[project @ 1997-11-24 15:43:22 by simonm]

[ghc-hetmet.git] / ghc / lib / glaExts / ST.lhs

diff --git a/ghc/lib/glaExts/ST.lhs b/ghc/lib/glaExts/ST.lhs
index ed3474d..6c0efba 100644 (file)
--- a/ghc/lib/glaExts/ST.lhs
+++ b/ghc/lib/glaExts/ST.lhs
@@ -42,7 +42,8 @@ import Ix
 %*********************************************************
 
 \begin{code}
-newtype STRef s a = STRef (MutableVar s a) deriving Eq
+newtype STRef s a = STRef (MutableVar s a) 
+    deriving Eq
 
 newSTRef :: a -> ST s (STRef s a)
 newSTRef v = newVar v >>= \ var -> return (STRef var)
@@ -61,7 +62,8 @@ writeSTRef (STRef var) v = writeVar var v
 %*********************************************************
 
 \begin{code}
-type STArray s ix elt = MutableArray s ix elt
+newtype STArray s ix elt = STArray (MutableArray s ix elt)
+    deriving Eq
 
 newSTArray             :: Ix ix => (ix,ix) -> elt -> ST s (STArray s ix elt)
 writeSTArray           :: Ix ix => STArray s ix elt -> ix -> elt -> ST s () 
@@ -71,12 +73,20 @@ thawSTArray                 :: Ix ix => Array ix elt -> ST s (STArray s ix elt)
 freezeSTArray          :: Ix ix => STArray s ix elt -> ST s (Array ix elt)
 unsafeFreezeSTArray    :: Ix ix => STArray s ix elt -> ST s (Array ix elt)
 
-newSTArray             = newArray
-boundsSTArray          = boundsOfArray
-readSTArray            = readArray
-writeSTArray           = writeArray
-thawSTArray            = thawArray
-freezeSTArray          = freezeArray
-unsafeFreezeSTArray    = unsafeFreezeArray
+newSTArray ixs elt = 
+    newArray ixs elt >>= \arr -> 
+    return (STArray arr)
+
+boundsSTArray (STArray arr) = boundsOfArray arr
+
+readSTArray (STArray arr) ix = readArray arr ix
+
+writeSTArray (STArray arr) ix elt = writeArray arr ix elt
+
+thawSTArray arr = thawArray arr >>= \starr -> return (STArray starr)
+
+freezeSTArray (STArray arr) = freezeArray arr
+
+unsafeFreezeSTArray (STArray arr) = unsafeFreezeArray arr
 \end{code}
-       
+