Add tests from testsuite/tests/h98

[ghc-base.git] / Text / ParserCombinators / ReadP.hs

diff --git a/Text/ParserCombinators/ReadP.hs b/Text/ParserCombinators/ReadP.hs
index 9e6dcee..27bba54 100644 (file)
--- a/Text/ParserCombinators/ReadP.hs
+++ b/Text/ParserCombinators/ReadP.hs
@@ -1,4 +1,11 @@
-{-# OPTIONS_GHC -XNoImplicitPrelude #-}
+{-# LANGUAGE CPP, NoImplicitPrelude #-}
+#ifndef __NHC__
+{-# LANGUAGE Rank2Types #-}
+#endif
+#ifdef __GLASGOW_HASKELL__
+{-# LANGUAGE MagicHash #-}
+#endif
+
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Text.ParserCombinators.ReadP
@@ -255,9 +262,10 @@ gather :: ReadP a -> ReadP (String, a)
 --   in addition returns the exact characters read.
 --   IMPORTANT NOTE: 'gather' gives a runtime error if its first argument
 --   is built using any occurrences of readS_to_P. 
-gather (R m) =
-  R (\k -> gath id (m (\a -> return (\s -> k (s,a)))))  
+gather (R m)
+  = R (\k -> gath id (m (\a -> return (\s -> k (s,a)))))  
  where
+  gath :: (String -> String) -> P (String -> P b) -> P b
   gath l (Get f)      = Get (\c -> gath (l.(c:)) (f c))
   gath _ Fail         = Fail
   gath l (Look f)     = Look (\s -> gath l (f s))
@@ -287,7 +295,7 @@ string :: String -> ReadP String
 string this = do s <- look; scan this s
  where
   scan []     _               = do return this
-  scan (x:xs) (y:ys) | x == y = do get; scan xs ys
+  scan (x:xs) (y:ys) | x == y = do _ <- get; scan xs ys
   scan _      _               = do pfail
 
 munch :: (Char -> Bool) -> ReadP String
@@ -298,7 +306,7 @@ munch p =
   do s <- look
      scan s
  where
-  scan (c:cs) | p c = do get; s <- scan cs; return (c:s)
+  scan (c:cs) | p c = do _ <- get; s <- scan cs; return (c:s)
   scan _            = do return ""
 
 munch1 :: (Char -> Bool) -> ReadP String
@@ -307,7 +315,8 @@ munch1 :: (Char -> Bool) -> ReadP String
 --   Hence NOT the same as (many1 (satisfy p))
 munch1 p =
   do c <- get
-     if p c then do s <- munch p; return (c:s) else pfail
+     if p c then do s <- munch p; return (c:s)
+            else pfail
 
 choice :: [ReadP a] -> ReadP a
 -- ^ Combines all parsers in the specified list.
@@ -321,7 +330,7 @@ skipSpaces =
   do s <- look
      skip s
  where
-  skip (c:s) | isSpace c = do get; skip s
+  skip (c:s) | isSpace c = do _ <- get; skip s
   skip _                 = do return ()
 
 count :: Int -> ReadP a -> ReadP [a]
@@ -332,9 +341,9 @@ count n p = sequence (replicate n p)
 between :: ReadP open -> ReadP close -> ReadP a -> ReadP a
 -- ^ @between open close p@ parses @open@, followed by @p@ and finally
 --   @close@. Only the value of @p@ is returned.
-between open close p = do open
+between open close p = do _ <- open
                           x <- p
-                          close
+                          _ <- close
                           return x
 
 option :: a -> ReadP a -> ReadP a
@@ -375,12 +384,12 @@ sepBy1 p sep = liftM2 (:) p (many (sep >> p))
 endBy :: ReadP a -> ReadP sep -> ReadP [a]
 -- ^ @endBy p sep@ parses zero or more occurrences of @p@, separated and ended
 --   by @sep@.
-endBy p sep = many (do x <- p ; sep ; return x)
+endBy p sep = many (do x <- p ; _ <- sep ; return x)
 
 endBy1 :: ReadP a -> ReadP sep -> ReadP [a]
 -- ^ @endBy p sep@ parses one or more occurrences of @p@, separated and ended
 --   by @sep@.
-endBy1 p sep = many1 (do x <- p ; sep ; return x)
+endBy1 p sep = many1 (do x <- p ; _ <- sep ; return x)
 
 chainr :: ReadP a -> ReadP (a -> a -> a) -> a -> ReadP a
 -- ^ @chainr p op x@ parses zero or more occurrences of @p@, separated by @op@.