Make kernelName configurable

This does not change the display name, so it doesn't seem that useful on
its own.

main/Main.hs

@@ -101,6 +101,8 @@ parseKernelArgs = foldl' addFlag defaultKernelSpecOptions
       kernelSpecOpts { kernelSpecUseStack = True }
     addFlag kernelSpecOpts (KernelspecEnvFile fp) =
       kernelSpecOpts { kernelSpecEnvFile = Just fp }
+    addFlag kernelSpecOpts (KernelName name) =
+      kernelSpecOpts { kernelName = name }
     addFlag _kernelSpecOpts flag = error $ "Unknown flag" ++ show flag
 
 -- | Run the IHaskell language kernel.

src/IHaskell/Flags.hs

@@ -40,6 +40,7 @@ data Argument = ConfFile String     -- ^ A file with commands to load at startup
               | KernelspecInstallPrefix String
               | KernelspecUseStack
               | KernelspecEnvFile FilePath
+              | KernelName String
   deriving (Eq, Show)
 
 data LhsStyle string =
@@ -133,6 +134,10 @@ kernelEnvFileFlag =
     "<file>"
     "Load environment from this file when kernel is installed"
 
+kernelNameFlag :: Flag Args
+kernelNameFlag = flagReq ["kernel-name"] (store KernelName) "<name>"
+  "Specify a name for the install kernel (default: haskell)"
+
 confFlag :: Flag Args
 confFlag = flagReq ["conf", "c"] (store ConfFile) "<rc.hs>"
              "File with commands to execute at start; replaces ~/.ihaskell/rc.hs."
@@ -153,7 +158,7 @@ store constructor str (Args md prev) = Right $ Args md $ constructor str : prev
 installKernelSpec :: Mode Args
 installKernelSpec =
   mode "install" (Args InstallKernelSpec []) "Install the Jupyter kernelspec." noArgs
-    [ghcLibFlag, ghcRTSFlag, kernelDebugFlag, confFlag, installPrefixFlag, helpFlag, kernelStackFlag, kernelEnvFileFlag]
+    [ghcLibFlag, ghcRTSFlag, kernelDebugFlag, confFlag, installPrefixFlag, helpFlag, kernelStackFlag, kernelEnvFileFlag, kernelNameFlag]
 
 kernel :: Mode Args
 kernel = mode "kernel" (Args (Kernel Nothing) []) "Invoke the IHaskell kernel." kernelArg

src/IHaskell/IPython.hs

@@ -8,7 +8,6 @@ module IHaskell.IPython (
     getIHaskellDir,
     getSandboxPackageConf,
     subHome,
-    kernelName,
     KernelSpecOptions(..),
     defaultKernelSpecOptions,
     installLabextension,
@@ -45,6 +44,7 @@ data KernelSpecOptions =
          , kernelSpecInstallPrefix :: Maybe String
          , kernelSpecUseStack :: Bool              -- ^ Whether to use @stack@ environments.
          , kernelSpecEnvFile :: Maybe FilePath
+         , kernelName :: String                    -- ^ The Jupyter kernel name.
          }
 
 defaultKernelSpecOptions :: KernelSpecOptions
@@ -58,12 +58,9 @@ defaultKernelSpecOptions = KernelSpecOptions
   , kernelSpecInstallPrefix = Nothing
   , kernelSpecUseStack = False
   , kernelSpecEnvFile = Nothing
+  , kernelName = "haskell"
   }
 
--- | The IPython kernel name.
-kernelName :: String
-kernelName = "haskell"
-
 ipythonCommand :: SH.Sh SH.FilePath
 ipythonCommand = do
   jupyterMay <- SH.which "jupyter"
@@ -148,14 +145,14 @@ installKernelspec repl opts = void $ do
 
   let kernelSpec = KernelSpec
         { kernelDisplayName = "Haskell"
-        , kernelLanguage = kernelName
+        , kernelLanguage = kernelName opts
         , kernelCommand = [ihaskellPath, "kernel", "{connection_file}"] ++ kernelFlags
         }
 
   -- Create a temporary directory. Use this temporary directory to make a kernelspec directory; then,
   -- shell out to IPython to install this kernelspec directory.
   SH.withTmpDir $ \tmp -> do
-    let kernelDir = tmp SH.</> kernelName
+    let kernelDir = tmp SH.</> kernelName opts
     let filename = kernelDir SH.</> ("kernel.json" :: SH.FilePath)
 
     SH.mkdir_p kernelDir
@@ -163,7 +160,7 @@ installKernelspec repl opts = void $ do
     let files = ["kernel.js", "logo-64x64.svg"]
     forM_ files $ \file -> do
       src <- liftIO $ Paths.getDataFileName $ "html/" ++ file
-      SH.cp (SH.fromText $ T.pack src) (tmp SH.</> kernelName SH.</> file)
+      SH.cp (SH.fromText $ T.pack src) (tmp SH.</> kernelName opts SH.</> file)
 
     ipython <- locateIPython