[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Scheme-reports] multiple values module
Emmanuel Medernach scripsit:
> Except for continuations created by the call-with-values procedure,
> all continuations take exactly one value. The effect of passing no
> value or more than one value to continuations that were not created
> by call-with-values is unspecified.
>
> Therefore code relying on this cannot be portable, isn't it ?
No, it's not portable.
> As you say, some implementation reifies 'values'. However the
> R[567]RS definition of values currently forbids to reify it as I
> understand it :
>
> (values obj ...) procedure Delivers all of its arguments to its
> continuation.
It doesn't say *how* they are delivered. Reification is a perfectly
legitimate strategy. Historically, multiple values were intended to be
a more lightweight alternative to constructing an object:
--
Where the wombat has walked, John Cowan <cowan@x>
it will inevitably walk again. http://www.ccil.org/~cowan
_______________________________________________
Scheme-reports mailing list
Scheme-reports@x
http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports