Completing reformatting and adding it to test suite

.travis.yml

@@ -48,6 +48,7 @@ script:
  - travis_retry cabal configure --enable-tests
  - travis_retry cabal test --show-details=always
 
+ - ./verify_formatting.py
  - cabal sdist
 
 # The following scriptlet checks that the resulting source distribution can be built & installed

src/IHaskell/Convert.hs

@@ -2,7 +2,7 @@
 module IHaskell.Convert (convert) where
 
 import           Control.Monad.Identity (Identity(Identity), unless, when)
-import           IHaskell.Convert.Args (ConvertSpec(ConvertSpec, convertInput, convertLhsStyle, convertOutput, convertOverwriteFiles, convertToIpynb), fromJustConvertSpec, toConvertSpec)
+import           IHaskell.Convert.Args (ConvertSpec(..), fromJustConvertSpec, toConvertSpec)
 import           IHaskell.Convert.IpynbToLhs (ipynbToLhs)
 import           IHaskell.Convert.LhsToIpynb (lhsToIpynb)
 import           IHaskell.Flags (Argument)

src/IHaskell/Convert/Args.hs

@@ -50,7 +50,6 @@ isFormatSpec (ConvertToFormat _) = True
 isFormatSpec (ConvertFromFormat _) = True
 isFormatSpec _ = False
 
-
 toConvertSpec :: [Argument] -> ConvertSpec Maybe
 toConvertSpec args = mergeArgs otherArgs (mergeArgs formatSpecArgs initialConvertSpec)
   where

src/IHaskell/Convert/IpynbToLhs.hs

@@ -13,8 +13,7 @@ import qualified Data.Text.Lazy as T (concat, fromStrict, Text, unlines)
 import qualified Data.Text.Lazy.IO as T (writeFile)
 import           Data.Vector (Vector)
 import qualified Data.Vector as V (map, mapM, toList)
-import           IHaskell.Flags (LhsStyle(lhsBeginCode, lhsBeginOutput, lhsCodePrefix, lhsEndCode,
-          lhsEndOutput, lhsOutputPrefix))
+import           IHaskell.Flags (LhsStyle(..))
 
 ipynbToLhs :: LhsStyle T.Text
            -> FilePath -- ^ the filename of an ipython notebook

src/IHaskell/Convert/LhsToIpynb.hs

@@ -41,7 +41,6 @@ isEmptyMD :: (Eq a, Monoid a) => CellLine a -> Bool
 isEmptyMD (MarkdownLine a) = a == mempty
 isEmptyMD _ = False
 
-
 untag :: CellLine t -> t
 untag (CodeLine a) = a
 untag (OutputLine a) = a

src/IHaskell/Display.hs

@@ -86,8 +86,6 @@ instance IHaskellDisplay a => IHaskellDisplay [a] where
     displays <- mapM display disps
     return $ ManyDisplay displays
 
-
-
 -- | Encode many displays into a single one. All will be output.
 many :: [Display] -> Display
 many = ManyDisplay

src/IHaskell/Eval/Completion.hs

@@ -60,6 +60,7 @@ data CompletionType = Empty
 extName (FlagSpec { flagSpecName = name }) = name
 #else
 extName (name, _, _) = name
+
 exposedName = id
 #endif
 complete :: String -> Int -> Interpreter (String, [String])
@@ -250,13 +251,14 @@ completionTarget code cursor = expandCompletionPiece pieceToComplete
   where
     pieceToComplete = map fst <$> find (elem cursor . map snd) pieces
     pieces = splitAlongCursor $ split splitter $ zip code [1 ..]
-    splitter = defaultSplitter { 
-    -- Split using only the characters, which are the first elements of
-    -- the (char, index) tuple
-    delimiter = Delimiter [uncurry isDelim], 
-                                             -- Condense multiple delimiters into one and then drop
-                                             -- them.
-                                             condensePolicy = Condense, delimPolicy = Drop }
+    splitter = defaultSplitter
+      { 
+      -- Split using only the characters, which are the first elements of the (char, index) tuple
+      delimiter = Delimiter [uncurry isDelim]
+      -- Condense multiple delimiters into one and then drop them.
+      , condensePolicy = Condense
+      , delimPolicy = Drop
+      }
 
     isDelim :: Char -> Int -> Bool
     isDelim char idx = char `elem` neverIdent || isSymbol char

src/IHaskell/Eval/Evaluate.hs

@@ -6,7 +6,12 @@
 This module exports all functions used for evaluation of IHaskell input.
 -}
 module IHaskell.Eval.Evaluate (
-  interpret, evaluate, Interpreter, liftIO, typeCleaner, globalImports
+    interpret,
+    evaluate,
+    Interpreter,
+    liftIO,
+    typeCleaner,
+    globalImports,
     ) where
 
 import           ClassyPrelude hiding (init, last, liftIO, head, hGetContents, tail, try)
@@ -77,16 +82,25 @@ import qualified  IHaskell.IPython.Message.UUID      as UUID
 import           Paths_ihaskell (version)
 import           Data.Version (versionBranch)
 
-data ErrorOccurred = Success | Failure deriving (Show, Eq)
+data ErrorOccurred = Success
+                   | Failure
+  deriving (Show, Eq)
 
 -- | Set GHC's verbosity for debugging
 ghcVerbosity :: Maybe Int
 ghcVerbosity = Nothing -- Just 5
 
 ignoreTypePrefixes :: [String]
-ignoreTypePrefixes = ["GHC.Types", "GHC.Base", "GHC.Show", "System.IO",
-                      "GHC.Float", ":Interactive", "GHC.Num", "GHC.IO",
-                      "GHC.Integer.Type"]
+ignoreTypePrefixes = [ "GHC.Types"
+                     , "GHC.Base"
+                     , "GHC.Show"
+                     , "System.IO"
+                     , "GHC.Float"
+                     , ":Interactive"
+                     , "GHC.Num"
+                     , "GHC.IO"
+                     , "GHC.Integer.Type"
+                     ]
 
 typeCleaner :: String -> String
 typeCleaner = useStringType . foldl' (.) id (map (`replace` "") fullPrefixes)
@@ -98,14 +112,12 @@ write :: GhcMonad m => KernelState -> String -> m ()
 write state x = when (kernelDebug state) $ liftIO $ hPutStrLn stderr $ "DEBUG: " ++ x
 
 type Interpreter = Ghc
-
 #if MIN_VERSION_ghc(7, 8, 0)
    -- GHC 7.8 exports a MonadIO instance for Ghc
 #else
 instance MonadIO.MonadIO Interpreter where
   liftIO = MonadUtils.liftIO
 #endif
-
 globalImports :: [String]
 globalImports =
   [ "import IHaskell.Display()"
@@ -118,23 +130,23 @@ globalImports =
   , "import qualified Language.Haskell.TH as IHaskellTH"
   ]
 
--- | Run an interpreting action. This is effectively runGhc with
--- initialization and importing. First argument indicates whether `stdin`
--- is handled specially, which cannot be done in a testing environment.
+-- | Run an interpreting action. This is effectively runGhc with initialization and importing. First
+-- argument indicates whether `stdin` is handled specially, which cannot be done in a testing
+-- environment.
 interpret :: String -> Bool -> Interpreter a -> IO a
 interpret libdir allowedStdin action = runGhc (Just libdir) $ do
   -- If we're in a sandbox, add the relevant package database
   sandboxPackages <- liftIO getSandboxPackageConf
   initGhci sandboxPackages
   case ghcVerbosity of
-    Just verb -> do dflags <- getSessionDynFlags
+    Just verb -> do
+      dflags <- getSessionDynFlags
       void $ setSessionDynFlags $ dflags { verbosity = verb }
     Nothing -> return ()
 
   initializeImports
 
-  -- Close stdin so it can't be used.
-  -- Otherwise it'll block the kernel forever.
+  -- Close stdin so it can't be used. Otherwise it'll block the kernel forever.
   dir <- liftIO getIHaskellDir
   let cmd = printf "IHaskell.IPython.Stdin.fixStdin \"%s\"" dir
   when allowedStdin $ void $
@@ -144,13 +156,11 @@ interpret libdir allowedStdin action = runGhc (Just libdir) $ do
 
   -- Run the rest of the interpreter
   action
-
 #if MIN_VERSION_ghc(7,10,0)
 packageIdString' dflags = packageKeyPackageIdString dflags
 #else
 packageIdString' dflags = packageIdString
 #endif
-
 -- | Initialize our GHC session with imports and a value for 'it'.
 initializeImports :: Interpreter ()
 initializeImports = do
@@ -219,8 +229,8 @@ initializeImports = do
 -- | Give a value for the `it` variable.
 initializeItVariable :: Interpreter ()
 initializeItVariable = do
-  -- This is required due to the way we handle `it` in the wrapper
-  -- statements - if it doesn't exist, the first statement will fail.
+  -- This is required due to the way we handle `it` in the wrapper statements - if it doesn't exist,
+  -- the first statement will fail.
   void $ runStmt "let it = ()" RunToCompletion
 
 -- | Publisher for IHaskell outputs. The first argument indicates whether this output is final
@@ -501,8 +511,7 @@ evalCommand output (Directive LoadModule mods) state = wrapExecution state $ do
           '-' -> (words remainder, True)
           _   -> (words stripped, False)
 
-  forM_ modules $ \modl ->
-    if removeModule
+  forM_ modules $ \modl -> if removeModule
                              then removeImport modl
                              else evalImport $ "import " ++ modl
 
@@ -512,25 +521,26 @@ evalCommand a (Directive SetOption opts) state = do
   write state $ "Option: " ++ opts
   let (existing, nonExisting) = partition optionExists $ words opts
   if not $ null nonExisting
-  then
-    let err = "No such options: " ++ intercalate ", " nonExisting in
-    return EvalOut {
-      evalStatus = Failure,
-      evalResult = displayError err,
-      evalState = state,
-      evalPager = "",
-      evalComms = []
+    then let err = "No such options: " ++ intercalate ", " nonExisting
+         in return
+              EvalOut
+                { evalStatus = Failure
+                , evalResult = displayError err
+                , evalState = state
+                , evalPager = ""
+                , evalComms = []
                 }
-  else
-    let options = mapMaybe findOption $ words opts
-        updater = foldl' (.) id $ map getUpdateKernelState options in
-      return EvalOut {
-        evalStatus = Success,
-        evalResult = mempty,
-        evalState = updater state,
-        evalPager = "",
-        evalComms = []
+    else let options = mapMaybe findOption $ words opts
+             updater = foldl' (.) id $ map getUpdateKernelState options
+         in return
+              EvalOut
+                { evalStatus = Success
+                , evalResult = mempty
+                , evalState = updater state
+                , evalPager = ""
+                , evalComms = []
                 }
+
   where
     optionExists = isJust . findOption
     findOption opt =
@@ -538,7 +548,7 @@ evalCommand a (Directive SetOption opts) state = do
 
 evalCommand _ (Directive GetType expr) state = wrapExecution state $ do
   write state $ "Type: " ++ expr
-  formatType <$> ((expr ++ " :: ") ++ ) <$> getType expr
+  formatType <$> ((expr ++ " :: ") ++) <$> getType expr
 
 evalCommand _ (Directive GetKind expr) state = wrapExecution state $ do
   write state $ "Kind: " ++ expr
@@ -651,8 +661,6 @@ evalCommand publish (Directive ShellCmd ('!':cmd)) state = wrapExecution state $
           pipe <- fdToHandle readEnd
           return (pipe, handle)
 #endif
-
-
 -- This is taken largely from GHCi's info section in InteractiveUI.
 evalCommand _ (Directive GetHelp _) state = do
   write state "Help via :help or :?."
@@ -895,13 +903,9 @@ evalCommand output (Expression expr) state = do
                   state' = state { openComms = newComms }
 
