From: Jim Weirich <jim@...>
Date: 2005-08-12T14:33:11+09:00
Subject: Re: [ANN] LibInject 0.1.0: Small Pieces Smooshed Together

On Thursday 11 August 2005 11:31 pm, Francis Hwang wrote:
> I've just released the first version of LibInject, which is a developer
> tool for injecting external dependencies into a Ruby file. More
> specifically, it finds require statements that point to files that
> aren't in the standard library, expands those files, and drops the raw
> text into the original file.
>
> http://libinject.rubyforge.org/
>
> Why would somebody do this instead of just using a plain old require
> statement? One reason might be because you want to write a one-file
> script that can also have external dependencies. I wrote LibInject for
> use with FeedBlender, which is intended as a one-file script aimed at
> Ruby newbies who might not even know how to install from .tar.gz files
> or from RubyGems. With LibInject, I can have external dependencies in
> FeedBlender, use a Rake task to inject those libraries into
> feedblender.rb, and then distribute the end result.
>
> For example, let's say you've three files, a.rb, b.rb, and c.rb. a.rb
> requires b.rb and c.rb, and b.rb requires c.rb:
>
> a.rb:
>
>   require 'b'
>   require 'c'
>
>   class A; end
>
> b.rb:
>
>   require 'c'
>
>   class B; end
>
> c.rb:
>
>   class C; end
>
> If you wanted to distribute a version of a.rb without any external
> dependencies, this is how you'd run LibInject:
>
>   require 'libinject'
>
>   puts LibInject.lib_inject( File.open( 'a.rb' ) )
>
>   # We could also pass LibInject.lib_inject a String, like so:
>   #   contents = File.open( 'a.rb' ) do |f| f.gets( nil ); end
>   #   puts LibInject.lib_inject( contents )
>
> And this is what you'll get:
>
>   #
> v---------v---------v---------v---------v---------v---------v---------v
>   # LibInject: begin 'b' library injection
>   #
> v---------v---------v---------v---------v---------v---------v---------v
>
>
>   #
> v---------v---------v---------v---------v---------v---------v---------v
>   # LibInject: begin 'c' library injection
>   #
> v---------v---------v---------v---------v---------v---------v---------v
>
>   class C; end
>
>   #
> ^---------^---------^---------^---------^---------^---------^---------^
>   # LibInject: end 'c' library injection
>   #
> ^---------^---------^---------^---------^---------^---------^---------^
>
>
>   class B; end
>
>   #
> ^---------^---------^---------^---------^---------^---------^---------^
>   # LibInject: end 'b' library injection
>   #
> ^---------^---------^---------^---------^---------^---------^---------^
>
>
>
>   class A; end
>
> The code looks sort of messy, but now it's all in one file.
>
> Anyway, it's a strange little script, and I'm curious as to whether
> anybody else will get some use out of it. Let me know if you do!
>
> F.

Cool!  Does it handle things like this:

  class Command
    def create_option_parser
      require 'optparse'
      @parser = OptionParser.new
      ...
    end
  end

-- 
-- Jim Weirich    jim@weirichhouse.org     http://onestepback.org
-----------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct, 
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)