X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=GHC%2FArr.lhs;h=8f439cd85e97a232f578874083f29b996c5e134c;hb=7c0b04fd273621130062418bb764809c79488dd2;hp=c5e945ffdf636552f6e49900ad6bdbb72e8c499f;hpb=7953d86d3d7649f948be2757a15c99856322d296;p=haskell-directory.git

diff --git a/GHC/Arr.lhs b/GHC/Arr.lhs
index c5e945f..8f439cd 100644
--- a/GHC/Arr.lhs
+++ b/GHC/Arr.lhs
@@ -1,5 +1,5 @@
 \begin{code}
-{-# OPTIONS_GHC -fno-implicit-prelude #-}
+{-# OPTIONS_GHC -fno-implicit-prelude -fno-bang-patterns #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  GHC.Arr
@@ -75,12 +75,16 @@ class (Ord a) => Ix a where
     unsafeRangeSize     :: (a,a) -> Int
 
 	-- Must specify one of index, unsafeIndex
-    index b i | inRange b i = unsafeIndex b i
+    index b i | inRange b i = unsafeIndex b i	
 	      | otherwise   = error "Error in array index"
     unsafeIndex b i = index b i
 
     rangeSize b@(_l,h) | inRange b h = unsafeIndex b h + 1
-		       | otherwise   = 0
+		       | otherwise   = 0	-- This case is only here to
+						-- check for an empty range
+	-- NB: replacing (inRange b h) by (l <= h) fails for
+	--     tuples.  E.g.  (1,2) <= (2,1) but the range is empty
+
     unsafeRangeSize b@(_l,h) = unsafeIndex b h + 1
 \end{code}
 
@@ -195,15 +199,15 @@ instance Ix () where
 instance (Ix a, Ix b) => Ix (a, b) where -- as derived
     {-# SPECIALISE instance Ix (Int,Int) #-}
 
-    {- INLINE range #-}
+    {-# INLINE range #-}
     range ((l1,l2),(u1,u2)) =
       [ (i1,i2) | i1 <- range (l1,u1), i2 <- range (l2,u2) ]
 
-    {- INLINE unsafeIndex #-}
+    {-# INLINE unsafeIndex #-}
     unsafeIndex ((l1,l2),(u1,u2)) (i1,i2) =
       unsafeIndex (l1,u1) i1 * unsafeRangeSize (l2,u2) + unsafeIndex (l2,u2) i2
 
-    {- INLINE inRange #-}
+    {-# INLINE inRange #-}
     inRange ((l1,l2),(u1,u2)) (i1,i2) =
       inRange (l1,u1) i1 && inRange (l2,u2) i2