17 lines
503 B
Haskell
17 lines
503 B
Haskell
module Data.ByteString.Char8.Util (
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previous
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, subBS
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) where
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import Data.ByteString.Char8 (ByteString)
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import qualified Data.ByteString.Char8 as BS (drop, index, take)
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import Prelude hiding (length)
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previous :: Char -> Int -> ByteString -> Int
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previous char position byteString
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| BS.index byteString position == char = position
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| otherwise = previous char (position - 1) byteString
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subBS :: Int -> Int -> ByteString -> ByteString
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subBS offset length = BS.take length . BS.drop offset
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