From: Pit Capitain <pit.capitain@...>
Date: 2008-08-18T16:25:45+09:00
Subject: Re: def .. end is ok and class .. end is not ok .. Why??

2008/8/18 Kyung won Cheon <kdream95@gmerce.co.kr>:
> module M
> end
>
> M.module_eval { def self.a; puts 'ok' end }
> M.a
> # => 'ok'
>
> M.module_eval { class A; end }
> M::A
>
> # => uninitialized constant M::A (NameError)

Constants (including class and module names) are lexically scoped (at
least in Ruby 1.8). Your code therefore defines the top-level class A.
If you want a nested constant, you could do

  M.module_eval { class self::A; end }

Regards,
Pit