uniqFromSupply, uniqsFromSupply, -- basic ops
UniqSM, -- type: unique supply monad
- initUs, thenUs, thenUs_, returnUs, fixUs, getUs, setUs,
+ initUs, initUs_, thenUs, thenUs_, returnUs, fixUs, getUs, withUs,
getUniqueUs, getUniquesUs,
mapUs, mapAndUnzipUs, mapAndUnzip3Us,
thenMaybeUs, mapAccumLUs,
+ lazyThenUs, lazyMapUs,
mkSplitUniqSupply,
splitUniqSupply
#include "HsVersions.h"
import Unique
-import Util
-import GlaExts
-
-#if __GLASGOW_HASKELL__ < 301
-import IOBase ( IO(..), IOResult(..) )
-#else
-#endif
+import GLAEXTS
+import UNSAFE_IO ( unsafeInterleaveIO )
w2i x = word2Int# x
i2w x = int2Word# x
%* *
%************************************************************************
-%************************************************************************
-%* *
-\subsubsection[UniqSupply-type]{@UniqSupply@ type and operations}
-%* *
-%************************************************************************
-
A value of type @UniqSupply@ is unique, and it can
supply {\em one} distinct @Unique@. Also, from the supply, one can
also manufacture an arbitrary number of further @UniqueSupplies@,
splitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply)
uniqFromSupply :: UniqSupply -> Unique
-uniqsFromSupply :: Int -> UniqSupply -> [Unique]
+uniqsFromSupply :: UniqSupply -> [Unique] -- Infinite
\end{code}
\begin{code}
mkSplitUniqSupply (C# c#)
= let
+#if __GLASGOW_HASKELL__ >= 503
+ mask# = (i2w (ord# c#)) `uncheckedShiftL#` (i2w_s 24#)
+#else
mask# = (i2w (ord# c#)) `shiftL#` (i2w_s 24#)
-
+#endif
-- here comes THE MAGIC:
-- This is one of the most hammered bits in the whole compiler
return (MkSplitUniqSupply uniq s1 s2)
)
- mk_unique = _ccall_ genSymZh >>= \ (W# u#) ->
+ mk_unique = genSymZh >>= \ (W# u#) ->
return (I# (w2i (mask# `or#` u#)))
in
mk_supply#
+foreign import ccall unsafe "genSymZh" genSymZh :: IO Word
+
splitUniqSupply (MkSplitUniqSupply _ s1 s2) = (s1, s2)
\end{code}
\begin{code}
-uniqFromSupply (MkSplitUniqSupply (I# n) _ _) = mkUniqueGrimily n
-
-uniqsFromSupply (I# i) supply = i `get_from` supply
- where
- get_from 0# _ = []
- get_from n (MkSplitUniqSupply (I# u) _ s2)
- = mkUniqueGrimily u : get_from (n -# 1#) s2
+uniqFromSupply (MkSplitUniqSupply n _ _) = mkUniqueGrimily n
+uniqsFromSupply (MkSplitUniqSupply n _ s2) = mkUniqueGrimily n : uniqsFromSupply s2
\end{code}
%************************************************************************
\begin{code}
type UniqSM result = UniqSupply -> (result, UniqSupply)
--- the initUs function also returns the final UniqSupply
+-- 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 :: UniqSupply -> UniqSM a -> a
-
-initUs init_us m = case m init_us of { (r,_) -> r }
+initUs_ :: UniqSupply -> UniqSM a -> a
+initUs_ init_us m = case m init_us of { (r,us) -> r }
{-# INLINE thenUs #-}
+{-# INLINE lazyThenUs #-}
{-# INLINE returnUs #-}
{-# INLINE splitUniqSupply #-}
\end{code}
thenUs expr cont us
= case (expr us) of { (result, us') -> cont result us' }
+lazyThenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b
+lazyThenUs expr cont us
+ = let (result, us') = expr us in cont result us'
+
thenUs_ :: UniqSM a -> UniqSM b -> UniqSM b
thenUs_ expr cont us
= case (expr us) of { (_, us') -> cont us' }
+
returnUs :: a -> UniqSM a
returnUs result us = (result, us)
+withUs :: (UniqSupply -> (a, UniqSupply)) -> UniqSM a
+withUs f us = f us -- Ha ha!
+
getUs :: UniqSM UniqSupply
-getUs us = (us, panic "getUs: bad supply")
-
-setUs :: UniqSupply -> UniqSM ()
-setUs us old_us = ((), us)
+getUs us = splitUniqSupply 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)
+getUniquesUs :: UniqSM [Unique]
+getUniquesUs us = case splitUniqSupply us of
+ (us1,us2) -> (uniqsFromSupply us1, us2)
\end{code}
\begin{code}
mapUs :: (a -> UniqSM b) -> [a] -> UniqSM [b]
-
mapUs f [] = returnUs []
mapUs f (x:xs)
= f x `thenUs` \ r ->
mapUs f xs `thenUs` \ rs ->
returnUs (r:rs)
+lazyMapUs :: (a -> UniqSM b) -> [a] -> UniqSM [b]
+lazyMapUs f [] = returnUs []
+lazyMapUs f (x:xs)
+ = f x `lazyThenUs` \ r ->
+ lazyMapUs f xs `lazyThenUs` \ rs ->
+ returnUs (r:rs)
+
mapAndUnzipUs :: (a -> UniqSM (b,c)) -> [a] -> UniqSM ([b],[c])
mapAndUnzip3Us :: (a -> UniqSM (b,c,d)) -> [a] -> UniqSM ([b],[c],[d])