[Haskell-cafe] The difficulty of designing a sequence class

[Brian Hulley]

David Menendez wrote:
> ajb at spamcop.net writes:
>> I didn't get around to fixing Sequence because there wasn't a need
>> for it yet, but yes, it should be done.
>
> That's a tough call to make. Changing the kind of Sequence to * from *
> -> * means losing the Functor, Monad, and MonadPlus superclasses and
> all the various maps and zips.

But there's no option if you want to be able to support non-polymorphic 
sequences like Data.ByteString etc. I think the Functor class is just 
fundamentally too limited - it assumes the whole world is polymorphic and it 
isn't.

Also, MPTC's mean we would gain Monoid.

Regards, Brian.

-- 
Logic empowers us and Love gives us purpose.
Yet still phantoms restless for eras long past,
congealed in the present in unthought forms,
strive mightily unseen to destroy us.

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