Add `take`/`drop`/`splitAt` to `Data.Map`/`Data.Set`

[Herbert Valerio Riedel]

On 2016-03-08 at 09:58:00 +0100, Henning Thielemann wrote:
>> On 2016-03-08 at 01:26:12 +0100, Dan Burton wrote:
>>> I would prefer that the Ord constraint be retained in the type signature,
>>> even if not used in the implementation.
>>
>> Just for the record: You'll have to actively suppress the resulting
>> warning if the Ord dictionary is not used by the implementation, as
>> -Wredundant-constraints is part of -Wall starting with GHC 8.0
>
> It seems to have changed:
>    https://ghc.haskell.org/trac/ghc/ticket/10635#comment:7

Indeed, see also

  https://ghc.haskell.org/ticket/11370#comment:32

which was the result of a lengthy debate...

Sadly, aspects in the warning design-space such as how to
classify/default warnings in combination with the 3-rls-policy tend to
drain the living will out of its participants (paraphrasing Simon
Marlow)...

> But I had those cases in mind when I asked for removing
> -Wredundant-constraints from -Wall.