From: Sam Smoot <ssmoot@...>
Date: 2007-12-30T00:50:00+09:00
Subject: Re: def if ; end - basically impossible?

On Dec 28, 10:57 pm, Giles Bowkett <gil...@gmail.com> wrote:
> > > Generator.module_eval(&block)
>
> > If you're passing the code as a block, the easiest solution may be
> > ParseTree? I haven't toyed with it, but Ryan Davis also just released
> > ruby_parser apparently, which seems to be a pure-ruby version of
> > ParseTree.
>
> I think that's correct; it's either a Ruby port or a Ruby equivalent.
> But it returns s-exps; what I really need is to catch ifs and send
> them to an if method.


Right. I guess I meant it would seem like you could use ParseTree (or
something similar) to detect if/elsif/else/end constructs, and then re-
evaluate their interiors as a new proc (I *think* ParseTree can
compile a S-Exp to Ruby, but I haven't tried that side personally).
That way, you could evaluate the condition, and then send the correct
branch along.

I guess my assumption is that you don't necessarily *need* to have a
method called :if if you can properly detect/handle `if` keywords in
the blocks. But that assumption could be off base. Maybe your whole
point is building a DSL with :if methods to use. I dunno. Best of
luck. :-)