               -- Store the fact that we should start this comm.
-              return evalOut
-                  { evalComms = CommInfo
-                                  widget
-                                  uuid
-                                  (targetName
-                                    widget) : evalComms
+              return
                 evalOut
+                  { evalComms = CommInfo widget uuid (targetName widget) : evalComms evalOut
                   , evalState = state'
                   }
 
@@ -916,7 +920,8 @@ evalCommand output (Expression expr) state = do
         postprocess (DisplayData MimeHtml _) = html $ printf
                                                         fmt
                                                         unshowableType
-                                                        (formatErrorWithClass "err-msg collapse" text)
+                                                        (formatErrorWithClass "err-msg collapse"
+                                                           text)
                                                         script
           where
             fmt = "<div class='collapse-group'><span class='btn btn-default' href='#' id='unshowable'>Unshowable:<span class='show-type'>%s</span></span>%s</div><script>%s</script>"
@@ -999,7 +1004,6 @@ hoogleResults state results =
 -- Read from a file handle until we hit a delimiter or until we've read as many characters as
 -- requested
 readChars :: Handle -> String -> Int -> IO String
-
 -- If we're done reading, return nothing.
 readChars handle delims 0 = return []
 
@@ -1017,7 +1021,6 @@ readChars handle delims nchars = do
     -- An error occurs at the end of the stream, so just stop reading.
     Left _ -> return []
 
-
 doLoadModule :: String -> String -> Ghc Display
 doLoadModule name modName = do
   -- Remember which modules we've loaded before.
@@ -1054,12 +1057,6 @@ doLoadModule name modName = do
       Failed    -> return $ displayError $ "Failed to load module " ++ modName
 
   where
-#if MIN_VERSION_ghc(7,8,0)
-    objTarget flags = defaultObjectTarget $ targetPlatform flags
-#else
-    objTarget flags = defaultObjectTarget
-#endif
-
     unload :: [InteractiveImport] -> SomeException -> Ghc Display
     unload imported exception = do
       print $ show exception
@@ -1069,14 +1066,18 @@ doLoadModule name modName = do
 
       -- Switch to interpreted mode!
       flags <- getSessionDynFlags
-      setSessionDynFlags flags{ hscTarget = HscInterpreted }
+      setSessionDynFlags flags { hscTarget = HscInterpreted }
 
       -- Return to old context, make sure we have `it`.
       setContext imported
       initializeItVariable
 
       return $ displayError $ "Failed to load module " ++ modName ++ ": " ++ show exception
-
+#if MIN_VERSION_ghc(7,8,0)
+objTarget flags = defaultObjectTarget $ targetPlatform flags
+#else
+objTarget flags = defaultObjectTarget
+#endif
 keepingItVariable :: Interpreter a -> Interpreter a
 keepingItVariable act = do
   -- Generate the it variable temp name
@@ -1095,8 +1096,8 @@ capturedStatement :: (String -> IO ())         -- ^ Function used to publish int
                   -> String                            -- ^ Statement to evaluate.
                   -> Interpreter (String, RunResult)   -- ^ Return the output and result.
 capturedStatement output stmt = do
-  -- Generate random variable names to use so that we cannot accidentally
-  -- override the variables by using the right names in the terminal.
+  -- Generate random variable names to use so that we cannot accidentally override the variables by
+  -- using the right names in the terminal.
   gen <- liftIO getStdGen
   let 
       -- Variable names generation.
@@ -1141,32 +1142,27 @@ capturedStatement output stmt = do
   -- Initialize evaluation context.
   void $ forM initStmts goStmt
 
