X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Futils%2FUtil.lhs;h=495df8257fe0af8d175c21687549f52e272d7e81;hp=3eff34b3d53824800da7fe69a8d9f9067944c511;hb=41b4b210247d5cf13952d4e115fc4d6b58eef234;hpb=046ee54f048ddd721dcee41916d6a6f68db3b15b

diff --git a/compiler/utils/Util.lhs b/compiler/utils/Util.lhs
index 3eff34b..495df82 100644
--- a/compiler/utils/Util.lhs
+++ b/compiler/utils/Util.lhs
@@ -12,7 +12,7 @@ module Util (
         zipLazy, stretchZipWith,
 	mapFst, mapSnd,
 	mapAndUnzip, mapAndUnzip3,
-	nOfThem, filterOut,
+	nOfThem, filterOut, partitionWith, splitEithers,
 
 	lengthExceeds, lengthIs, lengthAtLeast, 
 	listLengthCmp, atLength, equalLength, compareLength,
@@ -32,18 +32,17 @@ module Util (
 	transitiveClosure,
 
 	-- accumulating
-	mapAccumL, mapAccumR, mapAccumB, 
 	foldl2, count, all2,
 	
 	takeList, dropList, splitAtList, split,
 
 	-- comparisons
 	isEqual, eqListBy, 
-	thenCmp, cmpList, prefixMatch, suffixMatch, maybePrefixMatch,
+	thenCmp, cmpList, maybePrefixMatch,
 	removeSpaces,
 
 	-- strictness
-	foldl', seqList,
+	seqList,
 
 	-- pairs
 	unzipWith,
@@ -80,9 +79,12 @@ module Util (
 
 #include "HsVersions.h"
 
-import Panic		( panic, trace )
 import FastTypes
 
+#ifdef DEBUG
+import Panic		( panic, trace )
+#endif
+
 import Control.Exception ( Exception(..), finally, catchDyn, throw )
 import qualified Control.Exception as Exception
 import Data.Dynamic	( Typeable )
@@ -90,10 +92,11 @@ import Data.IORef	( IORef, newIORef )
 import System.IO.Unsafe	( unsafePerformIO )
 import Data.IORef	( readIORef, writeIORef )
 
-import qualified Data.List as List ( elem, notElem )
-
+import qualified Data.List as List ( elem )
 #ifndef DEBUG
 import Data.List		( zipWith4 )
+#else
+import qualified Data.List as List ( notElem )
 #endif
 
 import Control.Monad	( when )
@@ -109,41 +112,6 @@ infixr 9 `thenCmp`
 
 %************************************************************************
 %*									*
-\subsection{The Eager monad}
-%*									*
-%************************************************************************
-
-The @Eager@ monad is just an encoding of continuation-passing style,
-used to allow you to express "do this and then that", mainly to avoid
-space leaks. It's done with a type synonym to save bureaucracy.
-
-\begin{code}
-#if NOT_USED
-
-type Eager ans a = (a -> ans) -> ans
-
-runEager :: Eager a a -> a
-runEager m = m (\x -> x)
-
-appEager :: Eager ans a -> (a -> ans) -> ans
-appEager m cont = m cont
-
-thenEager :: Eager ans a -> (a -> Eager ans b) -> Eager ans b
-thenEager m k cont = m (\r -> k r cont)
-
-returnEager :: a -> Eager ans a
-returnEager v cont = cont v
-
-mapEager :: (a -> Eager ans b) -> [a] -> Eager ans [b]
-mapEager f [] = returnEager []
-mapEager f (x:xs) = f x			`thenEager` \ y ->
-		    mapEager f xs	`thenEager` \ ys ->
-		    returnEager (y:ys)
-#endif
-\end{code}
-
-%************************************************************************
-%*									*
 \subsection{A for loop}
 %*									*
 %************************************************************************
@@ -168,6 +136,22 @@ filterOut :: (a->Bool) -> [a] -> [a]
 filterOut p [] = []
 filterOut p (x:xs) | p x       = filterOut p xs
 		   | otherwise = x : filterOut p xs
+
+partitionWith :: (a -> Either b c) -> [a] -> ([b], [c])
+partitionWith f [] = ([],[])
+partitionWith f (x:xs) = case f x of
+			   Left  b -> (b:bs, cs)
+			   Right c -> (bs, c:cs)
+		       where
+			 (bs,cs) = partitionWith f xs
+
+splitEithers :: [Either a b] -> ([a], [b])
+splitEithers [] = ([],[])
+splitEithers (e : es) = case e of
+			  Left x -> (x:xs, ys)
+			  Right y -> (xs, y:ys)
+		      where
+			(xs,ys) = splitEithers es
 \end{code}
 
 A paranoid @zip@ (and some @zipWith@ friends) that checks the lists
@@ -507,72 +491,6 @@ transitiveClosure succ eq xs
 %*									*
 %************************************************************************
 
