From: Alex Young <alex@...>
Date: 2006-07-22T22:01:51+09:00
Subject: Re: Assigning blame?

Ben Zealley wrote:
> 'allo
> 
> Say I have two classes:
> 
> class Bloke
> 	attr_reader :name
> 	def sellSoul(aDemon)
> 		aDemon.buySoul(self)
> 	end
> end
> 
> class Demon
> 	def buySoul(aBloke)
> 		# if aBloke called the method, OK. Else, tell them where to go.
> 		puts("I bought #{aBloke.name}'s soul!")
> 	end
> end
> 
> Tim = Bloke.new
> Tim.name = "Tim"
> Satan = Demon.new
> Tim.sellSoul(Satan)
> 
> I would like the buySoul method to work only if the Bloke calling it is
> the same instance of Bloke named, but I can't find any way to determine
> what object called a given method. Does anyone have a suggestion?
Not quite what you're after, but it has the same effect:  make sellSoul 
a private method, so that it's only possible (without #send contortions) 
for Tim to call sellSoul on self.

Other than that, I think you'll be into checking object_ids against 
constants at the top execution level, which isn't particularly useful. 
You could pass the binding to buySoul, I guess, but that's just as nasty.

-- 
Alex