[project @ 1998-01-08 18:03:08 by simonm]

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

diff --git a/ghc/compiler/basicTypes/UniqSupply.lhs b/ghc/compiler/basicTypes/UniqSupply.lhs
index 425e045..23bd2c0 100644 (file)
--- a/ghc/compiler/basicTypes/UniqSupply.lhs
+++ b/ghc/compiler/basicTypes/UniqSupply.lhs
@@ -4,32 +4,30 @@
 \section[UniqSupply]{The @UniqueSupply@ data type and a (monadic) supply thereof}
 
 \begin{code}
-#include "HsVersions.h"
-
 module UniqSupply (
 
        UniqSupply,             -- Abstractly
 
        getUnique, getUniques,  -- basic ops
 
-       UniqSM(..),             -- type: unique supply monad
-       initUs, thenUs, returnUs,
-       mapUs, mapAndUnzipUs,
+       UniqSM,         -- type: unique supply monad
+       initUs, thenUs, returnUs, fixUs,
+       mapUs, mapAndUnzipUs, mapAndUnzip3Us,
+       thenMaybeUs, mapAccumLUs,
 
        mkSplitUniqSupply,
-       splitUniqSupply,
-
-       -- and the access functions for the `builtin' UniqueSupply
-       getBuiltinUniques, mkBuiltinUnique,
-       mkPseudoUnique1, mkPseudoUnique2, mkPseudoUnique3
+       splitUniqSupply
   ) where
 
-import Ubiq{-uitous-}
+#include "HsVersions.h"
 
 import Unique
 import Util
 
-import PreludeGlaST
+
+import GlaExts
+import IOBase  ( IO(..), IOResult(..) )
+import PrelBase ( Char(..) )
 
 w2i x = word2Int# x
 i2w x = int2Word# x
@@ -62,7 +60,7 @@ data UniqSupply
 \end{code}
 
 \begin{code}
-mkSplitUniqSupply :: Char -> PrimIO UniqSupply
+mkSplitUniqSupply :: Char -> IO UniqSupply
 
 splitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply)
 getUnique :: UniqSupply -> Unique
@@ -70,31 +68,23 @@ getUniques :: Int -> UniqSupply -> [Unique]
 \end{code}
 
 \begin{code}
-mkSplitUniqSupply (MkChar c#)
+mkSplitUniqSupply (C# c#)
   = let
        mask# = (i2w (ord# c#)) `shiftL#` (i2w_s 24#)
 
        -- here comes THE MAGIC:
 
+       -- This is one of the most hammered bits in the whole compiler
        mk_supply#
-         = unsafe_interleave (
-               mk_unique   `thenPrimIO` \ uniq ->
-               mk_supply#  `thenPrimIO` \ s1 ->
-               mk_supply#  `thenPrimIO` \ s2 ->
-               returnPrimIO (MkSplitUniqSupply uniq s1 s2)
+         = unsafeInterleaveIO (
+               mk_unique   >>= \ uniq ->
+               mk_supply#  >>= \ s1 ->
+               mk_supply#  >>= \ s2 ->
+               return (MkSplitUniqSupply uniq s1 s2)
            )
-         where
-           -- inlined copy of unsafeInterleavePrimIO;
-           -- this is the single-most-hammered bit of code
-           -- in the compiler....
-           unsafe_interleave m s
-             = let
-                   (r, new_s) = m s
-               in
-               (r, s)
-
-       mk_unique = _ccall_ genSymZh            `thenPrimIO` \ (W# u#) ->
-                   returnPrimIO (MkInt (w2i (mask# `or#` u#)))
+
+       mk_unique = _ccall_ genSymZh            >>= \ (W# u#) ->
+                   return (I# (w2i (mask# `or#` u#)))
     in
     mk_supply#
 
@@ -102,13 +92,13 @@ splitUniqSupply (MkSplitUniqSupply _ s1 s2) = (s1, s2)
 \end{code}
 
 \begin{code}
-getUnique (MkSplitUniqSupply (MkInt n) _ _) = mkUniqueGrimily n
+getUnique (MkSplitUniqSupply (I# n) _ _) = mkUniqueGrimily n
 
-getUniques i@(MkInt i#) supply = i# `get_from` supply
+getUniques (I# i) supply = i `get_from` supply
   where
     get_from 0# _ = []
-    get_from n# (MkSplitUniqSupply (MkInt u#) _ s2)
-      = mkUniqueGrimily u# : get_from (n# `minusInt#` 1#) s2
+    get_from n (MkSplitUniqSupply (I# u) _ s2)
+      = mkUniqueGrimily u : get_from (n -# 1#) s2
 \end{code}
 
 %************************************************************************
@@ -122,11 +112,9 @@ 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 #-}
@@ -135,6 +123,10 @@ 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
@@ -156,35 +148,35 @@ mapUs f (x:xs)
     returnUs (r:rs)
 
 mapAndUnzipUs  :: (a -> UniqSM (b,c))   -> [a] -> UniqSM ([b],[c])
+mapAndUnzip3Us :: (a -> UniqSM (b,c,d)) -> [a] -> UniqSM ([b],[c],[d])
 
 mapAndUnzipUs f [] = returnUs ([],[])
 mapAndUnzipUs f (x:xs)
   = f x                        `thenUs` \ (r1,  r2)  ->
     mapAndUnzipUs f xs `thenUs` \ (rs1, rs2) ->
     returnUs (r1:rs1, r2:rs2)
-\end{code}
 
-%************************************************************************
-%*                                                                     *
-\subsubsection[UniqueSupplies-compiler]{@UniqueSupplies@ specific to the compiler}
-%*                                                                     *
-%************************************************************************
-
-\begin{code}
-mkPseudoUnique1, mkPseudoUnique2, mkPseudoUnique3,
- mkBuiltinUnique :: Int -> Unique
-
-mkBuiltinUnique i = mkUnique 'B' i
-mkPseudoUnique1 i = mkUnique 'C' i -- used for getItsUnique on Regs
-mkPseudoUnique2 i = mkUnique 'D' i -- ditto
-mkPseudoUnique3 i = mkUnique 'E' i -- ditto
-
-getBuiltinUniques :: Int -> [Unique]
-getBuiltinUniques n = map (mkUnique 'B') [1 .. n]
-\end{code}
-
-The following runs a uniq monad expression, using builtin uniq values:
-\begin{code}
---runBuiltinUs :: UniqSM a -> a
---runBuiltinUs m = snd (initUs uniqSupply_B m)
+mapAndUnzip3Us f [] = returnUs ([],[],[])
+mapAndUnzip3Us f (x:xs)
+  = f x                        `thenUs` \ (r1,  r2,  r3)  ->
+    mapAndUnzip3Us f xs        `thenUs` \ (rs1, rs2, rs3) ->
+    returnUs (r1:rs1, r2:rs2, r3:rs3)
+
+thenMaybeUs :: UniqSM (Maybe a) -> (a -> UniqSM (Maybe b)) -> UniqSM (Maybe b)
+thenMaybeUs m k
+  = m  `thenUs` \ result ->
+    case result of
+      Nothing -> returnUs Nothing
+      Just x  -> k x
+
+mapAccumLUs :: (acc -> x -> UniqSM (acc, y))
+           -> acc
+           -> [x]
+           -> UniqSM (acc, [y])
+
+mapAccumLUs f b []     = returnUs (b, [])
+mapAccumLUs f b (x:xs)
+  = f b x                          `thenUs` \ (b__2, x__2) ->
+    mapAccumLUs f b__2 xs          `thenUs` \ (b__3, xs__2) ->
+    returnUs (b__3, x__2:xs__2)
 \end{code}