Remove redundant "do", "return" and language extensions from base

15 files changed, 25 insertions, 27 deletions

diff --git a/libraries/base/tests/Concurrent/MVar001.hs b/libraries/base/tests/Concurrent/MVar001.hs
index 6062cbfa46..0d96a7eb27 100644
--- a/libraries/base/tests/Concurrent/MVar001.hs
+++ b/libraries/base/tests/Concurrent/MVar001.hs
@@ -78,7 +78,7 @@ perform' mv (a:as) =
 
 
 actions :: Gen [Action]
-actions = do
+actions =
   oneof [liftM (NewEmptyMVar:) (actions' True),
          liftM2 (:) (liftM NewMVar arbitrary) (actions' False)]
 
diff --git a/libraries/base/tests/IO/encoding001.hs b/libraries/base/tests/IO/encoding001.hs
index c92f8a3ef5..df3c5f914c 100644
--- a/libraries/base/tests/IO/encoding001.hs
+++ b/libraries/base/tests/IO/encoding001.hs
@@ -33,7 +33,7 @@ main = do
   hClose h
 
   -- convert the UTF-32BE file into each other encoding
-  forM_ encodings $ \(enc,name) -> do
+  forM_ encodings $ \(enc,name) ->
      when (name /=  "utf32be") $ do
        hin <- openFile (file <.> "utf32be") ReadMode
        hSetEncoding hin utf32be
diff --git a/libraries/base/tests/IO/encoding004.hs b/libraries/base/tests/IO/encoding004.hs
index 62ef5d6a93..ffd76191f3 100644
--- a/libraries/base/tests/IO/encoding004.hs
+++ b/libraries/base/tests/IO/encoding004.hs
@@ -58,8 +58,8 @@ main = forM_ [ ("CP936",  2, "CP936",      Just "CP936-UTF8")  -- Representative
         utf8_bs <- BS.readFile ("encoded-data" </> utf8_file <.> "txt")
         Right expected <- decode utf8 utf8_bs
         Right actual   <- decode enc  bs
-        unless (expected == actual) $ do
-            putStrLn (bsDiff 0 actual expected)
+        unless (expected == actual) $
+          putStrLn (bsDiff 0 actual expected)
 
 forTruncations :: BS.ByteString -> (BS.ByteString -> IO a) -> IO [a]
 forTruncations bs f = forSplits bs $ \before _ -> f before
diff --git a/libraries/base/tests/IO/hClose002.hs b/libraries/base/tests/IO/hClose002.hs
index ebf26b4663..20eb0f888a 100644
--- a/libraries/base/tests/IO/hClose002.hs
+++ b/libraries/base/tests/IO/hClose002.hs
@@ -27,6 +27,6 @@ showPossibleException f = do e <- try f
                              print (e :: Either SomeException ())
 
 naughtyClose h = 
-  withHandle_ "naughtyClose" h $ \ Handle__{haDevice=dev} -> do
+  withHandle_ "naughtyClose" h $ \ Handle__{haDevice=dev} ->
      IODevice.close dev
 
diff --git a/libraries/base/tests/IO/hClose003.hs b/libraries/base/tests/IO/hClose003.hs
index cbaf49d6db..6d962fd94e 100644
--- a/libraries/base/tests/IO/hClose003.hs
+++ b/libraries/base/tests/IO/hClose003.hs
@@ -38,5 +38,5 @@ showPossibleException f = do
   sanitise' (x:xs) = if isDigit x then (sanitise' xs) else (x:(sanitise xs))
 
 naughtyClose h = 
-  withHandle_ "naughtyClose" h $ \ Handle__{haDevice=dev} -> do
+  withHandle_ "naughtyClose" h $ \ Handle__{haDevice=dev} ->
      IODevice.close dev
diff --git a/libraries/base/tests/IO/hDuplicateTo001.hs b/libraries/base/tests/IO/hDuplicateTo001.hs
index 99f956a0df..e286235e14 100644
--- a/libraries/base/tests/IO/hDuplicateTo001.hs
+++ b/libraries/base/tests/IO/hDuplicateTo001.hs
@@ -18,7 +18,7 @@ main = do
    putStrLn "bla"
 
