33 lines
593 B
Plaintext
33 lines
593 B
Plaintext
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data List a = { Nil, Cons a (List a) }
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defn map f l = {
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case l of {
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Nil -> { Nil }
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Cons x xs -> { Cons (f x) (map f xs) }
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}
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}
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defn foldl f b l = {
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case l of {
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Nil -> { b }
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Cons x xs -> { foldl f (f b x) xs }
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}
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}
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defn foldr f b l = {
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case l of {
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Nil -> { b }
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Cons x xs -> { f x (foldr f b xs) }
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}
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}
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defn list = { Cons 1 (Cons 2 (Cons 3 (Cons 4 Nil))) }
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defn add x y = { x + y }
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defn sum l = { foldr add 0 l }
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defn skipAdd x y = { y + 1 }
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defn length l = { foldr skipAdd 0 l }
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defn main = { sum list + length list }
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