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gallais/Unfold.hs

Created February 22, 2015 00:26
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Unfold of a Fix
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Unfold.hs
module Unfold where
newtype Fix f = InFix { outFix :: f (Fix f) }
unfoldFix :: Functor f => (s -> f s) -> s -> Fix f
unfoldFix node = go
where go = InFix . fmap go . node
data ListF a r = LNil | LCons a r
data TreeF a r = TNil | TLeaf a | TBranch r r
type List a = Fix (ListF a)
type Tree a = Fix (TreeF a)
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