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https://github.com/idris-lang/Idris2.git
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22 lines
509 B
Idris
22 lines
509 B
Idris
%default partial
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data Vect : Nat -> Type -> Type where
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Nil : Vect Z a
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(::) : a -> Vect k a -> Vect (S k) a
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append : Vect n a -> Vect m a -> Vect (n + m) a
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append [] ys = ys
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-- append (x :: xs) ys = x :: append xs ys
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data Fin : Nat -> Type where
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FZ : Fin (S k)
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FS : Fin k -> Fin (S k)
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lookup : Fin n -> Vect n a -> a
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lookup FZ (x :: xs) = x
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lookup (FS k) (x :: xs) = lookup k xs
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zip : Vect n a -> Vect n b -> Vect n (a, b)
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zip [] [] = []
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zip (x :: xs) (y :: ys) = (x, y) :: zip xs ys
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