-  -- Get the pipe to read printed output from.
-  -- This is effectively the source code of dynCompileExpr from GHC API's
-  -- InteractiveEval. However, instead of using a `Dynamic` as an
-  -- intermediary, it just directly reads the value. This is incredibly
-  -- unsafe! However, for some reason the `getContext` and `setContext`
-  -- required by dynCompileExpr (to import and clear Data.Dynamic) cause
-  -- issues with data declarations being updated (e.g. it drops newer
-  -- versions of data declarations for older ones for unknown reasons).
-  -- First, compile down to an HValue.
+  -- Get the pipe to read printed output from. This is effectively the source code of dynCompileExpr
+  -- from GHC API's InteractiveEval. However, instead of using a `Dynamic` as an intermediary, it just
+  -- directly reads the value. This is incredibly unsafe! However, for some reason the `getContext`
+  -- and `setContext` required by dynCompileExpr (to import and clear Data.Dynamic) cause issues with
+  -- data declarations being updated (e.g. it drops newer versions of data declarations for older ones
+  -- for unknown reasons). First, compile down to an HValue.
   Just (_, hValues, _) <- withSession $ liftIO . flip hscStmt pipeExpr
   -- Then convert the HValue into an executable bit, and read the value.
   pipe <- liftIO $ do
             fd <- head <$> unsafeCoerce hValues
             fdToHandle fd
 
-  -- Read from a file handle until we hit a delimiter or until we've read
-  -- as many characters as requested
-  let
-    readChars :: Handle -> String -> Int -> IO String
+  -- Read from a file handle until we hit a delimiter or until we've read as many characters as
+  -- requested
+  let readChars :: Handle -> String -> Int -> IO String
 
       -- If we're done reading, return nothing.
       readChars handle delims 0 = return []
 
       readChars handle delims nchars = do
-      -- Try reading a single character. It will throw an exception if the
-      -- handle is already closed.
+        -- Try reading a single character. It will throw an exception if the handle is already closed.
         tryRead <- gtry $ hGetChar handle :: IO (Either SomeException Char)
         case tryRead of
           Right char ->
@@ -1175,7 +1171,7 @@ capturedStatement output stmt = do
               then return [char]
               else do
                 next <- readChars handle delims (nchars - 1)
-            return $ char:next
+                return $ char : next
           -- An error occurs at the end of the stream, so just stop reading.
           Left _ -> return []
 
@@ -1187,8 +1183,8 @@ capturedStatement output stmt = do
 
   -- Start a loop to publish intermediate results.
   let 
-    -- Compute how long to wait between reading pieces of the output.
-    -- `threadDelay` takes an argument of microseconds.
+      -- Compute how long to wait between reading pieces of the output. `threadDelay` takes an
+      -- argument of microseconds.
       ms = 1000
       delay = 100 * ms
 
@@ -1229,9 +1225,8 @@ capturedStatement output stmt = do
               -- Finalize evaluation context.
               void $ forM postStmts goStmt
 
-    -- Once context is finalized, reading can finish.
-    -- Wait for reading to finish to that the output accumulator is
-    -- completely filled.
+              -- Once context is finalized, reading can finish. Wait for reading to finish to that the output
+              -- accumulator is completely filled.
               liftIO $ takeMVar finishedReading
 
   printedOutput <- liftIO $ readMVar outputAccum
@@ -1257,7 +1252,6 @@ formatErrorWithClass cls =
       startswith "No instance for (Show" err &&
       isInfixOf " arising from a use of `print'" err
 
-
 formatParseError :: StringLoc -> String -> ErrMsg
 formatParseError (Loc line col) =
   printf "Parse error (line %d, column %d): %s" line col

src/IHaskell/Eval/Hoogle.hs

@@ -128,7 +128,6 @@ render HTML = renderHtml
 
 -- | Render a Hoogle result to plain text.
 renderPlain :: HoogleResult -> String
-
 renderPlain (NoResult res) =
   "No response available: " ++ res
 

src/IHaskell/Eval/Lint.hs

@@ -194,7 +194,6 @@ htmlSuggestions = concatMap toHtml
     floating :: String -> String -> String
     floating dir thing = [i| <div class="suggestion-row" style="float: ${dir};">${thing}</div> |]
 
