Re: [Scheme-reports] multiple values module xacc.ide@gmail.com (20 May 2011 20:07 UTC)
Re: [Scheme-reports] multiple values module Peter Bex (22 May 2011 16:49 UTC)
Re: [Scheme-reports] multiple values module Alaric Snell-Pym (23 May 2011 11:49 UTC)
Re: [Scheme-reports] multiple values module Aaron W. Hsu (23 May 2011 22:05 UTC)

Re: [Scheme-reports] multiple values module Aaron W. Hsu 23 May 2011 21:58 UTC

On Mon, 23 May 2011 07:45:26 -0400, Alaric Snell-Pym
<alaric@snell-pym.org.uk> wrote:

> On 05/22/11 17:43, Peter Bex wrote:
>
>> This behaviour is quite practical and even enables a new idiom;
>> procedures can return one "main" value and several additional values
>> that you might sometimes need.  Then you can just call the procedure
>> as if it returned one value when you don't need the extra info.
>
> I like this idiom, too.

I might note, however, that his sort of idiom, is far different than the
Chibi behavior. The abstraction of multiple values is not lost, because
the multiple values are not reified. Chibi reifies multiple values into
something that one cannot distinguish from a list, and that is, IMO, a bad
thing. If reification happens, then it should be as a distinct type, and
not as a tagged list.

I'm fine with the standard being lax on this point, and I think even the
more "specified" R6RS left multiple values fairly open, but I do not think
it would be a bad thing to specify a few things to keep up abstraction
barriers. Maybe I'm missing something big here?

	Aaron W. Hsu

--
Programming is just another word for the lost art of thinking.

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