32 lines
988 B
Haskell
32 lines
988 B
Haskell
{-# LANGUAGE DeriveDataTypeable #-}
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-- | ASCII (American Standard Code for Information Interchange) is the
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-- \"normal\" computer encoding using the byte values 0-127 to represent
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-- characters. Refer to <http://en.wikipedia.org/wiki/ASCII> for
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-- more information.
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module Data.Encoding.ASCII
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(ASCII(..)) where
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import Control.Exception (throwDyn)
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import Data.ByteString (pack)
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import qualified Data.ByteString.Lazy as Lazy (pack)
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import Data.ByteString.Char8 (unpack)
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import Data.Char (ord)
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import qualified Data.ByteString.Lazy as Lazy
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import Data.Encoding.Base
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import Data.Word
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import Data.Typeable
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data ASCII = ASCII deriving (Show,Eq,Typeable)
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charToASCII :: Char -> Word8
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charToASCII ch = if ch < '\128'
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then fromIntegral $ ord ch
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else throwDyn (HasNoRepresentation ch)
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instance Encoding ASCII where
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encode _ str = pack (map charToASCII str)
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encodeLazy _ str = Lazy.pack (map charToASCII str)
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encodable _ ch = ch < '\128'
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decode _ = unpack
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decodable _ = const True
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