 
-getfd h@(FileHandle _ mvar) = do
+getfd h@(FileHandle _ mvar) =
   withMVar mvar $ \h__@Handle__{haDevice=dev} ->
    case cast dev of
      Just fd -> return (FD.fdFD fd)
diff --git a/libraries/base/tests/IO/hReady002.hs b/libraries/base/tests/IO/hReady002.hs
index b8b648065b..b13ef8911e 100644
--- a/libraries/base/tests/IO/hReady002.hs
+++ b/libraries/base/tests/IO/hReady002.hs
@@ -5,6 +5,6 @@ import System.Exit
 
 main = do
   m <- newEmptyMVar
-  forkIO $ do threadDelay 500000; putMVar m Nothing
-  forkIO $ do hReady stdin >>= putMVar m . Just
+  forkIO $ threadDelay 500000 >> putMVar m Nothing
+  forkIO $ hReady stdin >>= putMVar m . Just
   takeMVar m >>= print
diff --git a/libraries/base/tests/IO/newline001.hs b/libraries/base/tests/IO/newline001.hs
index 3da867509f..1c894422a9 100644
--- a/libraries/base/tests/IO/newline001.hs
+++ b/libraries/base/tests/IO/newline001.hs
@@ -101,7 +101,7 @@ testoutput b = do
   check "out2" b (toCRLF content) str
   hClose h
 
-check s b str1 str2 = do
+check s b str1 str2 =
   when (str1 /= str2) $ error ("failed: " ++ s ++ ", " ++ show b ++ '\n':show str1 ++ '\n':show str2)
 
 read_chars :: Handle -> IO String
diff --git a/libraries/base/tests/IO/readwrite002.hs b/libraries/base/tests/IO/readwrite002.hs
index 37c7da39cb..5795525b2c 100644
--- a/libraries/base/tests/IO/readwrite002.hs
+++ b/libraries/base/tests/IO/readwrite002.hs
@@ -29,7 +29,6 @@ main = do
    hSeek cd AbsoluteSeek 0
    hSetBuffering cd LineBuffering
    speak cd  `catchIOError` \ err -> if isEOFError err then putStrLn "\nCaught EOF" else ioError err
-   return ()
    hSeek cd AbsoluteSeek 0
    hSetBuffering cd (BlockBuffering Nothing)
    speak cd  `catchIOError` \ err -> if isEOFError err then putStrLn "\nCaught EOF" else ioError err
diff --git a/libraries/base/tests/T13167.hs b/libraries/base/tests/T13167.hs
index e41104cde9..d8808667b1 100644
--- a/libraries/base/tests/T13167.hs
+++ b/libraries/base/tests/T13167.hs
@@ -25,5 +25,5 @@ run = do
 quit :: MVar () -> IO ()
 quit m = do
   ref <- newIORef ()
-  void $ mkWeakIORef ref $ do
+  void $ mkWeakIORef ref $
     putMVar m ()
diff --git a/libraries/base/tests/T13896.hs b/libraries/base/tests/T13896.hs
index 9e269a4a7c..8b4c47f44a 100644
--- a/libraries/base/tests/T13896.hs
+++ b/libraries/base/tests/T13896.hs
@@ -65,11 +65,11 @@ main = do
   -- without escaping everything inside
 
   (filter (not . null) $
-   unescapeArgs "this\\ is\\ 'not escape\\d \"inside\"'\\ yo\n")
-   `assertEqual`
-   ["this is not escaped \"inside\" yo"]
+    unescapeArgs "this\\ is\\ 'not escape\\d \"inside\"'\\ yo\n")
+    `assertEqual`
+    ["this is not escaped \"inside\" yo"]
 
