version 0.5.50.5.5

26 files changed, 190 insertions, 85 deletions

diff --git a/examples/failing/DuplicateTypeVars.purs b/examples/failing/DuplicateTypeVars.purs
new file mode 100644
index 0000000..15340f0
--- /dev/null
+++ b/examples/failing/DuplicateTypeVars.purs
@@ -0,0 +1,3 @@
+module Main where
+
+type Foo a a = a
diff --git a/examples/failing/TopLevelCaseNoArgs.purs b/examples/failing/TopLevelCaseNoArgs.purs
new file mode 100644
index 0000000..c8979c4
--- /dev/null
+++ b/examples/failing/TopLevelCaseNoArgs.purs
@@ -0,0 +1,4 @@
+module Main where
+  foo :: Number
+  foo = 1
+  foo = 2
diff --git a/examples/passing/DeepArrayBinder.purs b/examples/passing/DeepArrayBinder.purs
new file mode 100644
index 0000000..5ed5726
--- /dev/null
+++ b/examples/passing/DeepArrayBinder.purs
@@ -0,0 +1,16 @@
+module Main where
+
+import Control.Monad.Eff
+
+match2 :: [Number] -> Number
+match2 (x : y : xs) = x * y + match2 xs
+match2 _ = 0
+
+foreign import explode 
+  "function explode() {\
+  \  throw new Error('Incorrect result');\
+  \}" :: forall eff a. Eff eff a
+
+main = case match2 [1, 2, 3, 4, 5, 6, 7, 8, 9] of
+  100 -> Debug.Trace.trace "Done"
+  _ -> explode
diff --git a/examples/passing/NegativeBinder.purs b/examples/passing/NegativeBinder.purs
new file mode 100644
index 0000000..d5dfe1b
--- /dev/null
+++ b/examples/passing/NegativeBinder.purs
@@ -0,0 +1,7 @@
+module Main where
+
+test :: Number -> Boolean
+test -1 = false
+test _  = true
+
+main = Debug.Trace.trace "Done"
diff --git a/examples/passing/OperatorAssociativity.purs b/examples/passing/OperatorAssociativity.purs
new file mode 100644
index 0000000..e0036c5
--- /dev/null
+++ b/examples/passing/OperatorAssociativity.purs
@@ -0,0 +1,15 @@
+module Main where
+
+import Control.Monad.Eff
+
+bug :: Number -> Number -> Number
+bug a b = 0 - (a - b)
+
+foreign import explode 
+  "function explode() {\
+  \  throw new Error('Assertion failed!');\
+  \}":: forall eff a. Eff eff a
+
+main = case bug 0 2 of
+  2 -> Debug.Trace.trace "Done!"
+  _ -> explode
diff --git a/prelude/prelude.purs b/prelude/prelude.purs
index 1c1788f..1043e07 100644
--- a/prelude/prelude.purs
+++ b/prelude/prelude.purs
@@ -923,7 +923,7 @@ module Control.Monad.ST where
                              \      return arr[i];\
                              \    };\
                              \  };\
-                             \}" :: forall a h r. STArray h a -> Eff (st :: ST h | r) a
+                             \}" :: forall a h r. STArray h a -> Number -> Eff (st :: ST h | r) a
 
   foreign import pokeSTArray "function pokeSTArray(arr) {\
                              \  return function(i) {\
diff --git a/psc-make/Main.hs b/psc-make/Main.hs
index bb0ecb0..e8c936d 100644
--- a/psc-make/Main.hs
+++ b/psc-make/Main.hs
@@ -34,9 +34,6 @@ import qualified Language.PureScript as P
 import qualified Paths_purescript as Paths
 import qualified System.IO.UTF8 as U
 
-preludeFilename :: IO FilePath
-preludeFilename = Paths.getDataFileName "prelude/prelude.purs"
-
 readInput :: [FilePath] -> IO (Either ParseError [(FilePath, P.Module)])
 readInput input = fmap collect $ forM input $ \inputFile -> do
   text <- U.readFile inputFile
@@ -69,21 +66,28 @@ instance P.MonadMake Make where
   liftError = either throwError return
   progress = makeIO . U.putStrLn
 
-compile :: FilePath -> P.Options -> [FilePath] -> IO ()
-compile outputDir opts input = do
-  modules <- readInput input
+compile :: FilePath -> [FilePath] -> FilePath -> P.Options -> Bool -> IO ()
+compile prelude input outputDir opts usePrefix = do
+  modules <- readInput allInputFiles
   case modules of
     Left err -> do
       U.print err
       exitFailure
     Right ms -> do
-      e <- runMake $ P.make outputDir opts ms
+      e <- runMake $ P.make outputDir opts ms prefix
       case e of
         Left err -> do
           U.putStrLn err
           exitFailure
         Right _ -> do
           exitSuccess
+  where 
+    prefix = if usePrefix
+               then ["Generated by psc-make version " ++ showVersion Paths.version]
+               else []
+
+    allInputFiles | P.optionsNoPrelude opts = input
+                  | otherwise = prelude : input
 
 mkdirp :: FilePath -> IO ()
 mkdirp = createDirectoryIfMissing True . takeDirectory
@@ -123,14 +127,12 @@ verboseErrors = value $ flag $ (optInfo [ "v", "verbose-errors" ])
 options :: Term P.Options
 options = P.Options <$> noPrelude <*> noTco <*> performRuntimeTypeChecks <*> noMagicDo <*> pure Nothing <*> noOpts <*> pure Nothing <*> pure [] <*> pure [] <*> verboseErrors
 
