[Haskell-cafe] Re: excercise - a completely lazy sorting algorithm

Raynor Vliegendhart shinnonoir at gmail.com
Sun Jul 12 05:03:35 EDT 2009


On 7/9/09, Heinrich Apfelmus <apfelmus at quantentunnel.de> wrote:
>
> Of course, some part of algorithm has to be recursive, but this can be
> outsourced to a general recursion scheme, like the hylomorphism
>
>    hylo :: Functor f => (a -> f a) -> (f b -> b) -> (a -> b)
>    hylo f g = g . fmap (hylo f g) . f
>

Is that definition of hylo actually usuable? A few on IRC tried to use
that definition for a few examples, but the examples failed to
terminate or blew up the stack.


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