From: Austin Ziegler <halostatue@...>
Date: 2005-01-20T06:37:15+09:00
Subject: Re: is defined? fast?

On Thu, 20 Jan 2005 05:52:59 +0900, Bill Kelly <billk@cts.com> wrote:
> From: "Austin Ziegler" <halostatue@gmail.com > 
>> unless defined?(Text)
>>   module Text; end
>> end
>> 
>> class Text::Format
>>   ...
>> end
>> 
>> Saves me some indentation levels and keeps the code readable and working.
> Is the top part semantically different from just,
> 
> module Text; end
> 
> ?


  irb(main):001:0> class Text; end
  => nil
  irb(main):002:0> module Text; end
  TypeError: Text is not a module
          from (irb):2
  irb(main):003:0>

It's simply defensive programming.

I could shorten it with:

  module Text; end unless defined?(Text)

I haven't done this with all of my libraries, but mostly on those
libraries where I am using the module as a namespace (e.g.,
Text::Format, Text::Hyphen, and now Kaspar's Text::Reform).

It's not perfect, but it's better than it could be ;)

-austin
-- 
Austin Ziegler * halostatue@gmail.com
               * Alternate: austin@halostatue.ca