%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[UniqSupply]{The @UniqueSupply@ data type and a (monadic) supply thereof}
\begin{code}
-#include "HsVersions.h"
-
module UniqSupply (
UniqSupply, -- Abstractly
- getUnique, getUniques, -- basic ops
+ uniqFromSupply, uniqsFromSupply, -- basic ops
- UniqSM(..), -- type: unique supply monad
- initUs, thenUs, returnUs,
+ UniqSM, -- type: unique supply monad
+ initUs, thenUs, thenUs_, returnUs, fixUs, getUs, setUs,
+ getUniqueUs, getUniquesUs,
mapUs, mapAndUnzipUs, mapAndUnzip3Us,
thenMaybeUs, mapAccumLUs,
splitUniqSupply
) where
-IMP_Ubiq(){-uitous-}
+#include "HsVersions.h"
import Unique
import Util
-import PreludeGlaST
+import GlaExts
+
+#if __GLASGOW_HASKELL__ < 301
+import IOBase ( IO(..), IOResult(..) )
+#else
+#endif
w2i x = word2Int# x
i2w x = int2Word# x
mkSplitUniqSupply :: Char -> IO UniqSupply
splitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply)
-getUnique :: UniqSupply -> Unique
-getUniques :: Int -> UniqSupply -> [Unique]
+uniqFromSupply :: UniqSupply -> Unique
+uniqsFromSupply :: Int -> UniqSupply -> [Unique]
\end{code}
\begin{code}
-- 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 (I# (w2i (mask# `or#` u#)))
+
+ mk_unique = _ccall_ genSymZh >>= \ (W# u#) ->
+ return (I# (w2i (mask# `or#` u#)))
in
- mk_supply# `thenPrimIO` \ s ->
- return s
+ mk_supply#
splitUniqSupply (MkSplitUniqSupply _ s1 s2) = (s1, s2)
\end{code}
\begin{code}
-getUnique (MkSplitUniqSupply (I# n) _ _) = mkUniqueGrimily n
+uniqFromSupply (MkSplitUniqSupply (I# n) _ _) = mkUniqueGrimily n
-getUniques (I# i) supply = i `get_from` supply
+uniqsFromSupply (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}
%************************************************************************
%************************************************************************
\begin{code}
-type UniqSM result = UniqSupply -> result
+type UniqSM result = UniqSupply -> (result, UniqSupply)
-- 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 = case m init_us of { (r,_) -> r }
{-# INLINE thenUs #-}
{-# INLINE returnUs #-}
@thenUs@ is where we split the @UniqSupply@.
\begin{code}
-thenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
+fixUs :: (a -> UniqSM a) -> UniqSM a
+fixUs m us
+ = (r,us') where (r,us') = m r us
+thenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
thenUs expr cont us
- = case (splitUniqSupply us) of { (s1, s2) ->
- case (expr s1) of { result ->
- cont result s2 }}
-\end{code}
+ = case (expr us) of { (result, us') -> cont result us' }
+
+thenUs_ :: UniqSM a -> UniqSM b -> UniqSM b
+thenUs_ expr cont us
+ = case (expr us) of { (_, us') -> cont us' }
-\begin{code}
returnUs :: a -> UniqSM a
-returnUs result us = result
+returnUs result us = (result, us)
+
+getUs :: UniqSM UniqSupply
+getUs us = (us, panic "getUs: bad supply")
+
+setUs :: UniqSupply -> UniqSM ()
+setUs us old_us = ((), us)
+getUniqueUs :: UniqSM Unique
+getUniqueUs us = case splitUniqSupply us of
+ (us1,us2) -> (uniqFromSupply us1, us2)
+
+getUniquesUs :: Int -> UniqSM [Unique]
+getUniquesUs n us = case splitUniqSupply us of
+ (us1,us2) -> (uniqsFromSupply n us1, us2)
+\end{code}
+
+\begin{code}
mapUs :: (a -> UniqSM b) -> [a] -> UniqSM [b]
mapUs f [] = returnUs []