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16 lines
459 B
Idris
16 lines
459 B
Idris
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init : a -> c -> List b -> List (a, b, c)
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init a c = map (uncurry (,)) . map (a,) . map (,c)
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unzip : List (a, b) -> (List a, List b)
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unzip [] = ([], [])
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unzip ((a, b) :: abs)
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= let (as, bs) = unzip abs in
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(a :: as, b :: bs)
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unzip4 : List (a, b, c, d) -> (List a, List b, List c, List d)
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unzip4 [] = ([], [], [], [])
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unzip4 (abcd :: abcds)
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= let (a, b, c, d) = abcd
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(as, bs, cs, ds) = unzip4 abcds
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in (a :: as, b :: bs, c :: cs, d :: ds)
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