[project @ 2001-06-29 09:41:37 by simonmar]

merge fptools/hslibs/lang/ST.lhs rev. 1.4

diff --git a/Control/Monad/ST.hs b/Control/Monad/ST.hs
index 6cbae95..7817add 100644 (file)
--- a/Control/Monad/ST.hs
+++ b/Control/Monad/ST.hs
@@ -8,7 +8,7 @@
 -- Stability   :  experimental
 -- Portability :  non-portable
 --
--- $Id: ST.hs,v 1.1 2001/06/28 14:15:02 simonmar Exp $
+-- $Id: ST.hs,v 1.2 2001/06/29 09:41:37 simonmar Exp $
 --
 -- The State Transformer Monad, ST
 --
@@ -37,9 +37,7 @@ import GHC.Prim               ( unsafeCoerce#, RealWorld )
 import GHC.IOBase      ( IO(..), stToIO )
 
 unsafeIOToST        :: IO a -> ST s a
-unsafeIOToST (IO io) = ST $ \ s ->
-    case ((unsafeCoerce# io) s) of
-      (#  new_s, a #) -> unsafeCoerce# (STret new_s a)
+unsafeIOToST (IO io) = ST $ \ s -> (unsafeCoerce# io) s
 #endif
 
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