45 lines
1.4 KiB
Haskell
45 lines
1.4 KiB
Haskell
{- misc utility functions
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-
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- Copyright 2010-2011 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Utility.Misc where
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import System.IO
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import Control.Monad
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import GHC.IO.Encoding
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{- Sets a Handle to use the filesystem encoding. This causes data
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- written or read from it to be encoded/decoded the same
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- as ghc 7.4 does to filenames et. This special encoding
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- allows "arbitrary undecodable bytes to be round-tripped through it". -}
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fileEncoding :: Handle -> IO ()
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fileEncoding h = hSetEncoding h =<< getFileSystemEncoding
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{- A version of hgetContents that is not lazy. Ensures file is
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- all read before it gets closed. -}
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hGetContentsStrict :: Handle -> IO String
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hGetContentsStrict = hGetContents >=> \s -> length s `seq` return s
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{- A version of readFile that is not lazy. -}
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readFileStrict :: FilePath -> IO String
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readFileStrict = readFile >=> \s -> length s `seq` return s
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{- Like break, but the character matching the condition is not included
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- in the second result list.
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-
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- separate (== ':') "foo:bar" = ("foo", "bar")
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- separate (== ':') "foobar" = ("foobar", "")
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-}
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separate :: (a -> Bool) -> [a] -> ([a], [a])
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separate c l = unbreak $ break c l
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where
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unbreak r@(a, b)
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| null b = r
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| otherwise = (a, tail b)
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{- Breaks out the first line. -}
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firstLine :: String-> String
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firstLine = takeWhile (/= '\n')
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