From: Brian Candler <b.candler@...>
Date: 2009-08-25T22:11:38+09:00
Subject: Re: Packaging - distribution

Pito Salas wrote:
> David,
> 
> Thanks for a sensational answer to my question! Great detail, very 
> informative.
> 
>> $: << '/path/to/system/lib'
>> require 'sub_alpha'
>> 
>> In my opinion, that's much better than trying to do something like:
>> 
>> require '/path/to/system/lib/sub_alpha.rb'
> 
> I've seen the $: << construct; can you say a little about why it's much 
> better than putting the path directly in the require?
> 
> My guess is that the path appears only once in the $: line so if it 
> changes you don't have to go changing a whole bunch of requires. Yes, or 
> is there something else more important?

If one bit of code does "require 'sub_alpha'", and another bit of code 
does "require '/path/to/system/lib/sub_alpha'", then the file will be 
loaded twice.

So you may see this pattern:

  require File.dirname(__FILE__)+"/../lib/sub_alpha"

but I'd strongly recommend against it.

BTW, $:.unshift is probably better than $: <<, because it will put your 
code at the front of the path.
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