-inputFilesAndPrelude :: FilePath -> Term [FilePath]
-inputFilesAndPrelude prelude = combine <$> (not <$> noPrelude) <*> inputFiles
-  where
-  combine True input = prelude : input
-  combine False input = input
+noPrefix :: Term Bool
+noPrefix = value $ flag $ (optInfo ["p", "no-prefix" ])
+     { optDoc = "Do not include comment header"}
 
 term :: FilePath -> Term (IO ())
-term prelude = compile <$> outputDirectory <*> options <*> inputFilesAndPrelude prelude
+term prelude = compile prelude <$> inputFiles <*> outputDirectory <*> options <*> (not <$> noPrefix)
 
 termInfo :: TermInfo
 termInfo = defTI
@@ -141,5 +143,5 @@ termInfo = defTI
 
 main :: IO ()
 main = do
-  prelude <- preludeFilename
+  prelude <- P.preludeFilename
   run (term prelude, termInfo)
diff --git a/psc/Main.hs b/psc/Main.hs
index e70b068..438facd 100644
--- a/psc/Main.hs
+++ b/psc/Main.hs
@@ -33,9 +33,6 @@ import qualified Language.PureScript as P
 import qualified Paths_purescript as Paths
 import qualified System.IO.UTF8 as U
 
-preludeFilename :: IO FilePath
-preludeFilename = Paths.getDataFileName "prelude/prelude.purs"
-
 readInput :: Maybe [FilePath] -> IO (Either ParseError [(FilePath, P.Module)])
 readInput Nothing = do
   text <- getContents
@@ -47,15 +44,15 @@ readInput (Just input) = fmap collect $ forM input $ \inputFile -> do
   collect :: [(FilePath, Either ParseError [P.Module])] -> Either ParseError [(FilePath, P.Module)]
   collect = fmap concat . sequence . map (\(fp, e) -> fmap (map ((,) fp)) e)
 
-compile :: P.Options -> Maybe [FilePath] -> Maybe FilePath -> Maybe FilePath -> IO ()
-compile opts input output externs = do
-  modules <- readInput input
+compile :: FilePath -> P.Options -> Bool -> [FilePath] -> Maybe FilePath -> Maybe FilePath -> Bool -> IO ()
+compile prelude opts stdin input output externs usePrefix = do
+  modules <- readInput stdInOrInputFiles
   case modules of
     Left err -> do
       U.hPutStr stderr $ show err
       exitFailure
     Right ms -> do
-      case P.compile opts (map snd ms) of
+      case P.compile opts (map snd ms) prefix of
         Left err -> do
           U.hPutStrLn stderr err
           exitFailure
@@ -67,6 +64,14 @@ compile opts input output externs = do
             Just path -> mkdirp path >> U.writeFile path exts
             Nothing -> return ()
           exitSuccess
+  where
+  stdInOrInputFiles :: Maybe [FilePath]
+  stdInOrInputFiles | stdin = Nothing
+                    | P.optionsNoPrelude opts = Just input
+                    | otherwise = Just $ prelude : input
+  prefix = if usePrefix
+              then ["Generated by psc version " ++ showVersion Paths.version]                    
+              else []
 
 mkdirp :: FilePath -> IO ()
 mkdirp = createDirectoryIfMissing True . takeDirectory
@@ -127,18 +132,15 @@ verboseErrors :: Term Bool
 verboseErrors = value $ flag $ (optInfo [ "v", "verbose-errors" ])
      { optDoc = "Display verbose error messages" }
 
+noPrefix :: Term Bool
+noPrefix = value $ flag $ (optInfo ["no-prefix" ])
+     { optDoc = "Do not include comment header"}
+
 options :: Term P.Options
 options = P.Options <$> noPrelude <*> noTco <*> performRuntimeTypeChecks <*> noMagicDo <*> runMain <*> noOpts <*> (Just <$> browserNamespace) <*> dceModules <*> codeGenModules <*> verboseErrors
 
-stdInOrInputFiles :: FilePath -> Term (Maybe [FilePath])
-stdInOrInputFiles prelude = combine <$> useStdIn <*> (not <$> noPrelude) <*> inputFiles
-  where
-  combine False True input = Just (prelude : input)
-  combine False False input = Just input
-  combine True _ _ = Nothing
-
 term :: FilePath -> Term (IO ())
-term prelude = compile <$> options <*> stdInOrInputFiles prelude <*> outputFile <*> externsFile
+term prelude = compile prelude <$> options <*> useStdIn <*> inputFiles <*> outputFile <*> externsFile <*> (not <$> noPrefix)
 
 termInfo :: TermInfo
 termInfo = defTI
@@ -149,6 +151,6 @@ termInfo = defTI
 
 main :: IO ()
 main = do
-  prelude <- preludeFilename
+  prelude <- P.preludeFilename
   run (term prelude, termInfo)
 
diff --git a/psci/Main.hs b/psci/Main.hs
index 99d68e4..c05908e 100644
--- a/psci/Main.hs
+++ b/psci/Main.hs
@@ -117,12 +117,6 @@ getHistoryFilename :: IO FilePath
 getHistoryFilename = getUserConfigFile "purescript" "psci_history"
 
