: Re: State of the Onion

David Masover wrote:
> Has anyone actually done the equivalent of Acme::Lingua::Pirate::Perl for 
> Ruby? If so, how much work was it? How hackish was it?

I'm not familiar with Acme::..., but the right answer for Ruby
is to use a composable grammar for its compiler (such as, but
not necessarily, the ones emitted by Treetop), and then to
simply support the "grammar" block ala Treetop where you can
define new syntax rules. Any time a new grammar rule fires,
the syntax may include as much or as little of the general
Ruby syntax as the rules decide to call. When a grammar rule
replaces a built-in one, it's able to use "super" to call the
original rule, as in Treetop... If you can also associate a
grammar rule as thej top rule of a filetype extension for a
file loaded from require (the way my Polyglot gem does), you
can require files in any language for which you have a grammar.

This is an amazingly powerful concept... someone will do it
sooner or later.

Clifford Heath.