From: "Benjamin J. Tilly" <ben_tilly@...>
Date: 2001-04-22T01:01:07+09:00
Subject: [ruby-talk:13984] RCR, strange things in $:

I decided to catch up on old summaries of p5p, and I ran
across a description of how (in Perl) you will be able to
play games like reading a module from a zip file:

http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2001-02/msg01780.html

Well that is a little convoluted, but since Ruby's $: is
a relative of Perl's @INC, I have to wonder whether
something like this is possible for Ruby.  But of course
simpler, better designed.

So here is the request.

$: should allow objects to be placed in it.  Whenever
Ruby goes to search for a module it should check for
whether a method named something like, "find_file"
is implemented.  If it isn't, then act as it does now.
If it is, then call the method with the name of the
file you are searching $: for.  It should return
either nil (not found) or an object matching a
specified subset of the API for objects of class IO.

Example uses:

1. Allow modules to be loaded from a zip archive.
2. Allow modules that are transparently installed upon
   first use from a remote repository.
3. Allow modules to be run through a preprocessor before
   loading.

In fact (more thought would have to go into this) why
not add a method to File::Open which takes 2 arguments,
and returns a filehandle for read, and then have Ruby
call that when it loads from $:?  That would allow the
same API that I am suggesting for modules to also be
used inside of Ruby as well...

Cheers,
Ben