Drastic Prelude changes imminent
Erik Hesselink
hesselink at gmail.com
Tue Jan 27 16:15:06 UTC 2015
I don't see why from your email, but my only point was that having
both polymorphic versions of functions in the Prelude, and monomorphic
ones in Data.List, will probably be worse than either of the other two
options (the fully polymorphic version being prepared, and the status
quo you want to keep).
Erik
On Tue, Jan 27, 2015 at 5:10 PM, Augustsson, Lennart
<Lennart.Augustsson at sc.com> wrote:
> But having Data.List export a non-list version of foldr is a terrible idea.
>
> -----Original Message-----
> From: Erik Hesselink [mailto:hesselink at gmail.com]
> Sent: 27 January 2015 16:07
> To: Johan Tibell
> Cc: Augustsson, Lennart; libraries at haskell.org
> Subject: Re: Drastic Prelude changes imminent
>
> That doesn't really sound feasible, as there would be name clashes when importing both the Prelude (with generalized functions) and Data.List (with monomorphic functions). The only way to get generalized functions and minimize breakage is to also generalize Data.List.
>
> Erik
>
> On Tue, Jan 27, 2015 at 5:03 PM, Johan Tibell <johan.tibell at gmail.com> wrote:
>> Looking at the generalizations in Data.List I find them pretty odd now
>> when I think about it. I'd expect Data.List functions to be
>> monomorphic to lists, just like I expect functions in Data.Map to be
>> monomorphic to maps. Now there might be generalized versions of these
>> functions in e.g. the Prelude, but generalizing Data.List means that I
>> don't even have the monomorphic versions available if I want to resolve ambiguity by using them*.
>>
>> * It turns out resolving ambiguity is pretty annoying. The type
>> signatures are awkward to write so I end having to write something
>> akin to
>>
>> mymap :: (a -> b) -> [a] -> [b]
>> mymap = map
>>
>>
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