27 lines
472 B
Idris
27 lines
472 B
Idris
module Data.Permutation
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import Data.Vect
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%default total
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public export
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Permutation : Nat -> Type
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Permutation n = Vect n (Fin n)
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public export
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identity : {n : _} -> Permutation n
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identity {n=Z} = []
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identity {n=S n} = FZ :: map FS identity
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public export
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reversed : {n : _} -> Permutation n
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reversed {n=Z} = []
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reversed {n=S n} = last :: map weaken reversed
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public export
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permuteVect : Permutation n -> Vect n a -> Vect n a
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permuteVect p v = map (\i => index i v) p
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