60 lines
1.9 KiB
Haskell
60 lines
1.9 KiB
Haskell
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module Encoding.LetterToNumber
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( encltn
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, decltn
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) where
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import Data.Char (ord, chr, isAscii, isAlpha, isSpace, isDigit, toUpper, isLatin1)
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import Data.List (intercalate)
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import Data.ByteString (ByteString)
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import qualified Data.ByteString.Char8 as BC
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charToNumber :: Char -> ByteString
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charToNumber c
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| isAlpha c = BC.pack $ show $ ord (toUpper c) - ord 'A' + 1
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| isSpace c = BC.pack "0"
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| otherwise = BC.singleton c
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-- | isAlpha c = show $ ord (toUpper c) - ord 'A' + 1
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-- | isSpace c = "0"
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-- -- | isLatin1 c = [c]
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-- | otherwise = [c]
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numberToChar :: String -> Char
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numberToChar s
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| s == "0" = ' '
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| all isDigit s = chr $ read s + ord 'A' -1
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| otherwise = head s
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-- | otherwise = chr $ read s + ord 'A' - 1
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encltn :: ByteString -> ByteString
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encltn input = go (BC.unpack input) []
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where
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go :: String -> [ByteString] -> ByteString
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go [] acc = BC.intercalate (BC.pack "-") (reverse acc)
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go (x:xs) acc
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-- | not (isAscii x) = go xs (BC.singleton x : acc)
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| not (isAscii x) = error "Non-ASCII character detected"
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| otherwise = go xs (charToNumber x : acc)
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-- encltn input = BC.intercalate (BC.pack "-") $ map charToNumber' $ BC.unpack input
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-- where
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-- charToNumber' c
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-- | not (isAscii c)= BC.singleton c
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-- | otherwise = charToNumber c
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decltn :: ByteString -> ByteString
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decltn input = BC.pack $ concatMap (processSegment . BC.unpack) $ BC.split '-' input
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where
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processSegment :: String -> String
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processSegment s
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| all isDigit s = [numberToChar s]
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| otherwise = s
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-- decltn input = BC.pack $ go $ BC.split '-' input
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-- where
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-- go :: [ByteString] -> String
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-- go [] = []
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-- go (x:xs) =
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-- let str = BC.unpack x
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-- in numberToChar str ++ go xs
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-- in case all isDigit str of
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-- True -> numberToChar str : go xs
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-- False -> str ++ go xs
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