Marc Nieper-Wißkirchen <xxxxxx@nieper-wisskirchen.de> writes:

>> Can I re-order multiple values?
>> -------------------------------
>>
>> I can think of quite a few reasons for using re-ordering. Did I miss
>> this is the discussion?
>>
>
> I think it is hard to find a good syntax for it that is implementable just
> with syntax-rules.

Ah, I remember. That was the discussion about making this generic. I
didn’t quite understand why that’s essential: If there are more than 10
values, the added overhead of λ(_ ...) wouldn’t hurt much, but when you
have just 3 values, the relative impact of the required λ is much
bigger.

So why not enable elegant simple cases with _ _0 _1 _2 _3 _4 _5 _6 _7 _8
and _9 (making _0 a synonym for _)?

>> chain (floor/ 3 2) (fraction-of-the-rest _ _) ?

chain (floor/ 3 2) (fraction-of-the-rest _1 _0)

>> Why doesn’t chain-and support multiple values?
>> ----------------------------------------------
>>
>> It could use the first value as control-value. If the first value is #f,
>> the chain ends.
>>
>
> That would have very special semantics. Just taking the first value is
> rather arbitrary and the case of zero values wouldn't fit into this model
> as well.

I thought about just using the first value, because that is the value
you would receive when calling the procedure without handling of
multiple values.

I didn’t think of zero values in this, though. That could never be #f
then.

Best wishes,
Arne
--
Unpolitisch sein
heißt politisch sein
ohne es zu merken