cb81698b7e
This way, we can declare DynEncoding an instance of Show darcs-hash:20070827020833-a4fee-a84635bf911573022b780c17b2085ff814302b3e
30 lines
914 B
Haskell
30 lines
914 B
Haskell
-- | 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 informations.
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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.ByteString.Base (c2w)
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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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data ASCII = ASCII deriving Show
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charToASCII :: Char -> Word8
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charToASCII ch = if ch < '\128'
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then c2w 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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