 -- |
--- Grabs the filename where prelude is.
---
-getPreludeFilename :: IO FilePath
-getPreludeFilename = Paths.getDataFileName "prelude/prelude.purs"
-
--- |
 -- Loads a file for use with imports.
 --
 loadModule :: FilePath -> IO (Either String [P.Module])
@@ -282,7 +276,7 @@ handleDeclaration :: P.Expr -> PSCI ()
 handleDeclaration value = do
   st <- PSCI $ lift get
   let m = createTemporaryModule True st value
-  e <- psciIO . runMake $ P.make modulesDir options (psciLoadedModules st ++ [("$PSCI.purs", m)])
+  e <- psciIO . runMake $ P.make modulesDir options (psciLoadedModules st ++ [("$PSCI.purs", m)]) [] 
   case e of
     Left err -> PSCI $ outputStrLn err
     Right _ -> do
@@ -301,7 +295,7 @@ handleTypeOf :: P.Expr -> PSCI ()
 handleTypeOf value = do
   st <- PSCI $ lift get
   let m = createTemporaryModule False st value
-  e <- psciIO . runMake $ P.make modulesDir options (psciLoadedModules st ++ [("$PSCI.purs", m)])
+  e <- psciIO . runMake $ P.make modulesDir options (psciLoadedModules st ++ [("$PSCI.purs", m)]) [] 
   case e of
     Left err -> PSCI $ outputStrLn err
     Right env' ->
@@ -317,7 +311,7 @@ handleKindOf typ = do
   st <- PSCI $ lift get
   let m = createTemporaryModuleForKind st typ
       mName = P.ModuleName [P.ProperName "$PSCI"]
-  e <- psciIO . runMake $ P.make modulesDir options (psciLoadedModules st ++ [("$PSCI.purs", m)])
+  e <- psciIO . runMake $ P.make modulesDir options (psciLoadedModules st ++ [("$PSCI.purs", m)]) [] 
   case e of
     Left err -> PSCI $ outputStrLn err
     Right env' ->
@@ -400,7 +394,7 @@ loadUserConfig = do
 loop :: [FilePath] -> IO ()
 loop files = do
   config <- loadUserConfig
-  preludeFilename <- getPreludeFilename
+  preludeFilename <- P.preludeFilename
   filesAndModules <- mapM (\file -> fmap (fmap (map ((,) file))) . loadModule $ file) (preludeFilename : files)
   let modulesOrFirstError = fmap concat $ sequence filesAndModules
   case modulesOrFirstError of
diff --git a/purescript.cabal b/purescript.cabal
index 5d683da..0022710 100644
--- a/purescript.cabal
+++ b/purescript.cabal
@@ -1,5 +1,5 @@
 name: purescript
-version: 0.5.4.1
+version: 0.5.5
 cabal-version: >=1.8
 build-type: Custom
 license: MIT
@@ -88,7 +88,7 @@ library
     exposed: True
     buildable: True
     hs-source-dirs: src
-    other-modules:
+    other-modules: Paths_purescript
     ghc-options: -Wall -O2
 
 executable psc
diff --git a/src/Language/PureScript.hs b/src/Language/PureScript.hs
index c2b2872..fb7eb5c 100644
--- a/src/Language/PureScript.hs
+++ b/src/Language/PureScript.hs
@@ -13,7 +13,7 @@
 --
 -----------------------------------------------------------------------------
 
-module Language.PureScript (module P, compile, compile', MonadMake(..), make) where
+module Language.PureScript (module P, compile, compile', MonadMake(..), make, preludeFilename) where
 
 import Language.PureScript.Types as P
 import Language.PureScript.Kinds as P
@@ -34,6 +34,7 @@ import Language.PureScript.Supply as P
 import Language.PureScript.Renamer as P
 
 import qualified Language.PureScript.Constants as C
+import qualified Paths_purescript as Paths
 
 import Data.List (find, sortBy, groupBy, intercalate)
 import Data.Time.Clock
@@ -66,11 +67,11 @@ import System.FilePath (pathSeparator)
 --
 --  * Pretty-print the generated Javascript
 --
-compile :: Options -> [Module] -> Either String (String, String, Environment)
+compile :: Options -> [Module] -> [String] -> Either String (String, String, Environment)
 compile = compile' initEnvironment
 
-compile' :: Environment -> Options -> [Module] -> Either String (String, String, Environment)
-compile' env opts ms = do
+compile' :: Environment -> Options -> [Module] -> [String] -> Either String (String, String, Environment)
+compile' env opts ms prefix = do
   (sorted, _) <- sortModules $ map importPrim $ if optionsNoPrelude opts then ms else (map importPrelude ms)
   (desugared, nextVar) <- stringifyErrorStack True $ runSupplyT 0 $ desugar sorted
   (elaborated, env') <- runCheck' opts env $ forM desugared $ typeCheckModule mainModuleIdent
@@ -83,7 +84,8 @@ compile' env opts ms = do
   let js = evalSupply nextVar $ concat <$> mapM (\m -> moduleToJs Globals opts m env') modulesToCodeGen
   let exts = intercalate "\n" . map (`moduleToPs` env') $ modulesToCodeGen
   js' <- generateMain env' opts js
-  return (prettyPrintJS js', exts, env')
+  let pjs = unlines $ map ("// " ++) prefix ++ [prettyPrintJS js']
+  return (pjs, exts, env')
   where
   mainModuleIdent = moduleNameFromString <$> optionsMain opts
 
