From: Tony Arcieri <tony@...>
Date: 2010-02-09T04:30:15+09:00
Subject: Re: Why no ++ and --?

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On Mon, Feb 8, 2010 at 12:20 PM, Seebs <usenet-nospam@seebs.net> wrote:

> You can't increment the underlying object, because fixnums are immutable.
>

Not to beat the dead horse any more but...

In a language like Ruby where the binding operates entirely by reference, it
would only make sense for the ++ operator to change which object a variable
name references (i.e. destructive assignment) as opposed to sending a
message which actually mutates the object it references, especially since ++
is an operator intended to work with numbers and Ruby's numbers are
immutable.

Using x++ as a shorthand for:

   begin; _tmp = x; x += 1; _tmp; end

...would be the only sensible implementation.

There exists an operator in Ruby which doesn't send a message: =.  The "="
operator modifies the binding.  ++ (and --) would have to do the same.

Unprecedented?  Yes.  But not impossible.

-- 
Tony Arcieri
Medioh! A Kudelski Brand

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