From: Austin Ziegler <austin@...>
Date: 2004-02-26T00:56:18+09:00
Subject: Re: Operators +, += and = in Ruby 2

On Thu, 26 Feb 2004 00:14:50 +0900, Robert Klemme wrote:
> Operator += can't be user defined but instead is extended to a
> combination of "+" and assignment: "x += y" becomes implicitely "x = x +
> y".

> Now, wouldn't it be better to turn that around and have people define
> operator += and automatically convert operator + like in:

> "x + y" becomes implicitely "x.dup += y"

> The reason I'm offering this is performance: "x = x + y" is slower than
> an inplace manipulation (that += would do), which is often what's desired
> here.

Better to have a new method for this:

x.add(y)

The problem is that assignment works on variables, but + is a method call
on an object. Ruby is the only language that I know that has such a 
distinction, but it's one that (to me) makes perfect sense.

-austin
--
austin ziegler    * austin@halostatue.ca * Toronto, ON, Canada
software designer * pragmatic programmer * 2004.02.25
                                         * 10.55.34