Module header tidyup, phase 1

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

diff --git a/compiler/basicTypes/UniqSupply.lhs b/compiler/basicTypes/UniqSupply.lhs
index 41ad5c0..7937043 100644 (file)
--- a/compiler/basicTypes/UniqSupply.lhs
+++ b/compiler/basicTypes/UniqSupply.lhs
@@ -1,7 +1,7 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-\section[UniqSupply]{The @UniqueSupply@ data type and a (monadic) supply thereof}
 
 \begin{code}
 module UniqSupply (
@@ -25,8 +25,8 @@ module UniqSupply (
 
 import Unique
 
-import GLAEXTS
-import UNSAFE_IO       ( unsafeInterleaveIO )
+import GHC.Exts
+import System.IO.Unsafe        ( unsafeInterleaveIO )
 
 w2i x = word2Int# x
 i2w x = int2Word# x
@@ -47,7 +47,7 @@ which will be distinct from the first and from all others.
 
 \begin{code}
 data UniqSupply
-  = MkSplitUniqSupply Int      -- make the Unique with this
+  = MkSplitUniqSupply Int#     -- make the Unique with this
                   UniqSupply UniqSupply
                                -- when split => these two supplies
 \end{code}
@@ -73,14 +73,11 @@ mkSplitUniqSupply (C# c#)
        -- This is one of the most hammered bits in the whole compiler
        mk_supply#
          = unsafeInterleaveIO (
-               mk_unique   >>= \ uniq ->
+               genSymZh    >>= \ (W# u#) ->
                mk_supply#  >>= \ s1 ->
                mk_supply#  >>= \ s2 ->
-               return (MkSplitUniqSupply uniq s1 s2)
+               return (MkSplitUniqSupply (w2i (mask# `or#` u#)) s1 s2)
            )
-
-       mk_unique = genSymZh            >>= \ (W# u#) ->
-                   return (I# (w2i (mask# `or#` u#)))
     in
     mk_supply#
 
@@ -90,8 +87,8 @@ splitUniqSupply (MkSplitUniqSupply _ s1 s2) = (s1, s2)
 \end{code}
 
 \begin{code}
-uniqFromSupply  (MkSplitUniqSupply n _ _)  = mkUniqueGrimily n
-uniqsFromSupply (MkSplitUniqSupply n _ s2) = mkUniqueGrimily n : uniqsFromSupply s2
+uniqFromSupply  (MkSplitUniqSupply n _ _)  = mkUniqueGrimily (I# n)
+uniqsFromSupply (MkSplitUniqSupply n _ s2) = mkUniqueGrimily (I# n) : uniqsFromSupply s2
 \end{code}
 
 %************************************************************************
@@ -101,14 +98,19 @@ uniqsFromSupply (MkSplitUniqSupply n _ s2) = mkUniqueGrimily n : uniqsFromSupply
 %************************************************************************
 
 \begin{code}
-type UniqSM result = UniqSupply -> (result, UniqSupply)
+newtype UniqSM result = USM { unUSM :: UniqSupply -> (result, UniqSupply) }
+
+instance Monad UniqSM where
+  return = returnUs
+  (>>=) = thenUs
+  (>>)  = thenUs_
 
 -- the initUs function also returns the final UniqSupply; initUs_ drops it
 initUs :: UniqSupply -> UniqSM a -> (a,UniqSupply)
-initUs init_us m = case m init_us of { (r,us) -> (r,us) }
+initUs init_us m = case unUSM m init_us of { (r,us) -> (r,us) }
 
 initUs_ :: UniqSupply -> UniqSM a -> a
-initUs_ init_us m = case m init_us of { (r,us) -> r }
+initUs_ init_us m = case unUSM m init_us of { (r,us) -> r }
 
 {-# INLINE thenUs #-}
 {-# INLINE lazyThenUs #-}
@@ -119,38 +121,38 @@ initUs_ init_us m = case m init_us of { (r,us) -> r }
 @thenUs@ is where we split the @UniqSupply@.
 \begin{code}
 fixUs :: (a -> UniqSM a) -> UniqSM a
-fixUs m us
-  = (r,us')  where  (r,us') = m r us
+fixUs m = USM (\us -> let (r,us') = unUSM (m r) us in (r,us'))
 
 thenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
-thenUs expr cont us
-  = case (expr us) of { (result, us') -> cont result us' }
+thenUs (USM expr) cont
+  = USM (\us -> case (expr us) of 
+                  (result, us') -> unUSM (cont result) us')
 
 lazyThenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
-lazyThenUs expr cont us
-  = let (result, us') = expr us in cont result us'
+lazyThenUs (USM expr) cont
+  = USM (\us -> let (result, us') = expr us in unUSM (cont result) us')
 
 thenUs_ :: UniqSM a -> UniqSM b -> UniqSM b
-thenUs_ expr cont us
-  = case (expr us) of { (_, us') -> cont us' }
+thenUs_ (USM expr) (USM cont)
+  = USM (\us -> case (expr us) of { (_, us') -> cont us' })
 
 
 returnUs :: a -> UniqSM a
-returnUs result us = (result, us)
+returnUs result = USM (\us -> (result, us))
 
 withUs :: (UniqSupply -> (a, UniqSupply)) -> UniqSM a
-withUs f us = f us     -- Ha ha!
+withUs f = USM (\us -> f us)   -- Ha ha!
                
 getUs :: UniqSM UniqSupply
-getUs us = splitUniqSupply us
+getUs = USM (\us -> splitUniqSupply us)
 
 getUniqueUs :: UniqSM Unique
-getUniqueUs us = case splitUniqSupply us of
-                  (us1,us2) -> (uniqFromSupply us1, us2)
+getUniqueUs = USM (\us -> case splitUniqSupply us of
+                          (us1,us2) -> (uniqFromSupply us1, us2))
 
 getUniquesUs :: UniqSM [Unique]
-getUniquesUs us = case splitUniqSupply us of
-                     (us1,us2) -> (uniqsFromSupply us1, us2)
+getUniquesUs = USM (\us -> case splitUniqSupply us of
+                             (us1,us2) -> (uniqsFromSupply us1, us2))
 \end{code}
 
 \begin{code}