@@ -168,8 +170,8 @@ class MonadMake m where
 -- If timestamps have not changed, the externs file can be used to provide the module's types without
 -- having to typecheck the module again.
 --
-make :: (Functor m, Applicative m, Monad m, MonadMake m) => FilePath -> Options -> [(FilePath, Module)] -> m Environment
-make outputDir opts ms = do
+make :: (Functor m, Applicative m, Monad m, MonadMake m) => FilePath -> Options -> [(FilePath, Module)] -> [String] -> m Environment
+make outputDir opts ms prefix = do
   let filePathMap = M.fromList (map (\(fp, Module mn _ _) -> (mn, fp)) ms)
 
   (sorted, graph) <- liftError $ sortModules $ map importPrim $ if optionsNoPrelude opts then map snd ms else (map (importPrelude . snd) ms)
@@ -216,8 +218,9 @@ make outputDir opts ms = do
     let mod' = Module moduleName' regrouped exps
     let [renamed] = renameInModules [mod'] 
 
-    js <- prettyPrintJS <$> moduleToJs CommonJS opts renamed env'
-    let exts = moduleToPs renamed env'
+    pjs <- prettyPrintJS <$> moduleToJs CommonJS opts renamed env'
+    let js = unlines $ map ("// " ++) prefix ++ [pjs]
+    let exts = unlines $ map ("-- " ++ ) prefix ++ [moduleToPs renamed env']
 
     lift $ writeTextFile jsFile js
     lift $ writeTextFile externsFile exts
@@ -261,3 +264,6 @@ importPrim = addDefaultImport (ModuleName [ProperName C.prim])
 
 importPrelude :: Module -> Module
 importPrelude = addDefaultImport (ModuleName [ProperName C.prelude])
+
+preludeFilename :: IO FilePath
+preludeFilename = Paths.getDataFileName "prelude/prelude.purs"
diff --git a/src/Language/PureScript/CodeGen/JS.hs b/src/Language/PureScript/CodeGen/JS.hs
index 47a0703..5faf3e8 100644
--- a/src/Language/PureScript/CodeGen/JS.hs
+++ b/src/Language/PureScript/CodeGen/JS.hs
@@ -27,7 +27,7 @@ import Data.Maybe (catMaybes, fromJust)
 import Data.Function (on)
 import Data.List (nub, (\\), delete, sortBy)
 
-import Control.Monad (replicateM, forM)
+import Control.Monad (foldM, replicateM, forM)
 import Control.Applicative
 
 import Language.PureScript.Names
@@ -307,6 +307,7 @@ varToJs m qual = qualifiedToJS m id qual
 -- variable that may have a qualified name.
 --
 qualifiedToJS :: ModuleName -> (a -> Ident) -> Qualified a -> JS
+qualifiedToJS _ f (Qualified (Just (ModuleName [ProperName mn])) a) | mn == C.prim = JSVar . runIdent $ f a
 qualifiedToJS m f (Qualified (Just m') a) | m /= m' = accessor (f a) (JSVar (moduleNameToJs m'))
 qualifiedToJS _ f (Qualified _ a) = JSVar $ identToJs (f a)
 
@@ -391,18 +392,27 @@ binderToJs m e varName done (ArrayBinder bs) = do
     done'' <- go done' (index + 1) bs'
     js <- binderToJs m e elVar done'' binder
     return (JSVariableIntroduction elVar (Just (JSIndexer (JSNumericLiteral (Left index)) (JSVar varName))) : js)
-binderToJs m e varName done (ConsBinder headBinder tailBinder) = do
-  headVar <- freshName
+binderToJs m e varName done binder@(ConsBinder _ _) = do
+  let (headBinders, tailBinder) = uncons [] binder
+      numberOfHeadBinders = fromIntegral $ length headBinders
+  js1 <- foldM (\done' (headBinder, index) -> do
+    headVar <- freshName
+    jss <- binderToJs m e headVar done' headBinder
+    return (JSVariableIntroduction headVar (Just (JSIndexer (JSNumericLiteral (Left index)) (JSVar varName))) : jss)) done (zip headBinders [0..])
   tailVar <- freshName
-  js1 <- binderToJs m e headVar done headBinder
   js2 <- binderToJs m e tailVar js1 tailBinder
-  return [JSIfElse (JSBinary GreaterThan (JSAccessor "length" (JSVar varName)) (JSNumericLiteral (Left 0))) (JSBlock
-    ( JSVariableIntroduction headVar (Just (JSIndexer (JSNumericLiteral (Left 0)) (JSVar varName))) :
-      JSVariableIntroduction tailVar (Just (JSApp (JSAccessor "slice" (JSVar varName)) [JSNumericLiteral (Left 1)])) :
+  return [JSIfElse (JSBinary GreaterThanOrEqualTo (JSAccessor "length" (JSVar varName)) (JSNumericLiteral (Left numberOfHeadBinders))) (JSBlock
+    ( JSVariableIntroduction tailVar (Just (JSApp (JSAccessor "slice" (JSVar varName)) [JSNumericLiteral (Left numberOfHeadBinders)])) :
       js2
     )) Nothing]
+  where 
+  uncons :: [Binder] -> Binder -> ([Binder], Binder)
+  uncons acc (ConsBinder h t) = uncons (h : acc) t
+  uncons acc (PositionedBinder _ b) = uncons acc b
+  uncons acc tailBinder = (reverse acc, tailBinder)
 binderToJs m e varName done (NamedBinder ident binder) = do
   js <- binderToJs m e varName done binder
   return (JSVariableIntroduction (identToJs ident) (Just (JSVar varName)) : js)
 binderToJs m e varName done (PositionedBinder _ binder) =
   binderToJs m e varName done binder
+
diff --git a/src/Language/PureScript/Constants.hs b/src/Language/PureScript/Constants.hs
index d2c5a75..b51ed9a 100644
--- a/src/Language/PureScript/Constants.hs
+++ b/src/Language/PureScript/Constants.hs
@@ -153,6 +153,11 @@ mkFn = "mkFn"
 runFn :: String
 runFn = "runFn"
 
