My concern here isn't efficiency. Data.Sequence.toList should just be a
reexport of Foldable.toList monomorphized to Seq. I just want a consistent
API with other modules in containers.
I do see that Map.toList /= Foldable.toList. But Set.toList ==
Foldable.toList, and it's not obvious to me why Set should have toList and
not Seq.
On Sat, Mar 7, 2026, 3:37 PM Dan Dart <haskellcafe(a)dandart.co.uk> wrote:
> Well, it's got a Foldable instance already, which gives you a toList for
> anything Foldable, is it going to get any more efficient than this one?
> That's one of the few reasons to add extra functions already covered by
> type class instances, no?
>
> Cheers
>
> On Sat, 7 Mar 2026, 23:20 , <brandonchinn178(a)gmail.com> wrote:
>
>> An issue was opened on containers back in 2020 to add a monomorphic
>> Data.Sequence.toList function:
>> https://github.com/haskell/containers/issues/744. It was suggested to
>> ask via the libraries list, and the previous reporter preferred to close
>> the issue instead of continuing the process. I'm opening it back up:
>> https://github.com/haskell/containers/issues/1184. Same motivation as
>> the original issue; specifically, I always workaround this with
>>
>> import Data.Foldable qualified as Seq (toList)
>> import Data.Sequence (Seq)
>> import Data.Sequence qualified as Seq
>>
>> It's odd that Data.Sequence doesn't provide toList when Map and Set do.
>> Are there any objections to this?
>>
>> Best,
>> Brandon Chinn
>> _______________________________________________
>> Libraries mailing list -- libraries(a)haskell.org
>> To unsubscribe send an email to libraries-leave(a)haskell.org
>>
>
An issue was opened on containers back in 2020 to add a monomorphic Data.Sequence.toList function: https://github.com/haskell/containers/issues/744. It was suggested to ask via the libraries list, and the previous reporter preferred to close the issue instead of continuing the process. I'm opening it back up: https://github.com/haskell/containers/issues/1184. Same motivation as the original issue; specifically, I always workaround this with
import Data.Foldable qualified as Seq (toList)
import Data.Sequence (Seq)
import Data.Sequence qualified as Seq
It's odd that Data.Sequence doesn't provide toList when Map and Set do. Are there any objections to this?
Best,
Brandon Chinn
