monad-par-extras-0.3.3/0000755000000000000000000000000012170056302013061 5ustar0000000000000000monad-par-extras-0.3.3/monad-par-extras.cabal0000644000000000000000000000407212170056302017232 0ustar0000000000000000Name: monad-par-extras Version: 0.3.3 Synopsis: Combinators and extra features for Par monads -- Version history: -- 0.3 : Factored/reorganized modules. This module is a spinoff of -- the original monad-par -- 0.3.2 : Relax depends. Description: The modules below provide additional data structures, and other added capabilities layered on top of the 'Par' monad. -- * Finish These -- * Module Descriptions Homepage: https://github.com/simonmar/monad-par License: BSD3 License-file: LICENSE Author: Ryan Newton, Simon Marlow Maintainer: Ryan Newton Copyright: (c) Ryan Newton 2012 Stability: Experimental Category: Control,Parallelism,Monads Build-type: Simple Cabal-version: >=1.8 Library Exposed-modules: -- A collection of combinators for common parallel -- patterns and data structure traversals: Control.Monad.Par.Combinator, -- Deprecated AList interface Control.Monad.Par.AList, -- State on top of Par is generally useful, but experimental Control.Monad.Par.State, -- Deterministic RNG needs more testing. Control.Monad.Par.RNG Other-modules: -- Pedigree is experimental, but potentially useful for -- many purposes such as assigning unique, reproducable -- identifiers to IVars Control.Monad.Par.Pedigree Build-depends: base >= 4 && < 5 -- This provides the interface which monad-par implements: , abstract-par >= 0.3 && < 0.4 , cereal >= 0.3 , deepseq >= 1.3 , random >= 1.0 , mtl >= 2.0 , transformers >= 0.2 ghc-options: -O2 Other-modules: monad-par-extras-0.3.3/LICENSE0000644000000000000000000000275512170056302014077 0ustar0000000000000000Copyright Simon Marlow 2011 All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of Simon Marlow nor the names of other contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. monad-par-extras-0.3.3/Setup.hs0000644000000000000000000000011012170056302014505 0ustar0000000000000000#!/usr/bin/env runhaskell import Distribution.Simple main = defaultMain monad-par-extras-0.3.3/Control/0000755000000000000000000000000012170056302014501 5ustar0000000000000000monad-par-extras-0.3.3/Control/Monad/0000755000000000000000000000000012170056302015537 5ustar0000000000000000monad-par-extras-0.3.3/Control/Monad/Par/0000755000000000000000000000000012170056302016261 5ustar0000000000000000monad-par-extras-0.3.3/Control/Monad/Par/RNG.hs0000644000000000000000000000361612170056302017251 0ustar0000000000000000{-# LANGUAGE FlexibleInstances, UndecidableInstances #-} -- | This module defines another Par-related class to capture the -- random number generation capability. -- -- The `rand` operation provides deterministic parallel random -- number generation from within a Par monad. -- -- Most likely one will simply use the `ParRand` the instance -- provided in this file, which is based on a state transformer -- carrying the random generator. module Control.Monad.Par.RNG ( ParRand(..), runParRand, ParRandStd ) where import System.Random import Control.Exception import Control.Monad.Par.Class import Control.Monad.Par.State import Control.Monad.Trans import Control.Monad.Trans.State.Strict as S -- | A `ParRand` monad is a Par monad with support for random number generation.. class ParRand p where rand :: Random a => p a -- This can be more efficient: randInt :: p Int randInt = rand -- | Trivial instance. instance RandomGen g => SplittableState g where splitState = split -- | The most straightforward way to get a `ParRand` monad: carry a -- RNG in a state transformer. instance (ParFuture fut p, RandomGen g) => ParRand (StateT g p) where rand = do g <- S.get let (x,g') = random g S.put g' return x randInt = do g <- S.get let (x,g') = next g S.put g' return x -- An alternative is for these operators to be standalone without a class: -- rand :: (ParFuture p fut, RandomGen g, Random a) => StateT g p a -- randInt :: (ParFuture p fut, RandomGen g) => StateT g p Int -- runParRand :: ParRand p => (p a -> a) -> p a -> IO a runParRand :: ParFuture fut p => (p a -> a) -> StateT StdGen p a -> IO a runParRand runPar m = do g <- newStdGen evaluate (runPar (evalStateT m g)) -- | A convenience type for the most standard type ParRandStd par a = StateT StdGen par a monad-par-extras-0.3.3/Control/Monad/Par/Combinator.hs0000644000000000000000000001417112170056302020716 0ustar0000000000000000{-# LANGUAGE BangPatterns #-} {-| A collection of useful parallel combinators based on top of a 'Par' monad. In particular, this module provides higher order functions for traversing data structures in parallel. -} module Control.Monad.Par.Combinator ( parMap, parMapM, parMapReduceRangeThresh, parMapReduceRange, InclusiveRange(..), parFor ) where import Control.DeepSeq import Data.Traversable import Control.Monad as M hiding (mapM, sequence, join) import Prelude hiding (mapM, sequence, head,tail) import GHC.Conc (numCapabilities) import Control.Monad.Par.Class -- ----------------------------------------------------------------------------- -- Parallel maps over Traversable data structures -- | Applies the given function to each element of a data structure -- in parallel (fully evaluating the results), and returns a new data -- structure containing the results. -- -- > parMap f xs = mapM (spawnP . f) xs >>= mapM get -- -- @parMap@ is commonly used for lists, where it has this specialised type: -- -- > parMap :: NFData b => (a -> b) -> [a] -> Par [b] -- parMap :: (Traversable t, NFData b, ParFuture iv p) => (a -> b) -> t a -> p (t b) parMap f xs = mapM (spawnP . f) xs >>= mapM get -- | Like 'parMap', but the function is a @Par@ monad operation. -- -- > parMapM f xs = mapM (spawn . f) xs >>= mapM get -- parMapM :: (Traversable t, NFData b, ParFuture iv p) => (a -> p b) -> t a -> p (t b) parMapM f xs = mapM (spawn . f) xs >>= mapM get -- TODO: parBuffer -- -------------------------------------------------------------------------------- -- TODO: Perhaps should introduce a class for the "splittable range" concept. data InclusiveRange = InclusiveRange Int Int -- | Computes a binary map\/reduce over a finite range. The range is -- recursively split into two, the result for each half is computed in -- parallel, and then the two results are combined. When the range -- reaches the threshold size, the remaining elements of the range are -- computed sequentially. -- -- For example, the following is a parallel implementation of -- -- > foldl (+) 0 (map (^2) [1..10^6]) -- -- > parMapReduceRangeThresh 100 (InclusiveRange 1 (10^6)) -- > (\x -> return (x^2)) -- > (\x y -> return (x+y)) -- > 0 -- parMapReduceRangeThresh :: (NFData a, ParFuture iv p) => Int -- ^ threshold -> InclusiveRange -- ^ range over which to calculate -> (Int -> p a) -- ^ compute one result -> (a -> a -> p a) -- ^ combine two results (associative) -> a -- ^ initial result -> p a parMapReduceRangeThresh threshold (InclusiveRange min max) fn binop init = loop min max where loop min max | max - min <= threshold = let mapred a b = do x <- fn b; result <- a `binop` x return result in foldM mapred init [min..max] | otherwise = do let mid = min + ((max - min) `quot` 2) rght <- spawn $ loop (mid+1) max l <- loop min mid r <- get rght l `binop` r -- How many tasks per process should we aim for? Higher numbers -- improve load balance but put more pressure on the scheduler. auto_partition_factor :: Int auto_partition_factor = 4 -- | \"Auto-partitioning\" version of 'parMapReduceRangeThresh' that chooses the threshold based on -- the size of the range and the number of processors.. parMapReduceRange :: (NFData a, ParFuture iv p) => InclusiveRange -> (Int -> p a) -> (a -> a -> p a) -> a -> p a parMapReduceRange (InclusiveRange start end) fn binop init = loop (length segs) segs where segs = splitInclusiveRange (auto_partition_factor * numCapabilities) (start,end) loop 1 [(st,en)] = let mapred a b = do x <- fn b; result <- a `binop` x return result in foldM mapred init [st..en] loop n segs = let half = n `quot` 2 (left,right) = splitAt half segs in do l <- spawn$ loop half left r <- loop (n-half) right l' <- get l l' `binop` r -- TODO: A version that works for any splittable input domain. In this case -- the "threshold" is a predicate on inputs. -- parMapReduceRangeGeneric :: (inp -> Bool) -> (inp -> Maybe (inp,inp)) -> inp -> -- Experimental: -- | Parallel for-loop over an inclusive range. Semantically equivalent -- to -- -- > parFor (InclusiveRange n m) f = forM_ [n..m] f -- -- except that the implementation will split the work into an -- unspecified number of subtasks in an attempt to gain parallelism. -- The exact number of subtasks is chosen at runtime, and is probably -- a small multiple of the available number of processors. -- -- Strictly speaking the semantics of 'parFor' depends on the -- number of processors, and its behaviour is therefore not -- deterministic. However, a good rule of thumb is to not have any -- interdependencies between the elements; if this rule is followed -- then @parFor@ has deterministic semantics. One easy way to follow -- this rule is to only use 'put' or 'put_' in @f@, never 'get'. parFor :: (ParFuture iv p) => InclusiveRange -> (Int -> p ()) -> p () parFor (InclusiveRange start end) body = do let run (x,y) = for_ x (y+1) body range_segments = splitInclusiveRange (4*numCapabilities) (start,end) vars <- M.forM range_segments (\ pr -> spawn_ (run pr)) M.mapM_ get vars return () splitInclusiveRange :: Int -> (Int, Int) -> [(Int, Int)] splitInclusiveRange pieces (start,end) = map largepiece [0..remain-1] ++ map smallpiece [remain..pieces-1] where len = end - start + 1 -- inclusive [start,end] (portion, remain) = len `quotRem` pieces largepiece i = let offset = start + (i * (portion + 1)) in (offset, offset + portion) smallpiece i = let offset = start + (i * portion) + remain in (offset, offset + portion - 1) -- My own forM for numeric ranges (not requiring deforestation optimizations). -- Inclusive start, exclusive end. {-# INLINE for_ #-} for_ :: Monad m => Int -> Int -> (Int -> m ()) -> m () for_ start end _fn | start > end = error "for_: start is greater than end" for_ start end fn = loop start where loop !i | i == end = return () | otherwise = do fn i; loop (i+1) monad-par-extras-0.3.3/Control/Monad/Par/AList.hs0000644000000000000000000002106612170056302017636 0ustar0000000000000000{-# LANGUAGE CPP, DeriveDataTypeable #-} {-# OPTIONS_GHC -Wall -fno-warn-name-shadowing -fwarn-unused-imports #-} -- | This module defines the 'AList' type, a list that supports -- constant-time append, and is therefore ideal for building the -- result of tree-shaped parallel computations. module Control.Monad.Par.AList {-# DEPRECATED "This structure does not perform well, and will be removed in future versions" #-} ( -- * The 'AList' type and operations AList(..), empty, singleton, cons, head, tail, length, null, append, toList, fromList, fromListBalanced, -- * Regular (non-parallel) Combinators filter, map, partition, -- * Operations to build 'AList's in the 'Par' monad parBuildThresh, parBuildThreshM, parBuild, parBuildM, -- * Inspect and modify the internal structure of an AList tree depth, balance ) where import Control.DeepSeq import Prelude hiding (length,head,tail,null,map,filter) import qualified Prelude as P import qualified Data.List as L import qualified Control.Monad.Par.Combinator as C import Control.Monad.Par.Class import Data.Typeable import qualified Data.Serialize as S ---------------------------------------------------------------------------------------------------- -- | List that support constant-time append (sometimes called -- join-lists). data AList a = ANil | ASing a | Append (AList a) (AList a) | AList [a] deriving (Typeable) -- TODO -- Add vectors. instance NFData a => NFData (AList a) where rnf ANil = () rnf (ASing a) = rnf a rnf (Append l r) = rnf l `seq` rnf r rnf (AList l) = rnf l instance Show a => Show (AList a) where show al = "fromList "++ show (toList al) -- TODO: Better Serialization instance S.Serialize a => S.Serialize (AList a) where put al = S.put (toList al) get = do x <- S.get return (fromList x) ---------------------------------------------------------------------------------------------------- {-# INLINE append #-} -- | /O(1)/ Append two 'AList's append :: AList a -> AList a -> AList a append ANil r = r append l ANil = l append l r = Append l r {-# INLINE empty #-} -- | /O(1)/ an empty 'AList' empty :: AList a empty = ANil {-# INLINE singleton #-} -- | /O(1)/ a singleton 