Improvements to parenthesis checking.

* Only enable the check for codeworld-mode.  Oops!
* Leave blank lines after the warnings, so later console output is readable.

Author: cdsmith

codeworld-compiler/src/Compile.hs

@@ -42,7 +42,9 @@ compileSource src out err mode = checkDangerousSource src >>= \case
             "Sorry, but your program refers to forbidden language features."
         return False
     False -> withSystemTempDirectory "buildSource" $ \tmpdir -> do
-        parenProblem <- not <$> checkParsedCode src err
+        parenProblem <- case mode of
+            "codeworld" -> not <$> checkParsedCode src err
+            _           -> return False
         copyFile src (tmpdir </> "program.hs")
         baseArgs <- case mode of
             "haskell"   -> return haskellCompatibleBuildArgs
@@ -55,9 +57,7 @@ compileSource src out err mode = checkDangerousSource src >>= \case
                         "codeworld" -> filterOutput output
                         _           -> output
 
-                if parenProblem
-                    then when (not (B.null filteredOutput)) (B.appendFile err "\n\n")
-                    else B.writeFile err ""
+                when (not parenProblem) $ B.writeFile err ""
                 B.appendFile err filteredOutput
 
                 let target = tmpdir </> "program.jsexe"

codeworld-compiler/src/ParseCode.hs

@@ -1,6 +1,3 @@
-{-# LANGUAGE LambdaCase        #-}
-{-# LANGUAGE OverloadedStrings #-}
-
 {-
   Copyright 2017 The CodeWorld Authors. All rights reserved.
 
@@ -19,10 +16,6 @@
 
 module ParseCode (checkParsedCode) where
 
-import qualified Data.ByteString as B
-import           Data.ByteString.Char8 (pack)
-import           Data.List (intercalate)
-import           Data.List.Split (splitOn)
 import           Data.Generics
 import           Language.Haskell.Exts
 
@@ -32,7 +25,7 @@ checkParsedCode src err = do
     case result of
         ParseOk mod -> case getErrors mod of
             [] -> return True
-            errors -> writeFile err (intercalate "\n\n" errors) >> return False
+            errors -> writeFile err (concatMap (++ "\n\n") errors) >> return False
         ParseFailed _ _ -> return True
 
 getErrors :: Module SrcSpanInfo -> [String]
@@ -70,6 +63,7 @@ isGoodPatRhs (PTuple _ _ _) = True
 isGoodPatRhs _              = False
 
 formatLocation :: SrcSpanInfo -> String
-formatLocation (SrcSpanInfo s _) = "program.hs" ++ ":" ++ show line ++ ":" ++ show col ++ ": "
+formatLocation (SrcSpanInfo s _) =
+        "program.hs" ++ ":" ++ show line ++ ":" ++ show col ++ ": "
     where line = srcSpanStartLine s
           col = srcSpanStartColumn s