-@mapAccumL@ behaves like a combination
-of  @map@ and @foldl@;
-it applies a function to each element of a list, passing an accumulating
-parameter from left to right, and returning a final value of this
-accumulator together with the new list.
-
-\begin{code}
-mapAccumL :: (acc -> x -> (acc, y)) 	-- Function of elt of input list
-					-- and accumulator, returning new
-					-- accumulator and elt of result list
-	    -> acc 		-- Initial accumulator
-	    -> [x] 		-- Input list
-	    -> (acc, [y])		-- Final accumulator and result list
-
-mapAccumL f b []     = (b, [])
-mapAccumL f b (x:xs) = (b'', x':xs') where
-					  (b', x') = f b x
-					  (b'', xs') = mapAccumL f b' xs
-\end{code}
-
-@mapAccumR@ does the same, but working from right to left instead.  Its type is
-the same as @mapAccumL@, though.
-
-\begin{code}
-mapAccumR :: (acc -> x -> (acc, y)) 	-- Function of elt of input list
-					-- and accumulator, returning new
-					-- accumulator and elt of result list
-	    -> acc 		-- Initial accumulator
-	    -> [x] 		-- Input list
-	    -> (acc, [y])		-- Final accumulator and result list
-
-mapAccumR f b []     = (b, [])
-mapAccumR f b (x:xs) = (b'', x':xs') where
-					  (b'', x') = f b' x
-					  (b', xs') = mapAccumR f b xs
-\end{code}
-
-Here is the bi-directional version, that works from both left and right.
-
-\begin{code}
-mapAccumB :: (accl -> accr -> x -> (accl, accr,y))
-      				-- Function of elt of input list
-      				-- and accumulator, returning new
-      				-- accumulator and elt of result list
-	  -> accl 			-- Initial accumulator from left
-	  -> accr 			-- Initial accumulator from right
-	  -> [x] 			-- Input list
-	  -> (accl, accr, [y])	-- Final accumulators and result list
-
-mapAccumB f a b []     = (a,b,[])
-mapAccumB f a b (x:xs) = (a'',b'',y:ys)
-   where
-	(a',b'',y)  = f a b' x
-	(a'',b',ys) = mapAccumB f a' b xs
-\end{code}
-
-A strict version of foldl.
-
-\begin{code}
-foldl'        :: (a -> b -> a) -> a -> [b] -> a
-foldl' f z xs = lgo z xs
-	     where
-		lgo z []     =  z
-		lgo z (x:xs) = (lgo $! (f z x)) xs
-\end{code}
-
 A combination of foldl with zip.  It works with equal length lists.
 
 \begin{code}
@@ -672,12 +590,8 @@ cmpList cmp (a:as) (b:bs)
 \end{code}
 
 \begin{code}
-prefixMatch :: Eq a => [a] -> [a] -> Bool
-prefixMatch [] _str = True
-prefixMatch _pat [] = False
-prefixMatch (p:ps) (s:ss) | p == s    = prefixMatch ps ss
-			  | otherwise = False
-
+-- This (with a more general type) is Data.List.stripPrefix from GHC 6.8.
+-- This definition can be removed once we require at least 6.8 to build.
 maybePrefixMatch :: String -> String -> Maybe String
 maybePrefixMatch []    rest = Just rest
 maybePrefixMatch (_:_) []   = Nothing
@@ -685,9 +599,6 @@ maybePrefixMatch (p:pat) (r:rest)
   | p == r    = maybePrefixMatch pat rest
   | otherwise = Nothing
 
-suffixMatch :: Eq a => [a] -> [a] -> Bool
-suffixMatch pat str = prefixMatch (reverse pat) (reverse str)
-
 removeSpaces :: String -> String
 removeSpaces = reverse . dropWhile isSpace . reverse . dropWhile isSpace
 \end{code}
@@ -698,31 +609,6 @@ removeSpaces = reverse . dropWhile isSpace . reverse . dropWhile isSpace
 %*									*
 %************************************************************************
 
-The following are curried versions of @fst@ and @snd@.
-
-\begin{code}
-#if NOT_USED
-cfst :: a -> b -> a	-- stranal-sem only (Note)
-cfst x y = x
-#endif
-\end{code}
-
-The following provide us higher order functions that, when applied
-to a function, operate on pairs.
-
-\begin{code}
-#if NOT_USED
-applyToPair :: ((a -> c),(b -> d)) -> (a,b) -> (c,d)
-applyToPair (f,g) (x,y) = (f x, g y)
-
-applyToFst :: (a -> c) -> (a,b)-> (c,b)
-applyToFst f (x,y) = (f x,y)
-
-applyToSnd :: (b -> d) -> (a,b) -> (a,d)
-applyToSnd f (x,y) = (x,f y)
-#endif
-\end{code}
-
 \begin{code}
 unzipWith :: (a -> b -> c) -> [(a, b)] -> [c]
 unzipWith f pairs = map ( \ (a, b) -> f a b ) pairs
@@ -751,6 +637,7 @@ consIORef var x = do
 Module names:
 
 \begin{code}
+looksLikeModuleName :: String -> Bool
 looksLikeModuleName [] = False
 looksLikeModuleName (c:cs) = isUpper c && go cs
   where go [] = True
@@ -874,13 +761,9 @@ handleDyn :: Typeable ex => (ex -> IO a) -> IO a -> IO a
 handleDyn = flip catchDyn
 
 handle :: (Exception -> IO a) -> IO a -> IO a
-#if __GLASGOW_HASKELL__ < 501
-handle = flip Exception.catchAllIO
-#else
 handle h f = f `Exception.catch` \e -> case e of
     ExitException _ -> throw e
     _               -> h e
-#endif
 
 -- --------------------------------------------------------------
 -- check existence & modification time at the same time