[project @ 1999-01-23 17:46:01 by sof]

Move ST <--> IO coercion functions from IOExts to (Lazy)?ST

ghc/lib/exts/IOExts.lhs

@@ -48,8 +48,6 @@ module IOExts
 #endif
 	
 	, unsafePtrEq
-	, unsafeIOToST
-	, stToIO
 
         ) where
 
@@ -161,18 +159,6 @@ trace string expr = unsafePerformIO $ do
 #endif
 \end{code}
 
-\begin{code}
-unsafeIOToST	   :: IO a -> ST s a
-#ifdef __HUGS__
-unsafeIOToST = primUnsafeCoerce
-#else
-unsafeIOToST (IO io) = ST $ \ s ->
-    case ((unsafeCoerce# io) s) of
-      (#  new_s, a #) -> unsafeCoerce# (STret new_s a)
---      IOfail new_s e -> error ("I/O Error (unsafeIOToST): " ++ showsPrec 0 e "\n")
-#endif
-\end{code}
-
 Not something you want to call normally, but useful
 in the cases where you do want to flush stuff out of
 the heap or make sure you've got room enough

ghc/lib/exts/LazyST.lhs

@@ -26,6 +26,8 @@ module LazyST (
 	thawSTArray, freezeSTArray, unsafeFreezeSTArray, 
 	Ix,
 
+	ST.unsafeIOToST, ST.stToIO,
+
 	strictToLazyST, lazyToStrictST
     ) where
 
@@ -80,6 +82,7 @@ writeSTRef :: ST.STRef s a -> a -> ST s ()
 newSTRef   = strictToLazyST . ST.newSTRef
 readSTRef  = strictToLazyST . ST.readSTRef
 writeSTRef r a = strictToLazyST (ST.writeSTRef r a)
+
 \end{code}
 
 %*********************************************************

ghc/lib/exts/ST.lhs

@@ -21,6 +21,8 @@ module ST (
 	STRef,
 	newSTRef, readSTRef, writeSTRef,
 
+	unsafeIOToST, stToIO,
+
 	STArray,
 	newSTArray, readSTArray, writeSTArray, boundsSTArray, 
 	thawSTArray, freezeSTArray, unsafeFreezeSTArray, 
@@ -37,7 +39,8 @@ import PreludeBuiltin
 #else
 import PrelArr
 import PrelST
-import PrelBase	( Eq(..), Int, Bool, ($), ()(..) )
+import PrelBase	( Eq(..), Int, Bool, ($), ()(..), unsafeCoerce# )
+import PrelIOBase ( IO(..), stToIO )
 #endif
 import Monad
 import Ix
@@ -149,3 +152,15 @@ unsafeFreezeSTArray (STArray arr) = unsafeFreezeArray arr
 #endif
 \end{code}
 
+
+\begin{code}
+unsafeIOToST	   :: IO a -> ST s a
+#ifdef __HUGS__
+unsafeIOToST = primUnsafeCoerce
+#else
+unsafeIOToST (IO io) = ST $ \ s ->
+    case ((unsafeCoerce# io) s) of
+      (#  new_s, a #) -> unsafeCoerce# (STret new_s a)
+--      IOfail new_s e -> error ("I/O Error (unsafeIOToST): " ++ showsPrec 0 e "\n")
+#endif
+\end{code}