+-- Prim values
+
+undefined :: String
+undefined = "undefined"
+
 -- Type Class Dictionary Names
 
 monadEffDictionary :: String
diff --git a/src/Language/PureScript/Optimizer.hs b/src/Language/PureScript/Optimizer.hs
index 9ffc4b0..fb4eacc 100644
--- a/src/Language/PureScript/Optimizer.hs
+++ b/src/Language/PureScript/Optimizer.hs
@@ -57,6 +57,8 @@ optimize opts | optionsNoOptimizations opts = id
   , tco opts
   , magicDo opts
   , removeCodeAfterReturnStatements
+  , removeUnusedArg
+  , removeUndefinedApp
   , unThunk
   , etaConvert
   , evaluateIifes
diff --git a/src/Language/PureScript/Optimizer/Inliner.hs b/src/Language/PureScript/Optimizer/Inliner.hs
index cdcca29..2664afb 100644
--- a/src/Language/PureScript/Optimizer/Inliner.hs
+++ b/src/Language/PureScript/Optimizer/Inliner.hs
@@ -49,8 +49,7 @@ etaConvert = everywhereOnJS convert
       not (any (`isRebound` block) (map JSVar idents)) &&
       not (any (`isRebound` block) args)
       = JSBlock (map (replaceIdents (zip idents args)) body)
-  convert (JSFunction Nothing [arg] (JSBlock [JSReturn (JSApp fn@JSVar{} [JSObjectLiteral []])]))
-    | arg == C.__unused = fn
+  convert (JSFunction Nothing [] (JSBlock [JSReturn (JSApp fn [])])) = fn
   convert js = js
 
 unThunk :: JS -> JS
@@ -59,7 +58,7 @@ unThunk = everywhereOnJS convert
   convert :: JS -> JS
   convert (JSBlock []) = JSBlock []
   convert (JSBlock jss) =
-    case (last jss) of
+    case last jss of
       JSReturn (JSApp (JSFunction Nothing [] (JSBlock body)) []) -> JSBlock $ init jss ++ body
       _ -> JSBlock jss
   convert js = js
@@ -154,7 +153,7 @@ inlineCommonOperators = applyAll $
     convert other = other
     isOp (JSAccessor fnName' (JSVar prelude)) = prelude == C.prelude && fnName' == fnName
     isOp _ = False
-  isOpDict dictName (JSApp (JSAccessor prop (JSVar prelude)) [JSObjectLiteral []]) = prelude == C.prelude && prop == dictName
+  isOpDict dictName (JSApp (JSAccessor prop (JSVar prelude)) []) = prelude == C.prelude && prop == dictName
   isOpDict _ _ = False
   mkFn :: Int -> JS -> JS
   mkFn 0 = everywhereOnJS convert
diff --git a/src/Language/PureScript/Optimizer/MagicDo.hs b/src/Language/PureScript/Optimizer/MagicDo.hs
index 6d27a6b..9571bad 100644
--- a/src/Language/PureScript/Optimizer/MagicDo.hs
+++ b/src/Language/PureScript/Optimizer/MagicDo.hs
@@ -60,7 +60,7 @@ magicDo' = everywhereOnJS undo . everywhereOnJSTopDown convert
   -- Desugar pure
   convert (JSApp (JSApp pure' [val]) []) | isPure pure' = val
   -- Desugar >>
-  convert (JSApp (JSApp bind [m]) [JSFunction Nothing [arg] (JSBlock js)]) | isBind bind && isJSReturn (last js) && arg == C.__unused =
+  convert (JSApp (JSApp bind [m]) [JSFunction Nothing [] (JSBlock js)]) | isBind bind && isJSReturn (last js) =
     let JSReturn ret = last js in
     JSFunction (Just fnName) [] $ JSBlock (JSApp m [] : init js ++ [JSReturn (JSApp ret [])] )
   -- Desugar >>=
@@ -69,10 +69,10 @@ magicDo' = everywhereOnJS undo . everywhereOnJSTopDown convert
     JSFunction (Just fnName) [] $ JSBlock (JSVariableIntroduction arg (Just (JSApp m [])) : init js ++ [JSReturn (JSApp ret [])] )
   -- Desugar untilE
   convert (JSApp (JSApp f [arg]) []) | isEffFunc C.untilE f =
-    JSApp (JSFunction Nothing [] (JSBlock [ JSWhile (JSUnary Not (JSApp arg [])) (JSBlock []), JSReturn (JSObjectLiteral []) ])) []
+    JSApp (JSFunction Nothing [] (JSBlock [ JSWhile (JSUnary Not (JSApp arg [])) (JSBlock []), JSReturn $ JSObjectLiteral []])) []
   -- Desugar whileE
   convert (JSApp (JSApp (JSApp f [arg1]) [arg2]) []) | isEffFunc C.whileE f =
-    JSApp (JSFunction Nothing [] (JSBlock [ JSWhile (JSApp arg1 []) (JSBlock [ JSApp arg2 [] ]), JSReturn (JSObjectLiteral []) ])) []
+    JSApp (JSFunction Nothing [] (JSBlock [ JSWhile (JSApp arg1 []) (JSBlock [ JSApp arg2 [] ]), JSReturn $ JSObjectLiteral []])) []
   convert other = other
   -- Check if an expression represents a monomorphic call to >>= for the Eff monad
   isBind (JSApp bindPoly [effDict]) | isBindPoly bindPoly && isEffDict C.bindEffDictionary effDict = True
@@ -99,8 +99,8 @@ magicDo' = everywhereOnJS undo . everywhereOnJSTopDown convert
   isEffFunc name (JSAccessor name' (JSVar eff)) = eff == C.eff && name == name'
   isEffFunc _ _ = False
   -- Check if an expression represents the Monad Eff dictionary
-  isEffDict name (JSApp (JSVar ident) [JSObjectLiteral []]) | ident == name = True
-  isEffDict name (JSApp (JSAccessor prop (JSVar eff)) [JSObjectLiteral []]) = eff == C.eff && prop == name
+  isEffDict name (JSApp (JSVar ident) []) | ident == name = True
+  isEffDict name (JSApp (JSAccessor prop (JSVar eff)) []) = eff == C.eff && prop == name
   isEffDict _ _ = False
   -- Remove __do function applications which remain after desugaring
   undo :: JS -> JS
diff --git a/src/Language/PureScript/Optimizer/Unused.hs b/src/Language/PureScript/Optimizer/Unused.hs
index c0de762..33a233d 100644
--- a/src/Language/PureScript/Optimizer/Unused.hs
+++ b/src/Language/PureScript/Optimizer/Unused.hs
@@ -13,13 +13,17 @@
 --
 -----------------------------------------------------------------------------
 
