23 lines
467 B
Haskell
23 lines
467 B
Haskell
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module Encoding.Rotate
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( rotate ) where
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import Data.Maybe (fromMaybe)
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upperCase = ['A' .. 'Z']
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lowerCase = ['a' .. 'z']
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-- rotate :: Int * -> String
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rotate :: Int -> String -> String
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rotate n s = map (rotchar n) s
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where
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rotchar n c =
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case (lookup c $ transp n lowerCase) of
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Just x -> x
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Nothing -> fromMaybe c (lookup c $ transp n upperCase)
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transp :: Int -> [Char] -> [(Char, Char)]
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transp n x = zip x ((drop n x) ++ (take n x))
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