-
 showSuggestion :: String -> String
 showSuggestion = remove lintIdent . dropDo
   where

src/IHaskell/Eval/Parser.hs

@@ -225,7 +225,6 @@ joinFunctions blocks =
     conjoin :: [CodeBlock] -> CodeBlock
     conjoin = Declaration . intercalate "\n" . map str
 
-
 -- | Parse a pragma of the form {-# LANGUAGE ... #-}
 parsePragma :: String       -- ^ Pragma string.
             -> Int          -- ^ Line number at which the directive appears.
@@ -245,7 +244,6 @@ parsePragma ('{':'-':'#':pragma) line =
 parseDirective :: String       -- ^ Directive string.
                -> Int          -- ^ Line number at which the directive appears.
                -> CodeBlock    -- ^ Directive code block or a parse error.
-
 parseDirective (':':'!':directive) line = Directive ShellCmd $ '!' : directive
 parseDirective (':':directive) line =
   case find rightDirective directives of

src/IHaskell/Eval/Util.hs

@@ -72,12 +72,11 @@ extensionFlag ext =
 
     -- Check if a FlagSpec matches "No<ExtensionName>". In that case, we disable the extension.
     flagMatchesNo ext fs = ext == "No" ++ flagSpecName fs
-
 #if !MIN_VERSION_ghc(7,10,0)
 flagSpecName (name, _, _) = name
+
 flagSpecFlag (_, flag, _) = flag
 #endif
-
 -- | Pretty-print dynamic flags (taken from 'InteractiveUI' module of `ghc-bin`)
 pprDynFlags :: Bool       -- ^ Whether to include flags which are on by default
             -> DynFlags
@@ -111,17 +110,20 @@ pprDynFlags show_all dflags =
     default_dflags = defaultDynFlags (settings dflags)
     
     fstr str = text "-f" <> text str
+    
     fnostr str = text "-fno-" <> text str
     
     (ghciFlags, others) = partition (\f -> flagSpecFlag f `elem` flgs) DynFlags.fFlags
+    
     flgs = concat [flgs1, flgs2, flgs3]
+    
     flgs1 = [Opt_PrintExplicitForalls]
 #if MIN_VERSION_ghc(7,8,0)
     flgs2 = [Opt_PrintExplicitKinds]
 #else
     flgs2 = []
 #endif
-    flgs3 = [Opt_PrintBindResult, Opt_BreakOnException, Opt_BreakOnError, Opt_PrintEvldWithShow]
+flgs3 = [Opt_PrintBindResult, Opt_BreakOnException, Opt_BreakOnError, Opt_PrintEvldWithShow]
 
 -- | Pretty-print the base language and active options (taken from `InteractiveUI` module of
 -- `ghc-bin`)
@@ -319,7 +321,6 @@ cleanUpDuplicateInstances = modifySession $ \hscEnv ->
 #else
     instEq _ _ = False
 #endif
-
 -- | Get the type of an expression and convert it to a string.
 getType :: GhcMonad m => String -> m String
 getType expr = do

src/IHaskell/Flags.hs

@@ -44,7 +44,6 @@ data LhsStyle string =
          }
   deriving (Eq, Functor, Show)
 
-
 data NotebookFormat = LhsMarkdown
                     | IpynbFile
   deriving (Eq, Show)
@@ -155,6 +154,7 @@ convert = mode "convert" (Args ConvertLhs []) description unnamedArg convertFlag
 
 lhsStyleBird, lhsStyleTex :: LhsStyle String
 lhsStyleBird = LhsStyle "> " "\n<< " "" "" "" ""
+
 lhsStyleTex = LhsStyle "" "" "\\begin{code}" "\\end{code}" "\\begin{verbatim}" "\\end{verbatim}"
 
 ihaskellArgs :: Mode Args

src/IHaskell/IPython.hs

@@ -196,7 +196,6 @@ subHome path = shelly $ do
   home <- unpack <$> fromMaybe "~" <$> get_env "HOME"
   return $ replace "~" home path
 
