[Ur] last type decl wins?
Adam Chlipala
adamc at impredicative.com
Sat Apr 16 13:04:19 EDT 2011
Marc Weber wrote:
> Excerpts from Adam Chlipala's message of Sat Apr 16 17:21:39 +0200 2011:
>
>> I think of almost every Haskell program as an "incomprehensible
>> entangled mess," because of implicit mutual recursion spread across
>> files!
>>
> You're talking about this, correct?
>
> a = b
>
> b = a
>
> without a "and" ?
>
Yes, that's an example of implicit mutual recursion. Vag's follow-up
example is even worse, because the "recursion" is entirely accidental.
> I don't expect there being a perfect way at all.
>
Indeed. I propose restricting further discussion of this issue to
empirical results with reasonable scientific validity. (That should
keep anyone busy for a while! :D)
> May I conclude from that that urweb should support overloading? :)
It does, with type classes, just as in Haskell.
> Do you have some specific function names in mind which share a name but
> have slightly different behaviour?
>
> would map and queryX be such cases?
>
I would say these deserve to be distinguished, because the latter
requires side effects, while the former does not.
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