From: Austin Ziegler <austin@...>
Date: 2002-09-11T03:11:10+09:00
Subject: Re: Larry Wall's comments on Ruby

On Tue, 10 Sep 2002 23:31:40 +0900, nico wrote:
> On September 10, 2002 04:38 am, Gavin Sinclair wrote:
>> I'm not convinced that it's unnatural. We don't know the types of
>> a and b, and for some objects a and b, a + b != b + a.
>> 
>> I'm interested what you think the alternative is, or an argument
>> against the above, and how you would like to see a + b defined in
>> Ruby.
> I find that highly unnatural because we've been learning since
> grade school that a + b = b + a.
> 
> If the objects don't satisfy that property they should be using a
> different symbol.

Ummm... with a string, a + b != b + a; yet this is to be expected. I
did a quick Google on "non-commutative addition" and came up with

http://www.cut-the-knot.com/do_you_know/addition.shtml

This says that addition is *often* required to be commutative, but
not always.

-austin
-- Austin Ziegler, austin@halostatue.ca on 2002.09.10 at 14.02.11