From: "David A. Black" <dblack@...>
Date: 2005-07-31T01:33:10+09:00
Subject: Re: make local var visible

Hi --

On Sun, 31 Jul 2005, Trans wrote:

> Hmm... I just ran into a problem with constant lookup (namely
> class/module lookup). I wrote an autoloader, such that of
> #const_missing it will try to find the class or module in a file and
> require it. Unfortuately, for it to work I ALWAYS has to use '::'
> before the class/module name. I know what the problem and how to fix
> --I need to work upward through each namespace to see if it's there.
> But that got me thinking about what botp has asked.
>
> First I wondered what this could be meaningful:
>
>  foo = [ "a","b","c" ]
>
>  def mfoo
>    ::foo.each do |f|
>    p f
>  end
>
>  mfoo
>
> Then wondered too if variable lookup could proceed in a manner like
> constant lookup. If you don't find it in the current scope, then try
> the next one up, and so on. local -> instance -> class -> module
> namespaces -> ... -> top/global. (hmm..That's how block scopes seem to
> work too, now that I think of it.)
>
> I must be over looking something though, it seems too straight foward
> ;-)

That would essentially do away with the notion of a local variable.  I
think it's valuable to have them -- really quarantined "scratchpad"
things that just don't overlap between scopes.  Writing things that
depend on local variable names from other scopes is pretty fragile.


David

-- 
David A. Black
dblack@wobblini.net