-module Language.PureScript.Optimizer.Unused (
-  removeCodeAfterReturnStatements
-) where
+module Language.PureScript.Optimizer.Unused
+  ( removeCodeAfterReturnStatements
+  , removeUnusedArg
+  , removeUndefinedApp
+  ) where
 
 import Language.PureScript.CodeGen.JS.AST
 import Language.PureScript.Optimizer.Common
 
+import qualified Language.PureScript.Constants as C
+
 removeCodeAfterReturnStatements :: JS -> JS
 removeCodeAfterReturnStatements = everywhereOnJS (removeFromBlock go)
   where
@@ -28,3 +32,15 @@ removeCodeAfterReturnStatements = everywhereOnJS (removeFromBlock go)
          | otherwise = let (body, ret : _) = span (not . isJSReturn) jss in body ++ [ret]
   isJSReturn (JSReturn _) = True
   isJSReturn _ = False
+
+removeUnusedArg :: JS -> JS
+removeUnusedArg = everywhereOnJS convert
+  where
+  convert (JSFunction name [arg] body) | arg == C.__unused = JSFunction name [] body
+  convert js = js
+
+removeUndefinedApp :: JS -> JS
+removeUndefinedApp = everywhereOnJS convert
+  where
+  convert (JSApp fn [JSVar arg]) | arg == C.undefined = JSApp fn []
+  convert js = js
diff --git a/src/Language/PureScript/Options.hs b/src/Language/PureScript/Options.hs
index 9aadedb..a271c34 100644
--- a/src/Language/PureScript/Options.hs
+++ b/src/Language/PureScript/Options.hs
@@ -61,6 +61,7 @@ data Options = Options {
     -- Verbose error message
     --
   , optionsVerboseErrors :: Bool
+
   } deriving Show
 
 -- |
diff --git a/src/Language/PureScript/Parser/Declarations.hs b/src/Language/PureScript/Parser/Declarations.hs
index 9c79a55..d226961 100644
--- a/src/Language/PureScript/Parser/Declarations.hs
+++ b/src/Language/PureScript/Parser/Declarations.hs
@@ -24,7 +24,9 @@ module Language.PureScript.Parser.Declarations (
 ) where
 
 import Data.Maybe (isJust, fromMaybe)
+
 import Control.Applicative
+import Control.Arrow ((+++))
 
 import Language.PureScript.Parser.State
 import Language.PureScript.Parser.Common
@@ -365,7 +367,12 @@ parseBooleanBinder :: P.Parsec String ParseState Binder
 parseBooleanBinder = BooleanBinder <$> booleanLiteral
 
 parseNumberBinder :: P.Parsec String ParseState Binder
-parseNumberBinder = NumberBinder <$> C.integerOrFloat
+parseNumberBinder = NumberBinder <$> (C.lexeme sign <*> C.integerOrFloat)
+  where
+  sign :: P.Parsec String ParseState (Either Integer Double -> Either Integer Double)
+  sign = (P.char '-' >> return (negate +++ negate))
+         <|> (P.char '+' >> return id)
+         <|> return id
 
