Add a type signature

[ghc-hetmet.git] / compiler / utils / Util.lhs

diff --git a/compiler/utils/Util.lhs b/compiler/utils/Util.lhs
index 522f795..0a77e4d 100644 (file)
--- a/compiler/utils/Util.lhs
+++ b/compiler/utils/Util.lhs
@@ -1,4 +1,5 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The University of Glasgow 1992-2002
 %
 \section[Util]{Highly random utility functions}
@@ -11,7 +12,7 @@ module Util (
         zipLazy, stretchZipWith,
        mapFst, mapSnd,
        mapAndUnzip, mapAndUnzip3,
-       nOfThem, filterOut,
+       nOfThem, filterOut, partitionWith, splitEithers,
 
        lengthExceeds, lengthIs, lengthAtLeast, 
        listLengthCmp, atLength, equalLength, compareLength,
@@ -38,7 +39,7 @@ module Util (
 
        -- comparisons
        isEqual, eqListBy, 
-       thenCmp, cmpList, prefixMatch, suffixMatch, maybePrefixMatch,
+       thenCmp, cmpList, maybePrefixMatch,
        removeSpaces,
 
        -- strictness
@@ -82,26 +83,26 @@ module Util (
 import Panic           ( panic, trace )
 import FastTypes
 
-import EXCEPTION       ( Exception(..), finally, throwDyn, catchDyn, throw )
-import qualified EXCEPTION as Exception
-import DYNAMIC         ( Typeable )
-import DATA_IOREF      ( IORef, newIORef )
-import UNSAFE_IO       ( unsafePerformIO )
-import DATA_IOREF      ( readIORef, writeIORef )
+import Control.Exception ( Exception(..), finally, catchDyn, throw )
+import qualified Control.Exception as Exception
+import Data.Dynamic    ( Typeable )
+import Data.IORef      ( IORef, newIORef )
+import System.IO.Unsafe        ( unsafePerformIO )
+import Data.IORef      ( readIORef, writeIORef )
 
-import qualified List  ( elem, notElem )
+import qualified Data.List as List ( elem, notElem )
 
 #ifndef DEBUG
-import List            ( zipWith4 )
+import Data.List               ( zipWith4 )
 #endif
 
-import Monad           ( when )
-import IO              ( catch, isDoesNotExistError )
-import Directory       ( doesDirectoryExist, createDirectory )
-import Char            ( isUpper, isAlphaNum, isSpace, ord, isDigit )
-import Ratio           ( (%) )
-import Time            ( ClockTime )
-import Directory       ( getModificationTime )
+import Control.Monad   ( when )
+import SYSTEM_IO_ERROR as IO ( catch, isDoesNotExistError )
+import System.Directory        ( doesDirectoryExist, createDirectory,
+                          getModificationTime )
+import Data.Char       ( isUpper, isAlphaNum, isSpace, ord, isDigit )
+import Data.Ratio      ( (%) )
+import System.Time     ( ClockTime )
 
 infixr 9 `thenCmp`
 \end{code}
@@ -167,6 +168,22 @@ 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
@@ -671,12 +688,6 @@ 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
-
 maybePrefixMatch :: String -> String -> Maybe String
 maybePrefixMatch []    rest = Just rest
 maybePrefixMatch (_:_) []   = Nothing
@@ -684,9 +695,6 @@ 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}
@@ -697,31 +705,6 @@ 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
@@ -750,6 +733,7 @@ consIORef var x = do
 Module names:
 
 \begin{code}
+looksLikeModuleName :: String -> Bool
 looksLikeModuleName [] = False
 looksLikeModuleName (c:cs) = isUpper c && go cs
   where go [] = True
@@ -873,13 +857,9 @@ 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