Fixing kernel death, closes #505

ihaskell.cabal

@@ -127,7 +127,7 @@ library
 executable ihaskell
   -- .hs or .lhs file containing the Main module.
   main-is:             Main.hs
-  hs-source-dirs: src
+  hs-source-dirs: main
   other-modules: 
                    IHaskellPrelude
   ghc-options: -threaded
@@ -135,43 +135,20 @@ executable ihaskell
   -- Other library packages from which modules are imported.
   default-language:    Haskell2010
   build-depends:       
-                       aeson                >=0.7 && < 0.9,
+                       ihaskell -any,
                        base                 >=4.6 && < 4.9,
-                       base64-bytestring    >=1.0,
-                       bytestring           >=0.10,
-                       cereal               >=0.3,
-                       cmdargs              >=0.10,
-                       containers           >=0.5,
-                       directory            -any,
-                       filepath             -any,
-                       ghc                  >=7.6 || < 7.11,
-                       ghc-parser           >=0.1.7,
-                       ghc-paths            ==0.1.*,
-                       haskeline            -any,
-                       here                 ==1.2.*,
-                       hlint                >=1.9 && <2.0,
-                       haskell-src-exts     ==1.16.*,
-                       http-client          == 0.4.*,
-                       http-client-tls      == 0.2.*,
-                       MissingH             >=1.2,
-                       mtl                  >=2.1,
-                       parsec               -any,
-                       process              >=1.1,
-                       random               >=1.0,
-                       shelly               >=1.5,
-                       split                >= 0.2,
-                       stm                  -any,
-                       strict               >=0.3,
-                       system-argv0         -any,
-                       system-filepath      -any,
                        text                 >=0.11,
                        transformers         -any,
+                       ghc                  >=7.6 || < 7.11,
+                       here                 ==1.2.*,
+                       aeson                >=0.7 && < 0.9,
+                       bytestring           >=0.10,
+                       containers           >=0.5,
+                       strict               >=0.3,
                        unix                 >= 2.6,
-                       unordered-containers -any,
-                       utf8-string          -any,
-                       uuid                 >=1.3,
-                       vector               -any,
+                       directory            -any,
                        ipython-kernel       >=0.6.1
+
   if flag(binPkgDb)
     build-depends:       bin-package-db
 

