Created
July 21, 2014 14:22
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List traversal with hask
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| listTraversal :: (Strong p, Monoidal (p [a])) => p a b -> p [a] [b] | |
| listTraversal p = dimap f g $ _2 $ ap2 (nil, cons) | |
| where | |
| f as = (as, as) | |
| g ([], (bs, _)) = bs | |
| g (_ , (_, bs)) = bs | |
| nil = return [] | |
| cons = return (:) `ap` lmap Prelude.head p `ap` lmap Prelude.tail (listTraversal p) |
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