{- (c) The University of Glasgow 2006 (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 -} {-# LANGUAGE CPP #-} {-# LANGUAGE PatternSynonyms #-} #if !defined(GHC_LOADED_INTO_GHCI) {-# LANGUAGE UnboxedTuples #-} #endif module UniqSupply ( -- * Main data type UniqSupply, -- Abstractly -- ** Operations on supplies uniqFromSupply, uniqsFromSupply, -- basic ops takeUniqFromSupply, mkSplitUniqSupply, splitUniqSupply, listSplitUniqSupply, splitUniqSupply3, splitUniqSupply4, -- * Unique supply monad and its abstraction UniqSM, MonadUnique(..), liftUs, -- ** Operations on the monad initUs, initUs_, lazyThenUs, lazyMapUs, getUniqueSupplyM3, -- * Set supply strategy initUniqSupply ) where import GhcPrelude import Unique import PlainPanic (panic) import GHC.IO import MonadUtils import Control.Monad import Data.Bits import Data.Char import Control.Monad.Fail as Fail #include "Unique.h" {- ************************************************************************ * * \subsection{Splittable Unique supply: @UniqSupply@} * * ************************************************************************ -} -- | Unique Supply -- -- A value of type 'UniqSupply' is unique, and it can -- supply /one/ distinct 'Unique'. Also, from the supply, one can -- also manufacture an arbitrary number of further 'UniqueSupply' values, -- which will be distinct from the first and from all others. data UniqSupply = MkSplitUniqSupply {-# UNPACK #-} !Int -- make the Unique with this UniqSupply UniqSupply -- when split => these two supplies mkSplitUniqSupply :: Char -> IO UniqSupply -- ^ Create a unique supply out of thin air. The character given must -- be distinct from those of all calls to this function in the compiler -- for the values generated to be truly unique. splitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply) -- ^ Build two 'UniqSupply' from a single one, each of which -- can supply its own 'Unique'. listSplitUniqSupply :: UniqSupply -> [UniqSupply] -- ^ Create an infinite list of 'UniqSupply' from a single one uniqFromSupply :: UniqSupply -> Unique -- ^ Obtain the 'Unique' from this particular 'UniqSupply' uniqsFromSupply :: UniqSupply -> [Unique] -- Infinite -- ^ Obtain an infinite list of 'Unique' that can be generated by constant splitting of the supply takeUniqFromSupply :: UniqSupply -> (Unique, UniqSupply) -- ^ Obtain the 'Unique' from this particular 'UniqSupply', and a new supply mkSplitUniqSupply :: Char -> IO UniqSupply mkSplitUniqSupply c :: Char c = case Char -> Int ord Char c Int -> Int -> Int forall a. Bits a => a -> Int -> a `shiftL` Int uNIQUE_BITS of mask :: Int mask -> let -- here comes THE MAGIC: -- This is one of the most hammered bits in the whole compiler mk_supply :: IO UniqSupply mk_supply -- NB: Use unsafeInterleaveIO for thread-safety. = IO UniqSupply -> IO UniqSupply forall a. IO a -> IO a unsafeInterleaveIO ( IO Int genSym IO Int -> (Int -> IO UniqSupply) -> IO UniqSupply forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b >>= \ u :: Int u -> IO UniqSupply mk_supply IO UniqSupply -> (UniqSupply -> IO UniqSupply) -> IO UniqSupply forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b >>= \ s1 :: UniqSupply s1 -> IO UniqSupply mk_supply IO UniqSupply -> (UniqSupply -> IO UniqSupply) -> IO UniqSupply forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b >>= \ s2 :: UniqSupply s2 -> UniqSupply -> IO UniqSupply forall (m :: * -> *) a. Monad m => a -> m a return (Int -> UniqSupply -> UniqSupply -> UniqSupply MkSplitUniqSupply (Int mask Int -> Int -> Int forall a. Bits a => a -> a -> a .