Fix warnings

3 files changed, 18 insertions, 15 deletions

diff --git a/libraries/base/Text/ParserCombinators/ReadP.hs b/libraries/base/Text/ParserCombinators/ReadP.hs
index 187a79602e..d286c5172b 100644
--- a/libraries/base/Text/ParserCombinators/ReadP.hs
+++ b/libraries/base/Text/ParserCombinators/ReadP.hs
@@ -114,7 +114,7 @@ instance Monad P where
 
   (Get f)      >>= k = Get (\c -> f c >>= k)
   (Look f)     >>= k = Look (\s -> f s >>= k)
-  Fail         >>= k = Fail
+  Fail         >>= _ = Fail
   (Result x p) >>= k = k x `mplus` (p >>= k)
   (Final r)    >>= k = final [ys' | (x,s) <- r, ys' <- run (k x) s]
 
@@ -218,9 +218,9 @@ R f1 +++ R f2 = R (\k -> f1 k `mplus` f2 k)
 --   locally produces any result at all, then right parser is
 --   not used.
 #ifdef __GLASGOW_HASKELL__
-R f <++ q =
+R f0 <++ q =
   do s <- look
-     probe (f return) s 0#
+     probe (f0 return) s 0#
  where
   probe (Get f)        (c:s) n = probe (f c) s (n+#1#)
   probe (Look f)       s     n = probe (f s) s n
@@ -258,10 +258,10 @@ gather (R m) =
   R (\k -> gath id (m (\a -> return (\s -> k (s,a)))))  
  where
   gath l (Get f)      = Get (\c -> gath (l.(c:)) (f c))
-  gath l Fail         = Fail
+  gath _ Fail         = Fail
   gath l (Look f)     = Look (\s -> gath l (f s))
   gath l (Result k p) = k (l []) `mplus` gath l p
-  gath l (Final r)    = error "do not use readS_to_P in gather!"
+  gath _ (Final _)    = error "do not use readS_to_P in gather!"
 
 -- ---------------------------------------------------------------------------
 -- Derived operations
diff --git a/libraries/base/Text/ParserCombinators/ReadPrec.hs b/libraries/base/Text/ParserCombinators/ReadPrec.hs
index 88b5678be2..361f11af86 100644
--- a/libraries/base/Text/ParserCombinators/ReadPrec.hs
+++ b/libraries/base/Text/ParserCombinators/ReadPrec.hs
@@ -68,7 +68,7 @@ import GHC.Base
 -- ---------------------------------------------------------------------------
 -- The readPrec type
 
-newtype ReadPrec a = P { unP :: Prec -> ReadP a }
+newtype ReadPrec a = P (Prec -> ReadP a)
 
 -- Functor, Monad, MonadPlus
 
@@ -104,7 +104,7 @@ step (P f) = P (\n -> f (n+1))
 
 reset :: ReadPrec a -> ReadPrec a
 -- ^ Resets the precedence context to zero.
-reset (P f) = P (\n -> f minPrec)
+reset (P f) = P (\_ -> f minPrec)
 
 prec :: Prec -> ReadPrec a -> ReadPrec a
 -- ^ @(prec n p)@ checks whether the precedence context is 
diff --git a/libraries/base/Text/Read/Lex.hs b/libraries/base/Text/Read/Lex.hs
index a2acf471a3..94292e0a2c 100644
--- a/libraries/base/Text/Read/Lex.hs
+++ b/libraries/base/Text/Read/Lex.hs
@@ -162,10 +162,10 @@ lexChar = do { (c,_) <- lexCharE; return c }
 
 lexCharE :: ReadP (Char, Bool)  -- "escaped or not"?
 lexCharE =
-  do c <- get
-     if c == '\\'
-       then do c <- lexEsc; return (c, True)
-       else do return (c, False)
+  do c1 <- get
+     if c1 == '\\'
+       then do c2 <- lexEsc; return (c2, True)
+       else do return (c1, False)
  where 
   lexEsc =
     lexEscChar
@@ -360,8 +360,8 @@ lexFrac :: ReadP (Maybe Digits)
 -- Read the fractional part; fail if it doesn't
 -- start ".d" where d is a digit
 lexFrac = do char '.'
-             frac <- lexDigits 10
-             return (Just frac)
+             fraction <- lexDigits 10
+             return (Just fraction)
 
 lexExp :: ReadP (Maybe Integer)
 lexExp = do char 'e' +++ char 'E'
@@ -393,13 +393,13 @@ lexInteger base =
 
 val :: Num a => a -> a -> Digits -> a
 -- val base y [d1,..,dn] = y ++ [d1,..,dn], as it were
-val base y []     = y
+val _    y []     = y
 val base y (x:xs) = y' `seq` val base y' xs
  where
   y' = y * base + fromIntegral x
 
 frac :: Integral a => a -> a -> a -> Digits -> Ratio a
-frac base a b []     = a % b
+frac _    a b []     = a % b
 frac base a b (x:xs) = a' `seq` b' `seq` frac base a' b' xs
  where
   a' = a * base + fromIntegral x
@@ -418,6 +418,9 @@ valDig 16 c
   | 'A' <= c && c <= 'F' = Just (ord c - ord 'A' + 10)
   | otherwise            = Nothing
 
+valDig _ _ = error "valDig: Bad base"
+
+valDecDig :: Char -> Maybe Int
 valDecDig c
   | '0' <= c && c <= '9' = Just (ord c - ord '0')
   | otherwise            = Nothing