Add basic tooltip functionality and implement object_info_request and object_info_reply messages.

IPython has a tooltip feature which shows an info box under the cursor containing info about the current object. I have ported this to IHaskell. Basically, tooltip.js sends an object_info_request message to the kernel and the kernel responds with type information about the closest object.

IHaskell/Config.hs

 {-# LANGUAGE QuasiQuotes #-}
 -- | Description : IPython configuration files are compiled-into IHaskell
-module IHaskell.Config (ipython, notebook, console, qtconsole, customjs) where
+module IHaskell.Config (ipython, notebook, console, qtconsole, customjs, tooltipjs) where
 
 import Data.String.Here
 import ClassyPrelude
@@ -19,3 +19,6 @@ qtconsole = [template|config/ipython_qtconsole_config.py|]
 
 customjs :: String
 customjs = [template|config/custom.js|]
+
+tooltipjs :: String
+tooltipjs = [template|deps/tooltip.js|]

IHaskell/IPython.hs

@@ -97,6 +97,12 @@ writeConfigFilesTo profileDir ihaskellPath = do
     -- The custom directory many not exist, in which case we'll create it.
     mkdir_p (conf "static/custom/")
     writeFile (conf "static/custom/custom.js")      Config.customjs
+
+    -- The notebook/js directory many not exist, in which case we'll create it.
+    mkdir_p (conf "static/notebook/")
+    mkdir_p (conf "static/notebook/js")
+    writeFile (conf "static/notebook/js/tooltip.js") Config.tooltipjs
+
   where
     conf filename = fromText $ profileDir ++ filename
 

IHaskell/Message/Parser.hs

@@ -75,7 +75,7 @@ parser :: MessageType            -- ^ The message type being parsed.
 parser KernelInfoRequestMessage  = kernelInfoRequestParser
 parser ExecuteRequestMessage     = executeRequestParser
 parser CompleteRequestMessage    = completeRequestParser
-parser ObjectInfoRequestMessage    = objectInfoRequestParser
+parser ObjectInfoRequestMessage  = objectInfoRequestParser
 parser other = error $ "Unknown message type " ++ show other
 
 -- | Parse a kernel info request.

IHaskell/Types.hs

@@ -130,6 +130,8 @@ instance FromJSON MessageType where
     "pyin"                -> return InputMessage
     "complete_request"    -> return CompleteRequestMessage
     "complete_reply"      -> return CompleteReplyMessage
+    "object_info_request" -> return ObjectInfoRequestMessage
+    "object_info_reply"   -> return ObjectInfoReplyMessage
     _                     -> fail ("Unknown message type: " ++ show s)
   parseJSON _ = fail "Must be a string."
 
@@ -269,4 +271,5 @@ replyType :: MessageType -> MessageType
 replyType KernelInfoRequestMessage = KernelInfoReplyMessage
 replyType ExecuteRequestMessage = ExecuteReplyMessage
 replyType CompleteRequestMessage = CompleteReplyMessage
+replyType ObjectInfoRequestMessage = ObjectInfoReplyMessage
 replyType messageType = error $ "No reply for message type " ++ show messageType

Main.hs

@@ -167,6 +167,8 @@ replyTo _ creq@CompleteRequest{} replyHeader state = trace (show creq) $ do
     cr <- makeCompletions replyHeader creq
     return (state,  cr)
 
+-- | Reply to the object_info_request message. Given an object name, return
+-- | the associated type calculated by GHC.
 replyTo _ ObjectInfoRequest{objectName=oname} replyHeader state = do
          dflags <- getSessionDynFlags
          maybeDocs  <- flip gcatch (\(e::SomeException) -> return Nothing) $ do