|. Int u) UniqSupply s1 UniqSupply s2) ) in IO UniqSupply mk_supply foreign import ccall unsafe "genSym" genSym :: IO Int foreign import ccall unsafe "initGenSym" initUniqSupply :: Int -> Int -> IO () splitUniqSupply :: UniqSupply -> (UniqSupply, UniqSupply) splitUniqSupply (MkSplitUniqSupply _ s1 :: UniqSupply s1 s2 :: UniqSupply s2) = (UniqSupply s1, UniqSupply s2) listSplitUniqSupply :: UniqSupply -> [UniqSupply] listSplitUniqSupply (MkSplitUniqSupply _ s1 :: UniqSupply s1 s2 :: UniqSupply s2) = UniqSupply s1 UniqSupply -> [UniqSupply] -> [UniqSupply] forall a. a -> [a] -> [a] : UniqSupply -> [UniqSupply] listSplitUniqSupply UniqSupply s2 uniqFromSupply :: UniqSupply -> Unique uniqFromSupply (MkSplitUniqSupply n :: Int n _ _) = Int -> Unique mkUniqueGrimily Int n uniqsFromSupply :: UniqSupply -> [Unique] uniqsFromSupply (MkSplitUniqSupply n :: Int n _ s2 :: UniqSupply s2) = Int -> Unique mkUniqueGrimily Int n Unique -> [Unique] -> [Unique] forall a. a -> [a] -> [a] : UniqSupply -> [Unique] uniqsFromSupply UniqSupply s2 takeUniqFromSupply :: UniqSupply -> (Unique, UniqSupply) takeUniqFromSupply (MkSplitUniqSupply n :: Int n s1 :: UniqSupply s1 _) = (Int -> Unique mkUniqueGrimily Int n, UniqSupply s1) -- | Build three 'UniqSupply' from a single one, -- each of which can supply its own unique splitUniqSupply3 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply) splitUniqSupply3 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply) splitUniqSupply3 us :: UniqSupply us = (UniqSupply us1, UniqSupply us2, UniqSupply us3) where (us1 :: UniqSupply us1, us' :: UniqSupply us') = UniqSupply -> (UniqSupply, UniqSupply) splitUniqSupply UniqSupply us (us2 :: UniqSupply us2, us3 :: UniqSupply us3) = UniqSupply -> (UniqSupply, UniqSupply) splitUniqSupply UniqSupply us' -- | Build four 'UniqSupply' from a single one, -- each of which can supply its own unique splitUniqSupply4 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply, UniqSupply) splitUniqSupply4 :: UniqSupply -> (UniqSupply, UniqSupply, UniqSupply, UniqSupply) splitUniqSupply4 us :: UniqSupply us = (UniqSupply us1, UniqSupply us2, UniqSupply us3, UniqSupply us4) where (us1 :: UniqSupply us1, us2 :: UniqSupply us2, us' :: UniqSupply us') = UniqSupply -> (UniqSupply, UniqSupply, UniqSupply) splitUniqSupply3 UniqSupply us (us3 :: UniqSupply us3, us4 :: UniqSupply us4) = UniqSupply -> (UniqSupply, UniqSupply) splitUniqSupply UniqSupply us' {- ************************************************************************ * * \subsubsection[UniqSupply-monad]{@UniqSupply@ monad: @UniqSM@} * * ************************************************************************ -} -- Avoids using unboxed tuples when loading into GHCi #if !defined(GHC_LOADED_INTO_GHCI) type UniqResult result = (# result, UniqSupply #) pattern UniqResult :: a -> b -> (# a, b #) pattern $bUniqResult :: a -> b -> (# a, b #) $mUniqResult :: forall r a b. (# a, b #) -> (a -> b -> r) -> (Void# -> r) -> r UniqResult x y = (# x, y #) {-# COMPLETE UniqResult #-} #else data UniqResult result = UniqResult !result {-# UNPACK #-} !UniqSupply #endif -- | A monad which just gives the ability to obtain 'Unique's newtype UniqSM result = USM { UniqSM result -> UniqSupply -> UniqResult result unUSM :: UniqSupply -> UniqResult result } instance Monad UniqSM where >>= :: UniqSM a -> (a -> UniqSM b) -> UniqSM b (>>=) = UniqSM a -> (a -> UniqSM b) -> UniqSM b forall a b. UniqSM a -> (a -> UniqSM b) -> UniqSM b thenUs >> :: UniqSM a -> UniqSM b -> UniqSM b (>>) = UniqSM a -> UniqSM b -> UniqSM b forall (f :: * -> *) a b. Applicative f => f a -> f b -> f b (*>) instance Functor UniqSM where fmap :: (a -> b) -> UniqSM a -> UniqSM b fmap f :: a -> b f (USM x :: UniqSupply -> UniqResult a x) = (UniqSupply -> UniqResult b) -> UniqSM b forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> case UniqSupply -> UniqResult a x UniqSupply us0 of UniqResult r :: a r us1 :: UniqSupply us1 -> b -> UniqSupply -> UniqResult b forall a b. a -> b -> (# a, b #) UniqResult (a -> b f a r) UniqSupply us1) instance Applicative UniqSM where pure :: a -> UniqSM a pure = a -> UniqSM a forall a. a -> UniqSM a returnUs (USM f :: UniqSupply -> UniqResult (a -> b) f) <*> :: UniqSM (a -> b) -> UniqSM a -> UniqSM b <*> (USM x :: UniqSupply -> UniqResult a x) = (UniqSupply -> UniqResult b) -> UniqSM b forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM ((UniqSupply -> UniqResult b) -> UniqSM b) -> (UniqSupply -> UniqResult b) -> UniqSM b forall a b. (a -> b) -> a -> b $ \us0 :: UniqSupply us0 -> case UniqSupply -> UniqResult (a -> b) f UniqSupply us0 of UniqResult ff :: a -> b ff us1 :: UniqSupply us1 -> case UniqSupply -> UniqResult a x UniqSupply us1 of UniqResult xx :: a xx us2 :: UniqSupply us2 -> b -> UniqSupply -> UniqResult b forall a b. a -> b -> (# a, b #) UniqResult (a -> b ff a xx) UniqSupply us2 *> :: UniqSM a -> UniqSM b -> UniqSM b (*>) = UniqSM a -> UniqSM b -> UniqSM b forall a b. UniqSM a -> UniqSM b -> UniqSM b thenUs_ -- TODO: try to get rid of this instance instance Fail.MonadFail UniqSM where fail :: String -> UniqSM a fail = String -> UniqSM a forall a. String -> a panic -- | Run the 'UniqSM' action, returning the final 'UniqSupply' initUs :: UniqSupply -> UniqSM a -> (a, UniqSupply) initUs :: UniqSupply -> UniqSM a -> (a, UniqSupply) initUs init_us :: UniqSupply init_us m :: UniqSM a m = case UniqSM a -> UniqSupply -> UniqResult a forall result. UniqSM result -> UniqSupply -> UniqResult result unUSM UniqSM a m UniqSupply init_us of { UniqResult r :: a r us :: UniqSupply us -> (a r, UniqSupply us) } -- | Run the 'UniqSM' action, discarding the final 'UniqSupply' initUs_ :: UniqSupply -> UniqSM a -> a initUs_ :: UniqSupply -> UniqSM a -> a initUs_ init_us :: UniqSupply init_us m :: UniqSM a m = case UniqSM a -> UniqSupply -> UniqResult a forall result. UniqSM result -> UniqSupply -> UniqResult result unUSM UniqSM a m UniqSupply init_us of { UniqResult r :: a r _ -> a r } {-# INLINE thenUs #-} {-# INLINE lazyThenUs #-} {-# INLINE returnUs #-} {-# INLINE splitUniqSupply #-} -- @thenUs@ is where we split the @UniqSupply@. liftUSM :: UniqSM a -> UniqSupply -> (a, UniqSupply) liftUSM :: UniqSM a -> UniqSupply -> (a, UniqSupply) liftUSM (USM m :: UniqSupply -> UniqResult a m) us0 :: UniqSupply us0 = case UniqSupply -> UniqResult a m UniqSupply us0 of UniqResult a :: a a us1 :: UniqSupply us1 -> (a a, UniqSupply us1) instance MonadFix UniqSM where mfix :: (a -> UniqSM a) -> UniqSM a mfix m :: a -> UniqSM a m = (UniqSupply -> UniqResult a) -> UniqSM a forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> let (r :: a r,us1 :: UniqSupply us1) = UniqSM a -> UniqSupply -> (a, UniqSupply) forall a. UniqSM a -> UniqSupply -> (a, UniqSupply) liftUSM (a -> UniqSM a m a r) UniqSupply us0 in a -> UniqSupply -> UniqResult a forall a b. a -> b -> (# a, b #) UniqResult a r UniqSupply us1) thenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b thenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b thenUs (USM expr :: UniqSupply -> UniqResult a expr) cont :: a -> UniqSM b cont = (UniqSupply -> UniqResult b) -> UniqSM b forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> case (UniqSupply -> UniqResult a expr UniqSupply us0) of UniqResult result :: a result us1 :: UniqSupply us1 -> UniqSM b -> UniqSupply -> UniqResult b forall result. UniqSM result -> UniqSupply -> UniqResult result unUSM (a -> UniqSM b cont a result) UniqSupply us1) lazyThenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b lazyThenUs :: UniqSM a -> (a -> UniqSM b) -> UniqSM b lazyThenUs expr :: UniqSM a expr cont :: a -> UniqSM b cont = (UniqSupply -> UniqResult b) -> UniqSM b forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> let (result :: a result, us1 :: UniqSupply us1) = UniqSM a -> UniqSupply -> (a, UniqSupply) forall a. UniqSM a -> UniqSupply -> (a, UniqSupply) liftUSM UniqSM a expr UniqSupply us0 in UniqSM b -> UniqSupply -> UniqResult b forall result. UniqSM result -> UniqSupply -> UniqResult result unUSM (a -> UniqSM b cont a result) UniqSupply us1) thenUs_ :: UniqSM a -> UniqSM b -> UniqSM b thenUs_ :: UniqSM a -> UniqSM b -> UniqSM b thenUs_ (USM expr :: UniqSupply -> UniqResult a expr) (USM cont :: UniqSupply -> UniqResult b cont) = (UniqSupply -> UniqResult b) -> UniqSM b forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> case (UniqSupply -> UniqResult a expr UniqSupply us0) of { UniqResult _ us1 :: UniqSupply us1 -> UniqSupply -> UniqResult b cont UniqSupply us1 }) returnUs :: a -> UniqSM a returnUs :: a -> UniqSM a returnUs result :: a result = (UniqSupply -> UniqResult a) -> UniqSM a forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us :: UniqSupply us -> a -> UniqSupply -> UniqResult a forall a b. a -> b -> (# a, b #) UniqResult a result UniqSupply us) getUs :: UniqSM UniqSupply getUs :: UniqSM UniqSupply getUs = (UniqSupply -> UniqResult UniqSupply) -> UniqSM UniqSupply forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> case UniqSupply -> (UniqSupply, UniqSupply) splitUniqSupply UniqSupply us0 of (us1 :: UniqSupply us1,us2 :: UniqSupply us2) -> UniqSupply -> UniqSupply -> UniqResult UniqSupply forall a b. a -> b -> (# a, b #) UniqResult UniqSupply us1 UniqSupply us2) -- | A monad for generating unique identifiers class Monad m => MonadUnique m where -- | Get a new UniqueSupply getUniqueSupplyM :: m UniqSupply -- | Get a new unique identifier getUniqueM :: m Unique -- | Get an infinite list of new unique identifiers getUniquesM :: m [Unique] -- This default definition of getUniqueM, while correct, is not as -- efficient as it could be since it needlessly generates and throws away -- an extra Unique. For your instances consider providing an explicit -- definition for 'getUniqueM' which uses 'takeUniqFromSupply' directly. getUniqueM = (UniqSupply -> Unique) -> m UniqSupply -> m Unique forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r liftM UniqSupply -> Unique uniqFromSupply m UniqSupply forall (m :: * -> *). MonadUnique m => m UniqSupply getUniqueSupplyM getUniquesM = (UniqSupply -> [Unique]) -> m UniqSupply -> m [Unique] forall (m :: * -> *) a1 r. Monad m => (a1 -> r) -> m a1 -> m r liftM UniqSupply -> [Unique] uniqsFromSupply m UniqSupply forall (m :: * -> *). MonadUnique m => m UniqSupply getUniqueSupplyM