From: Robert Klemme <shortcutter@...>
Date: 2011-02-03T18:48:38+09:00
Subject: Re: Amazing behavior of include module

On Thu, Feb 3, 2011 at 5:01 AM, Andrew Wagner <wagner.andrew@gmail.com> wrote:
>>
>> Including AAA at the top level, as in line 7, acts the same as including it
>>  on Object, so every object suddenly has BBB available to it.
>
> This explanation makes sense, and certainly fits the facts. But why is doing
> 'include' from an irb prompt the same as including the module in Object? If
> self points to main, and main is an instance of Object, shouldn't the module
> get included into main's eigenclass?

I believe IRB mimics behavior of the Ruby interpreter here:

10:44:58 ~$ ruby19 <<CODE
> module A; class B; end; end
> include A
> p B
> p Fixnum::B
> CODE
A::B
A::B
10:45:32 ~$ ruby19 -e 'p self'
main
10:45:51 ~$ irb19
Ruby version 1.9.2
irb(main):001:0> self
=> main

Reasoning behind this is certainly is that this way namespaces work as
expected.  If only main would get access to the inclusion, you could
not use a constant nested in your included module in *any* other
class.

Personally I don't like including at top level that much because it
always includes the risk of name clashes.  I usually do this only in
small or one off scripts.

Kind regards

robert


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