From: Dossy <dossy@...>
Date: 2002-07-17T02:00:31+09:00
Subject: Re: TkText no -textvariable workaround?

On 2002.07.17, Tom Sawyer <transami@transami.net> wrote:
> actually, Dossy, your post was a bit helpful. what i'm after also sort
> of relates to the observer pattern. but in attempting to get ruby to
> help me out with this i've stumbled upon an interesting question in its
> own right (IMHO):
> 
> in this simple example:
> 
>   a = 1
> 
> who is the receiver and what is the method? ...*long pause*...

Speaking academically, the receiver is object a, the method is =(x).

Ruby may have optimized some of this away, but it's essentially the
idea.

Sadly, you can't do this:

irb(main):011:0> class Object
irb(main):012:1>   def =(x)
irb(main):013:2>     puts "You just set me to #{x}!"
irb(main):014:2>   end
irb(main):015:1> end
SyntaxError: compile error
(irb):12: parse error
  def =(x)
       ^
(irb):15: parse error
        from (irb):15

Since I'm dumb, there's probably a really good reason for
this but I can't think of it -- I just ate a ham and provolone
sandwich.

> i wondered this b/c i had the bright idea that i'd just modify the
> Object class with an obverser pattern of sorts, to solve my problem,
> but, well obviously that didn't go as planned and hence this question.

Look at Test::Unit -- Nathaniel has nicely implemented the Observer
pattern in Ruby.

-- Dossy

-- 
Dossy Shiobara                       mail: dossy@panoptic.com 
Panoptic Computer Network             web: http://www.panoptic.com/ 
  "He realized the fastest way to change is to laugh at your own
    folly -- then you can let go and quickly move on." (p. 70)