From: Robert Klemme <bob.news@...>
Date: 2004-07-26T22:16:53+09:00
Subject: Re: code introspection


"Lothar Scholz" <mailinglists@scriptolutions.com> schrieb im Newsbeitrag
news:178359988968.20040726131022@scriptolutions.com...
> Hello Daniel,
>
> DC> Is there a solution to do code introspection rather than
introspection
> DC> at the level of the Module/Object ? I can't figure out if I'm
looking
>
> Yes but only from the C level. You need to create the "Node" tree and
> travere it. Unfortuneatly there seems to be no visitor pattern class to
do
> this and you must expect that the Node structure can change even
> between minor updates a lot. So read the code in eval.c and parse.c.

Err, I think this is overkill.  Daniel just wants to create an instance of
a class whose name he knows.  So the already suggested Object.const_get(
class_name ) or ObjectSpace.const_get( class_name ) suffices.

If you don't know class names beforehand, you can work with an anonymous
module as wrapper like this:

mod = Module.new
mod.class_eval( File.read( "foo.rb" ) )
new_classes = mod.constants.inject([]) {|ar,c| cl=mod.const_get(c); ar <<
cl if Class === cl; ar}
p new_classes
include mod
p Foo

Or even do this

mod = Object
mod.class_eval( File.read( "foo.rb" ) )
classes = mod.constants.inject([]) {|ar,c| cl=mod.const_get(c); ar << cl
if Class === cl; ar}
p classes
p Foo


Regards

    robert