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Created August 7, 2018 14:56
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from wikipedia Catamorphism
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Catamorphism.hs
type StepAlgebra b = (b, b->b) -- the algebras, which we encode as pairs (nil, next)
data Nat = Zero | Succ Nat -- which is the initial algebra for the functor described above
foldSteps :: StepAlgebra b -> (Nat -> b) -- the catamorphisms map from Nat to b
foldSteps (nil, next) Zero = nil
foldSteps (nil, next) (Succ nat) = next $ foldSteps (nil, next) nat
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