From: Xavier Noria <fxn@...>
Date: 2007-11-15T05:41:21+09:00
Subject: Re: Module#constants

On Nov 14, 2007, at 6:36 PM, ara.t.howard wrote:

>
> On Nov 14, 2007, at 5:44 AM, Xavier Noria wrote:
>
>> Why is M::C in scope there?
>
> for the same reason that File and Object are.  imagine if C were  
> not, then we would have to write
>
>  ::File.open path
>
> whenever opening a File.
>
> the scope crawls up the nesting.

Thank you! I had once that hypothesis but this example broke it:

   module M
     C = 1
     module N
     end
   end

   M::N.module_eval do
     File  # -> OK
     C     # -> NameError
   end

File is seen but C is not. So I think there's something more into it.  
The best conjecture I have by now is that you need to have the  
enclosing module syntactically there with the nested "module/class"s.

However, I have seen that even if there something syntactic the name  
of the constant is not used, I mean this works:

   module M
     C = 1
     module N
     end
   end

   X = M
   module X
     module N
       C
     end
   end

That makes some sense because if X is already a module that module is  
reponed, fine, but all the examples together give kind of a mix of  
runtime and syntatic things to take into account.

I don't yet understand the complete rule.

-- fxn