Call to arms: lambda-case is stuck and needs your help

Mikhail Vorozhtsov mikhail.vorozhtsov at gmail.com
Mon Jul 9 16:04:56 CEST 2012


Hi Simon.

On 07/09/2012 08:23 PM, Simon Marlow wrote:
> On 07/07/2012 16:07, Strake wrote:
>> On 07/07/2012, Jonas Almström Duregård <jonas.duregard at chalmers.se>
>> wrote:
>>> Couldn't we use \\ for multi-case lambdas with layout?
>>>
>>> If not, these are my preferences in order (all are single argument
>>> versions):
>>> 1: Omission: "case of". There seems to be some support for this but it
>>> was not included in the summary.
>>> 2: Omission with clarification: "\case of"
>>> 3: "\of"  - but I think this is a little weird. It's nice to have
>>> short keywords but not at the expense of intuition. The goal here is
>>> to drop the variable name not the case keyword, right?
>>>
>>> Regards,
>>> Jonas
>>
>> Well, since this is now suddenly a ranked-choice election, I shall
>> re-cast my vote:
>
> I think some misunderstanding has crept in - we're not planning to count
> votes or anything here.  If you have new suggestions or know of reasons
> for/against existing proposals then please post, otherwise there's no
> need to post just to express your personal preference.
Could you express your opinion on the case "comma sugar", i.e.

case x, y of
   P1, P2 -> ...
   P3, P4 -> ...

as sugar for

case (# x, y #) of
   (# P1, P2 #) -> ...
   (# P3, P4 #) -> ...

and respectively

\case
   P1, P2 -> ...
   P3, P4 -> ...

as sugar for

\x y -> case x, y of
   P1, P2 -> ...
   P3, P4 -> ...

?



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