From: "David A. Black" <dblack@...>
Date: 2004-12-09T04:51:21+09:00
Subject: Re: Overloading a module method?

Hi --

On Thu, 9 Dec 2004, Dominik Werder wrote:

> I'm having a headache while trying to achive something like this:
>
> module Math
>  def Math.cos val
>    if val.kind_of? MyType
>      val = super(val)
>      # do stuff with val and return
>      return val
>    else
>      # normal behavior
>      super
>    end
>  end
> end
>
> super seems not to work, perhaps because Math is not a module..
>
> Does anybody please know how to to this?

I think what you want is to alias the old method.  super takes you up
the method lookup chain, whereas alias operates at the same level but
moves laterally, so to speak.

   class << Math   # operate on Math's singleton superclass
     alias :oldcos :cos
     def cos(val)
       # here, oldcos(val) will call the old cos

etc.


David

-- 
David A. Black
dblack@wobblini.net