 parseVarBinder :: P.Parsec String ParseState Binder
 parseVarBinder = VarBinder <$> C.parseIdent
diff --git a/src/Language/PureScript/Pretty/Common.hs b/src/Language/PureScript/Pretty/Common.hs
index 014ba38..380d77e 100644
--- a/src/Language/PureScript/Pretty/Common.hs
+++ b/src/Language/PureScript/Pretty/Common.hs
@@ -65,5 +65,5 @@ prettyPrintMany f xs = do
 --
 prettyPrintObjectKey :: String -> String
 prettyPrintObjectKey s | s `elem` reservedPsNames = show s
-                       | head s `elem` opChars = show s
+                       | any (`elem` opChars) s = show s
                        | otherwise = s
diff --git a/src/Language/PureScript/Pretty/JS.hs b/src/Language/PureScript/Pretty/JS.hs
index 7933302..fc4ea0b 100644
--- a/src/Language/PureScript/Pretty/JS.hs
+++ b/src/Language/PureScript/Pretty/JS.hs
@@ -190,7 +190,7 @@ unary op str = Wrap match (++)
     match' _ = Nothing
 
 binary :: BinaryOperator -> String -> Operator PrinterState JS String
-binary op str = AssocR match (\v1 v2 -> v1 ++ " " ++ str ++ " " ++ v2)
+binary op str = AssocL match (\v1 v2 -> v1 ++ " " ++ str ++ " " ++ v2)
   where
   match :: Pattern PrinterState JS (JS, JS)
   match = mkPattern match'
diff --git a/src/Language/PureScript/Sugar/CaseDeclarations.hs b/src/Language/PureScript/Sugar/CaseDeclarations.hs
index 44bd0d3..2a215b8 100644
--- a/src/Language/PureScript/Sugar/CaseDeclarations.hs
+++ b/src/Language/PureScript/Sugar/CaseDeclarations.hs
@@ -87,6 +87,8 @@ toDecls ds@(ValueDeclaration ident _ bs _ _ : _) = do
   let tuples = map toTuple ds
   unless (all ((== length bs) . length . fst) tuples) $
       throwError $ mkErrorStack ("Argument list lengths differ in declaration " ++ show ident) Nothing
+  unless (not $ null bs) $
+      throwError $ mkErrorStack ("Top level case disallowed in declaration " ++ show ident) Nothing
   caseDecl <- makeCaseDeclaration ident tuples
   return [caseDecl]
 toDecls (PositionedDeclaration pos d : ds) = do
diff --git a/src/Language/PureScript/TypeChecker.hs b/src/Language/PureScript/TypeChecker.hs
index 5aacf86..6a8f59b 100644
--- a/src/Language/PureScript/TypeChecker.hs
+++ b/src/Language/PureScript/TypeChecker.hs
@@ -26,8 +26,11 @@ import Language.PureScript.TypeChecker.Types as T
 import Language.PureScript.TypeChecker.Synonyms as T
 
 import Data.Maybe
+import Data.List (nub, (\\))
 import Data.Monoid ((<>))
+import Data.Foldable (for_)
 import qualified Data.Map as M
+
 import Control.Monad.State
 import Control.Monad.Error
 
@@ -87,6 +90,13 @@ addTypeClassDictionaries entries =
   let mentries = M.fromList [ ((canonicalizeDictionary entry, mn), entry) | entry@TypeClassDictionaryInScope{ tcdName = Qualified mn _ }  <- entries ]
   in modify $ \st -> st { checkEnv = (checkEnv st) { typeClassDictionaries = (typeClassDictionaries . checkEnv $ st) `M.union` mentries } }
 
+checkDuplicateTypeArguments :: [String] -> Check ()
+checkDuplicateTypeArguments args = for_ firstDup $ \dup ->
+  throwError . strMsg $ "Duplicate type argument '" ++ dup ++ "'"
+  where
+  firstDup :: Maybe String
+  firstDup = listToMaybe $ args \\ nub args
+
 checkTypeClassInstance :: ModuleName -> Type -> Check ()
 checkTypeClassInstance _ (TypeVar _) = return ()
 checkTypeClassInstance _ (TypeConstructor ctor) = do
@@ -114,6 +124,7 @@ typeCheckAll _ _ [] = return []
 typeCheckAll mainModuleName moduleName (d@(DataDeclaration dtype name args dctors) : rest) = do
   rethrow (strMsg ("Error in type constructor " ++ show name) <>) $ do
     when (dtype == Newtype) $ checkNewtype dctors
+    checkDuplicateTypeArguments args
     ctorKind <- kindsOf True moduleName name args (concatMap snd dctors)
     addDataType moduleName dtype name args dctors ctorKind
   ds <- typeCheckAll mainModuleName moduleName rest
@@ -128,9 +139,11 @@ typeCheckAll mainModuleName moduleName (d@(DataBindingGroupDeclaration tys) : re
     let syns = mapMaybe toTypeSynonym tys
     let dataDecls = mapMaybe toDataDecl tys
     (syn_ks, data_ks) <- kindsOfAll moduleName syns (map (\(_, name, args, dctors) -> (name, args, concatMap snd dctors)) dataDecls)
-    forM_ (zip dataDecls data_ks) $ \((dtype, name, args, dctors), ctorKind) ->
+    forM_ (zip dataDecls data_ks) $ \((dtype, name, args, dctors), ctorKind) -> do
+      checkDuplicateTypeArguments args
       addDataType moduleName dtype name args dctors ctorKind
-    forM_ (zip syns syn_ks) $ \((name, args, ty), kind) ->
+    forM_ (zip syns syn_ks) $ \((name, args, ty), kind) -> do
+      checkDuplicateTypeArguments args
       addTypeSynonym moduleName name args ty kind
   ds <- typeCheckAll mainModuleName moduleName rest
   return $ d : ds
@@ -143,6 +156,7 @@ typeCheckAll mainModuleName moduleName (d@(DataBindingGroupDeclaration tys) : re
   toDataDecl _ = Nothing
 typeCheckAll mainModuleName moduleName (d@(TypeSynonymDeclaration name args ty) : rest) = do
   rethrow (strMsg ("Error in type synonym " ++ show name) <>) $ do
+    checkDuplicateTypeArguments args
     kind <- kindsOf False moduleName name args [ty]
     addTypeSynonym moduleName name args ty kind
   ds <- typeCheckAll mainModuleName moduleName rest
@@ -213,3 +227,4 @@ typeCheckAll mainModuleName moduleName (PositionedDeclaration pos d : rest) =
   rethrowWithPosition pos $ do
     (d' : rest') <- typeCheckAll mainModuleName moduleName (d : rest)
     return (PositionedDeclaration pos d' : rest')
+
diff --git a/src/Language/PureScript/TypeChecker/Kinds.hs b/src/Language/PureScript/TypeChecker/Kinds.hs
index f44c1b4..26551a9 100644
--- a/src/Language/PureScript/TypeChecker/Kinds.hs
+++ b/src/Language/PureScript/TypeChecker/Kinds.hs
@@ -73,7 +73,7 @@ instance Unifiable Check Kind where
 kindOf :: ModuleName -> Type -> Check Kind
 kindOf _ ty =
   rethrow (mkErrorStack "Error checking kind" (Just (TypeError ty)) <>) $
-    fmap tidyUp . liftUnify $ starIfUnknown <$> infer ty
+    fmap (starIfUnknown . tidyUp) . liftUnify $ infer ty
   where
   tidyUp (k, sub) = sub $? k
 
