From: Robert Klemme <bob.news@...>
Date: 2004-12-29T17:56:46+09:00
Subject: Re: Namespaces, inverted


"E S" <eero.saynatkari@kolumbus.fi> schrieb im Newsbeitrag
news:20041228221857.GQPI5992.fep32-app.kolumbus.fi@mta.imail.kolumbus.fi...
> > L�hett�j�: "Robert Klemme" <bob.news@gmx.net>
> > "Joel VanderWerf" <vjoel@PATH.Berkeley.EDU> schrieb im Newsbeitrag
> > news:41D0E5EF.1040308@path.berkeley.edu...
> > > eero.saynatkari@kolumbus.fi wrote:
> > > [Snip]
>
> > > class String
> > >  def as mod
> > >   {:name => self, :module => mod}
> > >  end
> > > end
>
> > I don't like the idea of the as method as it cannot be used reasonable
in
> > other circumstances as module loading.  The code really does not
belong into
> > class String IMHO.
>
> Agreed. It just looked better :) I suppose a top-level method
> would have done as nicely for this how-it-can-be-done-now
> implementation.
>
> > We have Kernel#load [1] with a similar functionality already.
Currently it
> > accepts an additional parameter to enforce wrapping of the file in an
> > anonymous module.  That could be extended to accept a module as well;
that
> > then would be the module used.  Then we can do
> >
> > load "foo.rb" # not wrapped
> > load "foo.rb" # wrapped in an anonymous module
> > load "foo.rb", MyExternal # wrapped in MyExternal
>
> Good. I had to rely on a 1.6 reference knowledge and didn't
> recall the second parameter. Implementing it this way would,
> certainly, require a change at the core level so an RCR might
> be appropriate. I can write it up, I suppose.

Great!

> I'm still partial to 'import' vs. 'require', though :)

Well, I'm open there.  It's just that load and require have established
semantics: "load" reads the file on every occurrence while "require" loads
it only once (plus it does some file name magice to determine whether it's
"foo.rb", or "foo.so" / "foo.dll").

> > Additionally / Alternatively it could be useful to have a per module
require
> > like this:
> >
> > class Module
> >   def require(*files)
> >     # puts "loading in module #{self}: #{files.inspect}"
> >     @loaded ||= {}
> >     files.each do |f|
> >       unless @loaded[f]
> >         # real load code that wraps contents of f in self
> >         @loaded[f] = true
> >       end
> >     end
> >   end
> > end
> >
> > Then we could do
> >
> > module Foo
> >   require "bar"
> > end
> >
> > and even if we do the same later again, "bar" is only loaded once (see
[2]).
>
> Looks nice, although the functionality is somewhat
> overlapping, no?

Yes, that's why I wrote "Additionally / Alternatively". :-)  But keep in
mind the difference between load once and load always.

Regards

    robert