main/IHaskellPrelude.hs

@@ -0,0 +1,149 @@
+{-# LANGUAGE CPP #-}
+module IHaskellPrelude (
+  module IHaskellPrelude,
+  module X,
+
+  -- Select reexports
+  Data.Typeable.Typeable,
+  Data.Typeable.cast,
+
+#if MIN_VERSION_ghc(7,8,0)
+  Data.Typeable.Proxy,
+
+  GHC.Exts.IsString,
+  GHC.Exts.IsList,
+#endif
+
+  System.IO.hPutStrLn,
+  System.IO.hPutStr,
+  System.IO.hPutChar,
+  System.IO.hPrint,
+  System.IO.stdout,
+  System.IO.stderr,
+  System.IO.stdin,
+  System.IO.getChar,
+  System.IO.getLine,
+  System.IO.writeFile,
+  System.IO.Handle,
+
+  System.IO.Strict.readFile,
+  System.IO.Strict.getContents,
+  System.IO.Strict.hGetContents,
+
+  Control.Exception.catch,
+  Control.Exception.SomeException,
+
+  Control.Applicative.Applicative(..),
+  Control.Applicative.ZipList(..),
+  (Control.Applicative.<$>),
+
+  Control.Concurrent.MVar.MVar,
+  Control.Concurrent.MVar.newMVar,
+  Control.Concurrent.MVar.newEmptyMVar,
+  Control.Concurrent.MVar.isEmptyMVar,
+  Control.Concurrent.MVar.readMVar,
+  Control.Concurrent.MVar.takeMVar,
+  Control.Concurrent.MVar.putMVar,
+  Control.Concurrent.MVar.modifyMVar,
+  Control.Concurrent.MVar.modifyMVar_,
+
+  Data.IORef.IORef,
+  Data.IORef.readIORef,
+  Data.IORef.writeIORef,
+  Data.IORef.modifyIORef',
+  Data.IORef.newIORef,
+
+  
+
+  -- Miscellaneous names
+  Data.Map.Map,
+  GHC.IO.FilePath,
+  Data.Text.Text,
+  Data.ByteString.ByteString,
+  Text.Printf.printf,
+  Data.Function.on,
+  ) where
+
+import           Prelude
+
+import           Data.Monoid            as X
+import           Data.Tuple             as X
+import           Control.Monad          as X
+import           Data.Maybe             as X
+import           Data.Either            as X
+import           Control.Monad.IO.Class as X
+import           Data.Ord               as X
+import           GHC.Show               as X
+import           GHC.Enum               as X
+import           GHC.Num                as X
+import           GHC.Real               as X
+import           GHC.Err                as X hiding (absentErr)
+#if MIN_VERSION_ghc(7,10,0)
+import           GHC.Base               as X hiding (Any, mapM, foldr, sequence, many, (<|>))
+#else
+import           GHC.Base               as X hiding (Any)
+#endif
+import           Data.List              as X hiding (head, last, tail, init, transpose, subsequences, permutations,
+                                        foldl, foldl1, maximum, minimum, scanl, scanl1, scanr, scanr1,
+                                        span, break, mapAccumL, mapAccumR, dropWhileEnd, (!!),
+                                        elemIndices, elemIndex, findIndex, findIndices, zip5, zip6,
+                                        zip7, zipWith5, zipWith6, zipWith7, unzip5, unzip6, unzip6,
+                                        delete, union, lookup, intersect, insert, deleteBy,
+                                        deleteFirstBy, unionBy, intersectBy, group, groupBy, insertBy,
+                                        maximumBy, minimumBy, genericLength, genericDrop, genericTake,
+                                        genericSplitAt, genericIndex, genericReplicate, inits, tails)
+
+import qualified Control.Applicative
+import qualified Data.Typeable
+import qualified Data.IORef
+import qualified Data.Map
+import qualified Data.Text
+import qualified Data.Text.Lazy
+import qualified Data.ByteString
+import qualified Data.ByteString.Lazy
+import qualified Data.Function
+import qualified GHC.Exts
+import qualified System.IO
+import qualified System.IO.Strict
+import qualified GHC.IO
+import qualified Text.Printf
+import qualified Control.Exception
+import qualified Control.Concurrent.MVar
+
+import qualified Data.List
+import qualified Prelude as P
+
+type LByteString = Data.ByteString.Lazy.ByteString
+
+type LText = Data.Text.Lazy.Text
+
+(headMay, tailMay, lastMay, initMay, maximumMay, minimumMay) =
+  (wrapEmpty head, wrapEmpty tail, wrapEmpty last,
+   wrapEmpty init, wrapEmpty maximum, wrapEmpty minimum)
+  where
+    wrapEmpty :: ([a] -> b) -> [a] -> Maybe b
+    wrapEmpty _ [] = Nothing
+    wrapEmpty f xs = Just (f xs)
+
+maximumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a
+maximumByMay _ [] = Nothing
+maximumByMay f xs = Just (Data.List.maximumBy f xs)
+
+minimumByMay :: (a -> a -> Ordering) -> [a] -> Maybe a
+minimumByMay _ [] = Nothing
+minimumByMay f xs = Just (Data.List.minimumBy f xs)
+
+readMay :: Read a => String -> Maybe a
+readMay = fmap fst . headMay . reads
+
+putStrLn :: (MonadIO m) => String -> m ()
+putStrLn = liftIO . P.putStrLn
+
+putStr :: (MonadIO m) => String -> m ()
+putStr = liftIO . P.putStr
+
+putChar :: MonadIO m => Char -> m ()
+putChar = liftIO . P.putChar
+
+print :: (MonadIO m, Show a) => a -> m ()
+print = liftIO . P.print

src/IHaskell/Eval/Evaluate.hs

@@ -350,20 +350,24 @@ evaluate kernelState code output = do
               TypeRep fing2 tycon2 subs2 = actualTypeRep
           in error $ concat
                        [ "Expecting value of type "
-                       , show expectedTypeRep
+                       , showTypeRep expectedTypeRep
                        , " but got value of type "
-                       , show actualTypeRep
-                       , "\n. Fingerprint expected "
-                       , show fing1
-                       , " but gotten "
-                       , show fing2
-                       , " with expected tycon "
-                       , show (tyConPackage tycon1, tyConModule tycon1, tyConName tycon1, tyConHash tycon1)
-                       , " but gotten "
-                       , show (tyConPackage tycon2, tyConModule tycon2, tyConName tycon2, tyConHash tycon2)
+                       , showTypeRep actualTypeRep
                        ]
         Just result -> return result
 
+    showTypeRep :: TypeRep -> String
+    showTypeRep (TypeRep fingerprint tycon subs) =
+      concat ["TypeRep "
+             , show fingerprint
+             , " "
+             , show (tyConPackage tycon, tyConModule tycon, tyConName tycon, tyConHash tycon)
+             , " "
+             , "["
+             , intercalate ", " (map showTypeRep subs)
+             , "]" 
+             ]
+
 safely :: KernelState -> Interpreter EvalOut -> Interpreter EvalOut
 safely state = ghandle handler . ghandle sourceErrorHandler
   where

src/IHaskellPrelude.hs

@@ -77,6 +77,7 @@ import           GHC.Show               as X
 import           GHC.Enum               as X
 import           GHC.Num                as X
 import           GHC.Real               as X
+import           GHC.Err                as X hiding (absentErr)
 #if MIN_VERSION_ghc(7,10,0)
 import           GHC.Base               as X hiding (Any, mapM, foldr, sequence, many, (<|>))
 #else