-
 -- | Get the path to an executable. If it doensn't exist, fail with an error message complaining
 -- about it.
 path :: Text -> Sh FilePath

src/IHaskell/Types.hs

@@ -41,8 +41,8 @@ import           IHaskell.IPython.Kernel
 
 -- | A class for displayable Haskell types.
 --
--- IHaskell's displaying of results behaves as if these two
--- overlapping/undecidable instances also existed:
+-- IHaskell's displaying of results behaves as if these two overlapping/undecidable instances also
+-- existed:
 -- 
 -- > instance (Show a) => IHaskellDisplay a
 -- > instance Show a where shows _ = id
@@ -51,12 +51,10 @@ class IHaskellDisplay a where
 
 -- | Display as an interactive widget.
 class IHaskellDisplay a => IHaskellWidget a where
-  -- | Output target name for this widget.
-  -- The actual input parameter should be ignored.
+  -- | Output target name for this widget. The actual input parameter should be ignored.
   targetName :: a -> String
 
-  -- | Called when the comm is opened. Allows additional messages to be sent
-  -- after comm open.
+  -- | Called when the comm is opened. Allows additional messages to be sent after comm open.
   open :: a               -- ^ Widget to open a comm port with.
        -> (Value -> IO ()) -- ^ Way to respond to the message.
        -> IO ()
@@ -90,12 +88,12 @@ instance IHaskellWidget Widget where
 instance Show Widget where
   show _ = "<Widget>"
 
-
 -- | Wrapper for ipython-kernel's DisplayData which allows sending multiple results from the same
 -- expression.
 data Display = Display [DisplayData]
              | ManyDisplay [Display]
   deriving (Show, Typeable, Generic)
+
 instance Serialize Display
 
 instance Monoid Display where
@@ -103,7 +101,7 @@ instance Monoid Display where
   ManyDisplay a `mappend` ManyDisplay b = ManyDisplay (a ++ b)
   ManyDisplay a `mappend` b = ManyDisplay (a ++ [b])
   a `mappend` ManyDisplay b = ManyDisplay (a : b)
-    a             `mappend` b             = ManyDisplay [a,b]
+  a `mappend` b = ManyDisplay [a, b]
 
 instance Semigroup Display where
   a <> b = a `mappend` b

src/Main.hs

@@ -196,7 +196,6 @@ createReplyHeader parent = do
 
 -- | Compute a reply to a message.
 replyTo :: ZeroMQInterface -> Message -> MessageHeader -> KernelState -> Interpreter (KernelState, Message)
-
 -- Reply to kernel info requests with a kernel info reply. No computation needs to be done, as a
 -- kernel info reply is a static object (all info is hard coded into the representation of that
 -- message type).
@@ -214,10 +213,9 @@ replyTo interface ShutdownRequest { restartPending = restartPending } replyHeade
   writeChan (shellReplyChannel interface) $ ShutdownReply replyHeader restartPending
   exitSuccess
 
--- Reply to an execution request. The reply itself does not require
--- computation, but this causes messages to be sent to the IOPub socket
--- with the output of the code in the execution request.
-replyTo interface req@ExecuteRequest{ getCode = code } replyHeader state = do
+-- Reply to an execution request. The reply itself does not require computation, but this causes
+-- messages to be sent to the IOPub socket with the output of the code in the execution request.
+replyTo interface req@ExecuteRequest { getCode = code } replyHeader state = do
   -- Convenience function to send a message to the IOPub socket.
   let send msg = liftIO $ writeChan (iopubChannel interface) msg
 
@@ -225,18 +223,16 @@ replyTo interface req@ExecuteRequest{ getCode = code } replyHeader state = do
   dir <- liftIO getIHaskellDir
   liftIO $ Stdin.recordParentHeader dir $ header req
 
