foldl1' was added to Data.List in GHC 6.4.x

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

diff --git a/compiler/utils/Util.lhs b/compiler/utils/Util.lhs
index 2d5e740..6cefad6 100644 (file)
--- a/compiler/utils/Util.lhs
+++ b/compiler/utils/Util.lhs
@@ -20,6 +20,7 @@ module Util (
        mapFst, mapSnd,
        mapAndUnzip, mapAndUnzip3,
        nOfThem, filterOut, partitionWith, splitEithers,
+        foldl1',
 
        lengthExceeds, lengthIs, lengthAtLeast, 
        listLengthCmp, atLength, equalLength, compareLength,
@@ -88,8 +89,8 @@ module Util (
 
 import FastTypes
 
-#ifdef DEBUG
-import Panic           ( panic, trace )
+#if defined(DEBUG) || __GLASGOW_HASKELL__ < 604
+import Panic
 #endif
 
 import Control.Exception ( Exception(..), finally, catchDyn, throw )
@@ -98,11 +99,10 @@ import Data.Dynamic ( Typeable )
 import Data.IORef      ( IORef, newIORef )
 import System.IO.Unsafe        ( unsafePerformIO )
 import Data.IORef      ( readIORef, writeIORef )
+import Data.List        hiding (group)
 
 import qualified Data.List as List ( elem )
-#ifndef DEBUG
-import Data.List               ( zipWith4 )
-#else
+#ifdef DEBUG
 import qualified Data.List as List ( notElem )
 #endif
 
@@ -363,6 +363,16 @@ isn'tIn msg x ys
 # endif /* DEBUG */
 \end{code}
 
+foldl1' was added in GHC 6.4
+
+\begin{code}
+#if __GLASGOW_HASKELL__ < 604
+foldl1'                  :: (a -> a -> a) -> [a] -> a
+foldl1' f (x:xs)         =  foldl' f x xs
+foldl1' _ []             =  panic "foldl1'"
+#endif
+\end{code}
+
 %************************************************************************
 %*                                                                     *
 \subsubsection[Utils-Carsten-mergesort]{A mergesort from Carsten}