[project @ 1997-06-05 09:32:15 by sof]

[ghc-hetmet.git] / ghc / compiler / basicTypes / UniqSupply.lhs

diff --git a/ghc/compiler/basicTypes/UniqSupply.lhs b/ghc/compiler/basicTypes/UniqSupply.lhs
index 3cb2ca7..98e2888 100644 (file)
--- a/ghc/compiler/basicTypes/UniqSupply.lhs
+++ b/ghc/compiler/basicTypes/UniqSupply.lhs
@@ -13,7 +13,7 @@ module UniqSupply (
        getUnique, getUniques,  -- basic ops
 
        SYN_IE(UniqSM),         -- type: unique supply monad
-       initUs, thenUs, returnUs,
+       initUs, thenUs, returnUs, fixUs,
        mapUs, mapAndUnzipUs, mapAndUnzip3Us,
        thenMaybeUs, mapAccumLUs,
 
@@ -26,11 +26,16 @@ IMP_Ubiq(){-uitous-}
 import Unique
 import Util
 
-import PreludeGlaST
 
-#if __GLASGOW_HASKELL__ >= 200
+#if __GLASGOW_HASKELL__ == 201
+import PreludeGlaST
 # define WHASH     GHCbase.W#
+#elif __GLASGOW_HASKELL__ >= 202
+import GlaExts
+import STBase
+# define WHASH      GlaExts.W#
 #else
+import PreludeGlaST
 # define WHASH     W#
 #endif
 
@@ -80,24 +85,26 @@ mkSplitUniqSupply (C# c#)
        -- here comes THE MAGIC:
 
        mk_supply#
-         = unsafeInterleavePrimIO {-unsafe_interleave-} (
+         = unsafe_interleave (
                mk_unique   `thenPrimIO` \ uniq ->
                mk_supply#  `thenPrimIO` \ s1 ->
                mk_supply#  `thenPrimIO` \ s2 ->
                returnPrimIO (MkSplitUniqSupply uniq s1 s2)
            )
          where
-{-
+--
            -- inlined copy of unsafeInterleavePrimIO;
            -- this is the single-most-hammered bit of code
            -- in the compiler....
            -- Too bad it's not 1.3-portable...
-           unsafe_interleave m s
-             = let
-                   (r, new_s) = m s
-               in
-               (r, s)
--}
+           unsafe_interleave m =
+              MkST ( \ s ->
+               let
+                   (MkST m') = m
+                   (r, new_s) = m' s
+               in
+               (r, s))
+--
 
        mk_unique = _ccall_ genSymZh            `thenPrimIO` \ (WHASH u#) ->
                    returnPrimIO (I# (w2i (mask# `or#` u#)))
@@ -120,7 +127,7 @@ getUniques (I# i) supply = i `get_from` supply
   where
     get_from 0# _ = []
     get_from n (MkSplitUniqSupply (I# u) _ s2)
-      = mkUniqueGrimily u : get_from (n `minusInt#` 1#) s2
+      = mkUniqueGrimily u : get_from (n -# 1#) s2
 \end{code}
 
 %************************************************************************
@@ -134,11 +141,9 @@ type UniqSM result = UniqSupply -> result
 
 -- the initUs function also returns the final UniqSupply
 
-initUs :: UniqSupply -> UniqSM a -> (UniqSupply, a)
+initUs :: UniqSupply -> UniqSM a -> a
 
-initUs init_us m
-  = case (splitUniqSupply init_us) of { (s1, s2) ->
-    (s2, m s1) }
+initUs init_us m = m init_us
 
 {-# INLINE thenUs #-}
 {-# INLINE returnUs #-}
@@ -147,6 +152,10 @@ initUs init_us m
 
 @thenUs@ is where we split the @UniqSupply@.
 \begin{code}
+fixUs :: (a -> UniqSM a) -> UniqSM a
+fixUs m us
+  = r  where  r = m r us
+
 thenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
 
 thenUs expr cont us