From: ptkwt@... (Phil Tomson)
Date: 2006-02-09T11:13:22+09:00
Subject: Re: distributing native and ruby version of a library

In article <m2zml162to.fsf@levana.de>,
Patrick Gundlach  <clr8.10.randomuser@spamgourmet.com> wrote:
>Hi,
>
>I have a simple library, one in a pure ruby version and one in a
>ruby/c version (which is quicker). I would like to distribute both and
>let the user decide (by checking whether a c library is available)
>which version to install. What would a clever way to accomplish that?
>Should I make the decision when running extconf.rb? Any hints?
>
>Patrick
>
>(the directory structure so far)
>
>rb/mylib.rb
>
>c/mylib.rb
> /mylib_base.c
> /extconf.rb
>
>both should be used by require 'mylib' or alike.
>


How about in your rb/mylib.rb file you do something like:

  begin
    require 'ext/mylib_base' 
  rescue
    require 'lib/mylib_base'
  end

Where ext/mylib_base would be the shared lib created from the C file and 
lib/mylib_base would be the Ruby implementation.

The user of mylib just does:

  require 'mylib'

....and it's all transparent to the user whether or not the C version or the 
ruby version is used.

Phil