-  -- Notify the frontend that the kernel is busy computing.
-  -- All the headers are copies of the reply header with a different
-  -- message type, because this preserves the session ID, parent header,
-  -- and other important information.
+  -- Notify the frontend that the kernel is busy computing. All the headers are copies of the reply
+  -- header with a different message type, because this preserves the session ID, parent header, and
+  -- other important information.
   busyHeader <- liftIO $ dupHeader replyHeader StatusMessage
   send $ PublishStatus busyHeader Busy
 
-  -- Construct a function for publishing output as this is going.
-  -- This function accepts a boolean indicating whether this is the final
-  -- output and the thing to display. Store the final outputs in a list so
-  -- that when we receive an updated non-final output, we can clear the
-  -- entire output and re-display with the updated output.
+  -- Construct a function for publishing output as this is going. This function accepts a boolean
+  -- indicating whether this is the final output and the thing to display. Store the final outputs in
+  -- a list so that when we receive an updated non-final output, we can clear the entire output and
+  -- re-display with the updated output.
   displayed <- liftIO $ newMVar []
   updateNeeded <- liftIO $ newMVar False
   pagerOutput <- liftIO $ newMVar ""
@@ -271,9 +267,10 @@ replyTo interface req@ExecuteRequest{ getCode = code } replyHeader state = do
 
       publish :: EvaluationResult -> IO ()
       publish result = do
-        let final = case result of
-                      IntermediateResult {} -> False
-                      FinalResult {} -> True
+        let final =
+              case result of
+                IntermediateResult{} -> False
+                FinalResult{}        -> True
             outs = outputs result
 
         -- If necessary, clear all previous output and redraw.
@@ -286,12 +283,11 @@ replyTo interface req@ExecuteRequest{ getCode = code } replyHeader state = do
         -- Draw this message.
         sendOutput outs
 
-        -- If this is the final message, add it to the list of completed
-        -- messages. If it isn't, make sure we clear it later by marking
-        -- update needed as true.
+        -- If this is the final message, add it to the list of completed messages. If it isn't, make sure we
+        -- clear it later by marking update needed as true.
         modifyMVar_ updateNeeded (const $ return $ not final)
         when final $ do
-          modifyMVar_ displayed (return . (outs:))
+          modifyMVar_ displayed (return . (outs :))
 
           -- Start all comms that need to be started.
           mapM_ startComm $ startComms result
@@ -319,11 +315,12 @@ replyTo interface req@ExecuteRequest{ getCode = code } replyHeader state = do
   pager <- if usePager state
              then liftIO $ readMVar pagerOutput
              else return ""
-  return (updatedState, ExecuteReply {
-    header = replyHeader,
-    pagerOutput = pager,
-    executionCounter = execCount,
-    status = Ok
+  return
+    (updatedState, ExecuteReply
+                     { header = replyHeader
+                     , pagerOutput = pager
+                     , executionCounter = execCount
+                     , status = Ok
                      })
 
 
@@ -352,10 +349,10 @@ replyTo _ ObjectInfoRequest { objectName = oname } replyHeader state = do
 
 -- TODO: Implement history_reply.
 replyTo _ HistoryRequest{} replyHeader state = do
-  let reply = HistoryReply {
-                header = replyHeader,
+  let reply = HistoryReply
+        { header = replyHeader
         -- FIXME
-                historyReply = []
+        , historyReply = []
         }
   return (state, reply)
 

verify_formatting.py

@@ -14,6 +14,11 @@ def hindent(contents):
 
 
 def diff(src1, src2):
+    # Ignore trailing newlines
+    if src1[-1] == "\n":
+        src1 = src1[:-1]
+    if src2[-1] == "\n":
+        src2 = src2[:-1]
 
     with open(".tmp1", "w") as f1:
         f1.write(src1)
@@ -40,8 +45,6 @@ for root, dirnames, filenames in os.walk("src"):
     for filename in filenames:
         if filename.endswith(".hs"):
             sources.append(os.path.join(root, filename))
-            break
-    break
 
 
 hindent_outputs = {}