diff --git a/src/Language/PureScript/TypeChecker/Types.hs b/src/Language/PureScript/TypeChecker/Types.hs
index bfbe16a..0c1e72b 100644
--- a/src/Language/PureScript/TypeChecker/Types.hs
+++ b/src/Language/PureScript/TypeChecker/Types.hs
@@ -357,12 +357,12 @@ entails env moduleName context = solve (sortedNubBy canonicalizeDictionary (filt
 	  -- Turn a DictionaryValue into a Expr
 	  dictionaryValueToValue :: DictionaryValue -> Expr
 	  dictionaryValueToValue (LocalDictionaryValue fnName) = Var fnName
-	  dictionaryValueToValue (GlobalDictionaryValue fnName) = App (Var fnName) (ObjectLiteral [])
+	  dictionaryValueToValue (GlobalDictionaryValue fnName) = App (Var fnName) valUndefined
 	  dictionaryValueToValue (DependentDictionaryValue fnName dicts) = foldl App (Var fnName) (map dictionaryValueToValue dicts)
 	  dictionaryValueToValue (SubclassDictionaryValue dict superclassName index) =
 	    App (Accessor (C.__superclass_ ++ show superclassName ++ "_" ++ show index)
 	                  (dictionaryValueToValue dict))
-	        (ObjectLiteral [])
+	        valUndefined
 	  -- Ensure that a substitution is valid
 	  verifySubstitution :: [(String, Type)] -> Maybe [(String, Type)]
 	  verifySubstitution subst = do
@@ -393,6 +393,9 @@ entails env moduleName context = solve (sortedNubBy canonicalizeDictionary (filt
 	  dictTrace (SubclassDictionaryValue dict _ _) = dictTrace dict
 	  dictTrace other = other
 
+    valUndefined :: Expr
+    valUndefined = Var (Qualified (Just (ModuleName [ProperName C.prim])) (Ident C.undefined))
+
 -- |
 -- Check all values in a list pairwise match a predicate
 --
diff --git a/tests/Main.hs b/tests/Main.hs
index 4d8e306..debd733 100644
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -27,12 +27,8 @@ import System.Process
 import System.FilePath (pathSeparator)
 import System.Directory (getCurrentDirectory, getTemporaryDirectory, getDirectoryContents, findExecutable)
 import Text.Parsec (ParseError)
-import qualified Paths_purescript as Paths
 import qualified System.IO.UTF8 as U
 
-preludeFilename :: IO FilePath
-preludeFilename = Paths.getDataFileName "prelude/prelude.purs"
-
 readInput :: [FilePath] -> IO (Either ParseError [P.Module])
 readInput inputFiles = fmap (fmap concat . sequence) $ forM inputFiles $ \inputFile -> do
   text <- U.readFile inputFile
@@ -44,7 +40,7 @@ compile opts inputFiles = do
   case modules of
     Left parseError ->
       return (Left $ show parseError)
-    Right ms -> return $ P.compile opts ms
+    Right ms -> return $ P.compile opts ms [] 
 
 assert :: FilePath -> P.Options -> FilePath -> (Either String (String, String, P.Environment) -> IO (Maybe String)) -> IO ()
 assert preludeExterns opts inputFile f = do
@@ -80,7 +76,7 @@ findNodeProcess = runMaybeT . msum $ map (MaybeT . findExecutable) names
 
 main :: IO ()
 main = do
-  prelude <- preludeFilename
+  prelude <- P.preludeFilename
   putStrLn "Compiling Prelude"
   preludeResult <- compile (P.defaultOptions { P.optionsBrowserNamespace = Just "Tests" }) [prelude]
   case preludeResult of