   (filter (not . null) $
-   unescapeArgs "this\\ is\\ \"not escape\\d 'inside'\"\\ yo\n")
-   `assertEqual`
-   ["this is not escaped 'inside' yo"]
+    unescapeArgs "this\\ is\\ \"not escape\\d 'inside'\"\\ yo\n")
+    `assertEqual`
+    ["this is not escaped 'inside' yo"]
diff --git a/libraries/base/tests/T9532.hs b/libraries/base/tests/T9532.hs
index e99a42b572..b9f280fcf8 100644
--- a/libraries/base/tests/T9532.hs
+++ b/libraries/base/tests/T9532.hs
@@ -68,7 +68,7 @@ main = do
 
     -- Compare impl-under-test with reference-impl
     checkCLZ :: (Typeable a, Show a, Integral a, FiniteBits a) => a -> IO ()
-    checkCLZ v = unless (vri == viut) $ do
+    checkCLZ v = unless (vri == viut) $
         putStrLn $ concat [ "FAILED: clz (0x", showHex v " :: ", tyName
                           , ") ==> (RI=", show vri, " vs. IUT=", show viut, ")"
                           ]
@@ -79,7 +79,7 @@ main = do
 
     -- Compare impl-under-test with reference-impl
     checkCTZ :: (Typeable a, Show a, Integral a, FiniteBits a) => a -> IO ()
-    checkCTZ v = unless (vri == viut) $ do
+    checkCTZ v = unless (vri == viut) $
         putStrLn $ concat [ "FAILED: ctz (0x", showHex v " :: ", tyName
                           , ") ==> (RI=", show vri, " vs. IUT=", show viut, ")"
                           ]
diff --git a/libraries/base/tests/foldableArray.hs b/libraries/base/tests/foldableArray.hs
index 92217d73d2..5caf4eeb76 100644
--- a/libraries/base/tests/foldableArray.hs
+++ b/libraries/base/tests/foldableArray.hs
@@ -6,7 +6,6 @@ module Main where
 
 import Prelude hiding (foldr, foldl, foldl', foldr1, foldl1, length, null, sum,
                        product, all, any, and, or)
-import Data.Foldable
 import Control.Exception
 import Data.Array
 import Data.Foldable
diff --git a/libraries/base/tests/qsem001.hs b/libraries/base/tests/qsem001.hs
index 0088c6e989..4254c2b9fc 100644
--- a/libraries/base/tests/qsem001.hs
+++ b/libraries/base/tests/qsem001.hs
@@ -68,7 +68,7 @@ sem_fifo = do
 sem_kill :: Assertion
 sem_kill  = do
   q <- new 0
-  t <- forkIO $ do wait q
+  t <- forkIO $ wait q
   threadDelay 100000
   killThread t
   m <- newEmptyMVar
@@ -80,8 +80,8 @@ sem_kill  = do
 sem_bracket :: Assertion
 sem_bracket = do
   q <- new 1
-  ts <- forM [1..100000] $ \n -> do
-     forkIO $ do bracket_ (wait q) (signal q) (return ())
+  ts <- forM [1..100000] $ \n ->
+     forkIO $ bracket_ (wait q) (signal q) (return ())
   mapM_ killThread ts
   wait q
 
diff --git a/libraries/base/tests/qsemn001.hs b/libraries/base/tests/qsemn001.hs
index c61d2896c2..3f76f376aa 100644
--- a/libraries/base/tests/qsemn001.hs
+++ b/libraries/base/tests/qsemn001.hs
@@ -92,7 +92,7 @@ semn3 = do
 semn_kill :: Assertion
 semn_kill  = do
   q <- new 0
-  t <- forkIO $ do wait q 1
+  t <- forkIO $ wait q 1
   threadDelay 10000
   killThread t
   m <- newEmptyMVar
@@ -103,7 +103,7 @@ semn_kill  = do
 sem_bracket :: Assertion
 sem_bracket = do
   q <- new 1
-  ts <- forM [1..100000] $ \n -> do
-     forkIO $ do bracket_ (wait q 1) (signal q 1) (return ())
+  ts <- forM [1..100000] $ \n ->
+     forkIO $ bracket_ (wait q 1) (signal q 1) (return ())
   mapM_ killThread ts
   wait q 1