Proposal for deepseq: Data.Sequence.Seq instance for NFData

[Alexey Karakulov]

Oops.. Probably I get why toList is preferred method for making instances :)
My rnfFoldable does not work.
But this version must be correct:

> rnfFoldable :: (NFData a, Foldable f) => f a -> ()
> rnfFoldable = Foldable.foldl (\z x -> rnf x `seq` z) ()


On Tue, Jul 12, 2011 at 6:21 PM, Alexey Karakulov <ankarakulov at gmail.com>wrote:

> My proposal is qiute straightforward. The patch is attached and it's
> essence is in these lines:
>
> > instance NFData a => NFData (Data.Sequence.Seq a) where
> >    rnf = rnf . Foldable.toList
>
> [Discussion part]
>
> I choosed toList method to keep the code style, but I'm not sure it's
> efficient to create cons'es when we could just fold:
>
> > rnfFoldable :: (NFData a, Foldable f) => f a -> ()
> > rnfFoldable = Foldable.foldMap rnf
>
> Or it's better to do this with foldl (while not so nice at is was with
> using () as monoid):
>
> > rnfFoldable = Foldable.foldl (const rnf) ()
>
> There was a proposal to add strict folds to Foldable type class, so we can
> use foldl' there.
>
> My proposal is to add the instance in either way.
>
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