ghc-mod-5.4.0.0: Happy Haskell Programming

Safe HaskellNone
LanguageHaskell2010

Language.Haskell.GhcMod.Utils

Synopsis

Documentation

dropWhileEnd :: (a -> Bool) -> [a] -> [a] Source

whenM :: Monad m => m Bool -> m () -> m () Source

ghcModExecutable :: IO FilePath Source

Returns the path to the currently running ghc-mod executable. With ghc<7.6 this is a guess but >=7.6 uses getExecutablePath.

withMappedFile :: (IOish m, GmState m, GmEnv m) => forall a. FilePath -> (FilePath -> m a) -> m a Source

makeAbsolute' :: FilePath -> IO FilePath Source

Make a path absolute by prepending the current directory (if it isn't already absolute) and applying normalise to the result.

If the path is already absolute, the operation never fails. Otherwise, the operation may fail with the same exceptions as getCurrentDirectory.

readProcess

Arguments

:: FilePath

Filename of the executable (see RawCommand for details)

-> [String]

any arguments

-> String

standard input

-> IO String

stdout

readProcess forks an external process, reads its standard output strictly, blocking until the process terminates, and returns the output string. The external process inherits the standard error.

If an asynchronous exception is thrown to the thread executing readProcess, the forked process will be terminated and readProcess will wait (block) until the process has been terminated.

Output is returned strictly, so this is not suitable for interactive applications.

This function throws an IOError if the process ExitCode is anything other than ExitSuccess. If instead you want to get the ExitCode then use readProcessWithExitCode.

Users of this function should compile with -threaded if they want other Haskell threads to keep running while waiting on the result of readProcess.

 > readProcess "date" [] []
 "Thu Feb  7 10:03:39 PST 2008\n"

The arguments are:

  • The command to run, which must be in the $PATH, or an absolute or relative path
  • A list of separate command line arguments to the program
  • A string to pass on standard input to the forked process.