From: Robert Klemme <shortcutter@...>
Date: 2010-01-12T16:15:12+09:00
Subject: Re: A.module_eval question

On 11.01.2010 21:42, Aryk Grosz wrote:
> I'm having trouble understanding why this is:
> 
> module A
> module B
> end
> end
> 
> A.module_eval "B" -> A::B
> A.module_eval do B end -> ERROR!
> A.module_eval do self::B end => A::B
> 
> Why does the second one error out? If its actually being evaluated
> within the scope of the module, it should work...no?
> 
> 
> Could someone explain this to me. Is there a trick I'm not doing?

What version of Ruby did you use?  IIRC in 1.8 versions the lookup of 
the constant was statically scoped so - since there is no B around - you 
get an error.  With the other approaches you explicitly start the lookup 
at module A.  We had a recent discussion about this where I collected 
some links about the topic:

http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/354034

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/