From: Christoph Rippel <chjr@...>
Date: 2001-06-16T19:27:14+09:00
Subject: [ruby-talk:16534] Re: why only nil and false are regarded as false?

> From: dave@thomases.com [mailto:dave@thomases.com]On Behalf Of Dave
...
> Do you have some examples where you'd like other values to be false?

Well I do have an example for this,  

a while back I outlined a ``logical Infinity module''[ruby-talk:13469] 
which adds two visible ``+/- Infinity constants'' (instanced with
Infinity.plus and Infinity.minus) to the Numeric hierarchy.  The basic
idea is to delegate ``if-then-else'' constructs which handle  
``extremal states'' from regular program flow to the Infinity Class 
itself - the most obvious are examples are the min/max values for empty 
Enumerable - with  the 1.7 version you can write 

require 'infinity'
module Enumerable
	Minus= Infinity.minus
	def max; inject(Minus) {|a,b| (a > b ) ? a : b } end
end
end

In most situation the ``correct logical value'' of Infinity.minus should
be false - without a fundamental language change one can achieve this
effect by adding  a ``to truth'' method  to Object ... 


Christoph




Ideally one would evaluated the Infinity instances 



> 
> Dave
>