From: Trans <transfire@...>
Date: 2006-08-09T04:45:45+09:00
Subject: Re: load paths unions?


Robert Klemme wrote:
> On 08.08.2006 18:06, Trans wrote:
> > I want to be able to "union" some load paths. Eg. given
> >
> >   lib/facets/more
> >   lib/facets/core
> >
> > I'd like to be able to do
> >
> >   require 'facets/foo.rb'
> >
> > And have it search both more/ and core/ for foo.rb.
>
> Usually you do
>
> require 'facets/foo'
>
> and have a file "xyz.rb" in facets that will link "more/foo.rb" or
> "core/foo.rb" depending on where it's located.

Yes, currently I a separate directory facet/ that I build automatically
which contains nothing but require redirections: Eg. facet/foo.rb
contains "require 'facets/core/foo.rb'". But there are a lot of files
and I find it rather wasteful solution --at tlease two requires for
every one. Plus I have to use a slighly different name -- 'facet'
instead of 'facets'.

> You could as well do this: create a file "facets.rb" in the same
> directory that holds "facets" (i.e. lib).  Inside of that you do
>
> def frequire(*names)
>    names.each do |name|
>      %w{more core}.any? do |base|
>        begin
>          require "facets/#{base}/#{name}"
>          true
>        rescue
>          false
>        end
>      end or raise LoadError, "Did not find #{name}"
>    end
> end

I don't want a seprate method, but I have consieder overriding
#require. I just hoping there might be a better clever way. I hear
Python supports .pth files which can redirect whole path reference to
anther location. I wonder if Ruby could support something like this?

T.