instance MonadUnique UniqSM where getUniqueSupplyM :: UniqSM UniqSupply getUniqueSupplyM = UniqSM UniqSupply getUs getUniqueM :: UniqSM Unique getUniqueM = UniqSM Unique getUniqueUs getUniquesM :: UniqSM [Unique] getUniquesM = UniqSM [Unique] getUniquesUs getUniqueSupplyM3 :: MonadUnique m => m (UniqSupply, UniqSupply, UniqSupply) getUniqueSupplyM3 :: m (UniqSupply, UniqSupply, UniqSupply) getUniqueSupplyM3 = (UniqSupply -> UniqSupply -> UniqSupply -> (UniqSupply, UniqSupply, UniqSupply)) -> m UniqSupply -> m UniqSupply -> m UniqSupply -> m (UniqSupply, UniqSupply, UniqSupply) forall (m :: * -> *) a1 a2 a3 r. Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r liftM3 (,,) m UniqSupply forall (m :: * -> *). MonadUnique m => m UniqSupply getUniqueSupplyM m UniqSupply forall (m :: * -> *). MonadUnique m => m UniqSupply getUniqueSupplyM m UniqSupply forall (m :: * -> *). MonadUnique m => m UniqSupply getUniqueSupplyM liftUs :: MonadUnique m => UniqSM a -> m a liftUs :: UniqSM a -> m a liftUs m :: UniqSM a m = m UniqSupply forall (m :: * -> *). MonadUnique m => m UniqSupply getUniqueSupplyM m UniqSupply -> (UniqSupply -> m a) -> m a forall (m :: * -> *) a b. Monad m => m a -> (a -> m b) -> m b >>= a -> m a forall (m :: * -> *) a. Monad m => a -> m a return (a -> m a) -> (UniqSupply -> a) -> UniqSupply -> m a forall b c a. (b -> c) -> (a -> b) -> a -> c . (UniqSupply -> UniqSM a -> a) -> UniqSM a -> UniqSupply -> a forall a b c. (a -> b -> c) -> b -> a -> c flip UniqSupply -> UniqSM a -> a forall a. UniqSupply -> UniqSM a -> a initUs_ UniqSM a m getUniqueUs :: UniqSM Unique getUniqueUs :: UniqSM Unique getUniqueUs = (UniqSupply -> UniqResult Unique) -> UniqSM Unique forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> case UniqSupply -> (Unique, UniqSupply) takeUniqFromSupply UniqSupply us0 of (u :: Unique u,us1 :: UniqSupply us1) -> Unique -> UniqSupply -> UniqResult Unique forall a b. a -> b -> (# a, b #) UniqResult Unique u UniqSupply us1) getUniquesUs :: UniqSM [Unique] getUniquesUs :: UniqSM [Unique] getUniquesUs = (UniqSupply -> UniqResult [Unique]) -> UniqSM [Unique] forall result. (UniqSupply -> UniqResult result) -> UniqSM result USM (\us0 :: UniqSupply us0 -> case UniqSupply -> (UniqSupply, UniqSupply) splitUniqSupply UniqSupply us0 of (us1 :: UniqSupply us1,us2 :: UniqSupply us2) -> [Unique] -> UniqSupply -> UniqResult [Unique] forall a b. a -> b -> (# a, b #) UniqResult (UniqSupply -> [Unique] uniqsFromSupply UniqSupply us1) UniqSupply us2) -- {-# SPECIALIZE mapM :: (a -> UniqSM b) -> [a] -> UniqSM [b] #-} -- {-# SPECIALIZE mapAndUnzipM :: (a -> UniqSM (b,c)) -> [a] -> UniqSM ([b],[c]) #-} -- {-# SPECIALIZE mapAndUnzip3M :: (a -> UniqSM (b,c,d)) -> [a] -> UniqSM ([b],[c],[d]) #-} lazyMapUs :: (a -> UniqSM b) -> [a] -> UniqSM [b] lazyMapUs :: (a -> UniqSM b) -> [a] -> UniqSM [b] lazyMapUs _ [] = [b] -> UniqSM [b] forall a. a -> UniqSM a returnUs [] lazyMapUs f :: a -> UniqSM b f (x :: a x:xs :: [a] xs) = a -> UniqSM b f a x UniqSM b -> (b -> UniqSM [b]) -> UniqSM [b] forall a b. UniqSM a -> (a -> UniqSM b) -> UniqSM b `lazyThenUs` \ r :: b r -> (a -> UniqSM b) -> [a] -> UniqSM [b] forall a b. (a -> UniqSM b) -> [a] -> UniqSM [b] lazyMapUs a -> UniqSM b f [a] xs UniqSM [b] -> ([b] -> UniqSM [b]) -> UniqSM [b] forall a b. UniqSM a -> (a -> UniqSM b) -> UniqSM b `lazyThenUs` \ rs :: [b] rs -> [b] -> UniqSM [b] forall a. a -> UniqSM a returnUs (b rb -> [b] -> [b] forall a. a -> [a] -> [a] :[b] rs)