Create showDefault to show version when flagged

main/Main.hs

@@ -69,7 +69,7 @@ main = do
     Right args        -> ihaskell args
 
 ihaskell :: Args -> IO ()
-ihaskell (Args (ShowHelp help) _) = putStrLn help
+ihaskell (Args (ShowDefault helpStr) args) = showDefault helpStr args
 ihaskell (Args ConvertLhs args) = showingHelp ConvertLhs args $ convert args
 ihaskell (Args InstallKernelSpec args) = showingHelp InstallKernelSpec args $ do
   let kernelSpecOpts = parseKernelArgs args
@@ -82,6 +82,14 @@ ihaskell a@(Args (Kernel Nothing) _) = do
   hPutStrLn stderr "This may be a bug!"
   hPrint stderr a
 
+showDefault :: String -> [Argument] -> IO ()
+showDefault helpStr flags =
+  case find (== Version) flags of
+  Just _ ->
+    putStrLn VERSION_ipython_kernel
+  Nothing ->
+    putStrLn helpStr
+
 showingHelp :: IHaskellMode -> [Argument] -> IO () -> IO ()
 showingHelp mode flags act =
   case find (== Help) flags of

src/IHaskell/Flags.hs

-{-# LANGUAGE CPP, NoImplicitPrelude, DeriveFunctor #-}
+{-# LANGUAGE NoImplicitPrelude, DeriveFunctor #-}
 
 module IHaskell.Flags (
     IHaskellMode(..),
@@ -58,7 +58,7 @@ data NotebookFormat = LhsMarkdown
   deriving (Eq, Show)
 
 -- Which mode IHaskell is being invoked in.
-data IHaskellMode = ShowHelp String
+data IHaskellMode = ShowDefault String
                   | InstallKernelSpec
                   | ConvertLhs
                   | Kernel (Maybe String)
@@ -71,9 +71,7 @@ parseFlags flags =
   in case modeIndex of
     Nothing ->
       -- Treat no mode as 'console'.
-      if "--version" `elem` flags || "-V" `elem` flags
-        then Left VERSION_ipython_kernel
-        else process ihaskellArgs flags
+      process ihaskellArgs flags
     Just 0 -> process ihaskellArgs flags
 
     Just idx ->
@@ -179,7 +177,7 @@ lhsStyleTex = LhsStyle "" "" "\\begin{code}" "\\end{code}" "\\begin{verbatim}" "
 ihaskellArgs :: Mode Args
 ihaskellArgs =
   let noMode = mode "IHaskell" defaultReport descr noArgs [helpFlag, versionFlag]
-      defaultReport = Args (ShowHelp helpStr) []
+      defaultReport = Args (ShowDefault helpStr) []
       descr = "Haskell for Interactive Computing."
       helpFlag = flagHelpSimple (add Help)
       versionFlag = flagVersion (add Version)