42 lines
938 B
Text
42 lines
938 B
Text
data List (a) where {
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Nil : List (a)
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Cons : a -> List (a) -> List (a)
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};
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data Bool () where {
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True : Bool ()
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False : Bool ()
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};
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-- hello_world = Cons 'h' (Cons 'e' (Cons 'l' (Cons 'l' (Cons 'o' (Cons ' ' (Cons 'w' (Cons 'o' (Cons 'r' (Cons 'l' (Cons 'd' Nil)))))))))) ;
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-- length : List (a) -> Int ;
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-- length xs = case xs of {
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-- Nil => 0 ;
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-- Cons x xs => length xs
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-- };
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-- head : List (a) -> a ;
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-- head xs = case xs of {
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-- Cons x xs => x
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-- };
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firstIsOne : List (Int) -> Bool () ;
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firstIsOne : List (Int) -> Bool () ;
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firstIsOne xs = case xs of {
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Cons x xs => case x of {
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1 => True ;
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_ => case xs of {
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Cons x xs => False ;
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_ => False
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}
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};
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_ => False
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};
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-- firstIsOne :: [Int] -> Bool
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-- firstIsOne xs = case xs of
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-- (1 : xs) -> True
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-- _ -> False
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main = firstIsOne (Cons 'a' Nil)
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