Merge pull request #94.

Options/Applicative/Extra.hs

@@ -10,6 +10,7 @@ module Options.Applicative.Extra (
   customExecParser,
   customExecParserMaybe,
   execParserPure,
+  handleParseResult,
   ParserFailure(..),
   ParserResult(..),
   ParserPrefs(..),
@@ -57,18 +58,21 @@ execParser = customExecParser (prefs idm)
 
 -- | Run a program description with custom preferences.
 customExecParser :: ParserPrefs -> ParserInfo a -> IO a
-customExecParser pprefs pinfo = do
-  args <- getArgs
-  case execParserPure pprefs pinfo args of
-    Success a -> return a
-    Failure failure -> do
+customExecParser pprefs pinfo
+  = execParserPure pprefs pinfo <$> getArgs
+  >>= handleParseResult
+
+-- | Handle `ParserResult`.
+handleParseResult :: ParserResult a -> IO a
+handleParseResult (Success a) = return a
+handleParseResult (Failure failure) = do
       progn <- getProgName
       let (msg, exit) = execFailure failure progn
       case exit of
         ExitSuccess -> putStrLn msg
         _           -> hPutStrLn stderr msg
       exitWith exit
-    CompletionInvoked compl -> do
+handleParseResult (CompletionInvoked compl) = do
       progn <- getProgName
       msg <- execCompletion compl progn
       putStr msg

optparse-applicative.cabal

@@ -1,5 +1,5 @@
 name:                optparse-applicative
-version:             0.9.0
+version:             0.9.1
 synopsis:            Utilities and combinators for parsing command line options
 description:
     Here is a simple example of an applicative option parser: