From: Laurent Sansonetti <laurent@...>
Date: 2003-06-19T00:16:25+09:00
Subject: Re: Categories like in Objective-C

Hello Stefan,

Stefan Arentz wrote:

> Hola,
> 
> Objective-C has categories. They allow you to extend a class like this:
> 
>  @interface NSArray (ArrayAdditions)
>   - (void) randomize;
>  @end
> 
>  @implementation NSArray (ArrayAdditions)
>   - (void) randomize {
>     ... this executes as if it is a method of NSArray ...
>   }
>  @end
> 
> This example adds a randomize method to the existing NSArray class.
> 
> The Category is active the moment it is loaded into the runtime.
> 
> Is this also possible in Ruby? I know about Class.extend and Mixins, but what I
> am looking for is the auto-loading.
> 
>  S.
> 
> 

class Array
   def randomize
     # insert your code here
   end
end

a = Array.new
a.randomize

;-)

Hope that helps,

-- 
Laurent