Merge pull request #639 from nicluo/master

Support --version, -V in CLI

main/Main.hs

@@ -28,6 +28,7 @@ import           System.Posix.Signals
 import qualified Data.Map as Map
 import qualified Data.Text.Encoding as E
 import           Data.List (break, last)
+import           Data.Version (showVersion)
 
 -- IHaskell imports.
 import           IHaskell.Convert (convert)
@@ -46,6 +47,9 @@ import           IHaskell.IPython.Types
 import qualified IHaskell.IPython.Message.UUID as UUID
 import qualified IHaskell.IPython.Stdin as Stdin
 
+-- Cabal imports.
+import           Paths_ihaskell(version)
+
 -- GHC API imports.
 import           GHC hiding (extensions, language)
 
@@ -69,7 +73,7 @@ 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 +86,14 @@ 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 (showVersion version)
+  Nothing ->
+    putStrLn helpStr
+
 showingHelp :: IHaskellMode -> [Argument] -> IO () -> IO ()
 showingHelp mode flags act =
   case find (== Help) flags of
@@ -240,9 +252,9 @@ replyTo _ KernelInfoRequest{} replyHeader state =
     (state, KernelInfoReply
               { header = replyHeader
               , protocolVersion = "5.0"
-              , banner = "IHaskell " ++ VERSION_ipython_kernel ++ " GHC " ++ VERSION_ghc
+              , banner = "IHaskell " ++ (showVersion version) ++ " GHC " ++ VERSION_ghc
               , implementation = "IHaskell"
-              , implementationVersion = VERSION_ipython_kernel
+              , implementationVersion = showVersion version
               , languageInfo = LanguageInfo
                 { languageName = "haskell"
                 , languageVersion = VERSION_ghc

src/IHaskell/Flags.hs

@@ -32,6 +32,7 @@ data Argument = ConfFile String     -- ^ A file with commands to load at startup
               | GhcLibDir String    -- ^ Where to find the GHC libraries.
               | KernelDebug         -- ^ Spew debugging output from the kernel.
               | Help                -- ^ Display help text.
+              | Version             -- ^ Display version text.
               | ConvertFrom String
               | ConvertTo String
               | ConvertFromFormat NotebookFormat
@@ -57,7 +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)
@@ -70,9 +71,7 @@ parseFlags flags =
   in case modeIndex of
     Nothing ->
       -- Treat no mode as 'console'.
-      if "--help" `elem` flags
-        then Left $ showText (Wrap 100) $ helpText [] HelpFormatAll ihaskellArgs
-        else process ihaskellArgs flags
+      process ihaskellArgs flags
     Just 0 -> process ihaskellArgs flags
 
     Just idx ->
@@ -177,10 +176,12 @@ lhsStyleTex = LhsStyle "" "" "\\begin{code}" "\\end{code}" "\\begin{verbatim}" "
 
 ihaskellArgs :: Mode Args
 ihaskellArgs =
-  let descr = "Haskell for Interactive Computing."
+  let noMode = mode "IHaskell" defaultReport descr noArgs [helpFlag, versionFlag]
+      defaultReport = Args (ShowDefault helpStr) []
+      descr = "Haskell for Interactive Computing."
+      helpFlag = flagHelpSimple (add Help)
+      versionFlag = flagVersion (add Version)
       helpStr = showText (Wrap 100) $ helpText [] HelpFormatAll ihaskellArgs
-      onlyHelp = [flagHelpSimple (add Help)]
-      noMode = mode "IHaskell" (Args (ShowHelp helpStr) []) descr noArgs onlyHelp
   in noMode { modeGroupModes = toGroup allModes }
   where
     add flag (Args mode flags) = Args mode $ flag : flags