From: Kent Dahl <kentda+news@...>
Date: 2003-09-18T00:16:23+09:00
Subject: Re: Nested class/module namespace

Nathaniel Talbott wrote:
> In many cases this form of nesting will create more typing for me than the
> normal form of nesting! 

Yes, in particular something like these three lines:

module Constants
end
include Fully::Qualified::ModuleName::Constants

....where the last line may be repeated. This is a cleaner separation of 
namespaces anyway. The constants ultimately belong inside the classes 
that use them, not in some arbitrary common ancestral namespace area 
which saves you typing.

> OTOH, I haven't ever had trouble with too much
> namespace exposure except with top-level classes (like Queue) that cause
> confusion when I forget to require something and they magically get used
> instead of my classes without an (immediate) error. But this new form
> doesn't solve that problem, so I don't see any benefit in how it behaves.
> Can you give an example where this is beneficial?

Replace top-level classes with constants (i.e. classes, constant 
variables, modules etc) anywhere within the module hierachy, and you 
have one example.

Granted, the average Ruby program isn't of such a size that this becomes 
  much of an issue, but once someone writes a 10kLOC killer app in Ruby, 
they will be thankful for proper namespace functionality.

If we can pop over to C++ land for a short while, the "module M;class 
C;end;end" style opens a namespace scheme that is akin to "#include 
<m.h>" within c.h. The new style "class M::C;include M::Constants;end" 
has more in common with C++ "using namespace m;". The latter is better 
in the long run; only take in what you are sure you need.

-- 
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