proposal #3335: make some Applicative functions into methods,
and split off Data.Functor
lemming at henning-thielemann.de
Fri Jul 3 19:08:41 EDT 2009
Ross Paterson schrieb:
> On Tue, Jun 30, 2009 at 01:37:05PM +0200, Henning Thielemann wrote:
>> This sounds like a rather ad-hoc extension of the already complicated
>> hierarchy of those category classes. Are there particular examples where
>> the specialisation is needed and where it cannot be done by optimizer
> Here's one for (<$). In Data.Sequence, I could define
> x <$ s = replicate (size s) x
> (using Louis Wasserman's replicate), which would take O(log n) time and
> space, a big improvement over the O(n) version using const and fmap.
Would it be reasonable to let the optimizer replace (x <$ s) by
(replicate (size s) x) via RULES?
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