'AList' singleton :: a -> AList a singleton = ASing {-# INLINE fromList #-} -- | /O(1)/ convert an ordinary list to an 'AList' fromList :: [a] -> AList a fromList = AList -- | Convert an ordinary list, but do so using 'Append' and -- 'ASing' rather than 'AList' fromListBalanced :: [a] -> AList a fromListBalanced xs = go xs (P.length xs) where go _ 0 = ANil go ls 1 = case ls of (h:_) -> ASing h [] -> error "the impossible happened" go ls n = let (q,r) = quotRem n 2 in Append (go ls q) (go (drop q ls) (q+r)) -- | Balance the tree representation of an AList. balance :: AList a -> AList a balance = fromListBalanced . toList -- This would be much better if ALists tracked their size. {-# INLINE cons #-} -- | /O(1)/ prepend an element cons :: a -> AList a -> AList a cons x ANil = ASing x cons x al = Append (ASing x) al -- If we tracked length perhaps this could make an effort at balance. -- | /O(n)/ take the head element of an 'AList' -- -- NB. linear-time, because the list might look like this: -- -- > (((... `append` a) `append` b) `append` c) -- head :: AList a -> a head al = case loop al of Just x -> x Nothing -> error "cannot take head of an empty AList" where -- Alas there are an infinite number of representations for null: loop al = case al of Append l r -> case loop l of x@(Just _) -> x Nothing -> loop r ASing x -> Just x AList (h:_) -> Just h AList [] -> Nothing ANil -> Nothing -- | /O(n)/ take the tail element of an 'AList' tail :: AList a -> AList a tail al = case loop al of Just x -> x Nothing -> error "cannot take tail of an empty AList" where loop al = case al of Append l r -> case loop l of (Just x) -> Just (Append x r) Nothing -> loop r ASing _ -> Just ANil AList (_:t) -> Just (AList t) AList [] -> Nothing ANil -> Nothing -- | /O(n)/ find the length of an 'AList' length :: AList a -> Int length ANil = 0 length (ASing _) = 1 length (Append l r) = length l + length r length (AList l) = P.length l {-# INLINE null #-} -- | /O(n)/ returns 'True' if the 'AList' is empty null :: AList a -> Bool null = (==0) . length -- | /O(n)/ converts an 'AList' to an ordinary list toList :: AList a -> [a] toList a = go a [] where go ANil rest = rest go (ASing a) rest = a : rest go (Append l r) rest = go l $! go r rest go (AList xs) rest = xs ++ rest partition :: (a -> Bool) -> AList a -> (AList a, AList a) partition p a = go a (ANil, ANil) where go ANil acc = acc go (ASing a) (ys, ns) | p a = (a `cons` ys, ns) go (ASing a) (ys, ns) | otherwise = (ys, a `cons` ns) go (Append l r) acc = go l $! go r acc go (AList xs) (ys, ns) = (AList ys' `append` ys, AList ns' `append` ns) where (ys', ns') = L.partition p xs depth :: AList a -> Int depth ANil = 0 depth (ASing _) = 1 depth (AList _) = 1 depth (Append l r) = 1 + max (depth l) (depth r) -- The filter operation compacts dead space in the tree that would be -- left by ANil nodes. filter :: (a -> Bool) -> AList a -> AList a filter p l = loop l where loop ANil = ANil loop o@(ASing x) = if p x then o else ANil loop (AList ls) = AList$ P.filter p ls loop (Append x y) = let l = loop x r = loop y in case (l,r) of (ANil,ANil) -> ANil (ANil,y) -> y (x,ANil) -> x (x,y) -> Append x y -- | The usual `map` operation. map :: (a -> b) -> AList a -> AList b map _ ANil = ANil map f (ASing x) = ASing (f x) map f (AList l) = AList (P.map f l) map f (Append x y) = Append (map f x) (map f y) -------------------------------------------------------------------------------- -- * Combinators built on top of a Par monad. -- | A parMap over an AList can result in more balanced parallelism than -- the default parMap over Traversable data types. -- parMap :: NFData b => (a -> b) -> AList a -> Par (AList b) -- | Build a balanced 'AList' in parallel, constructing each element as a -- function of its index. The threshold argument provides control -- over the degree of parallelism. It indicates under what number -- of elements the build process should switch from parallel to -- serial. parBuildThresh :: (NFData a, ParFuture f p) => Int -> C.InclusiveRange -> (Int -> a) -> p (AList a) parBuildThresh threshold range fn = C.parMapReduceRangeThresh threshold range (return . singleton . fn) appendM empty -- | Variant of 'parBuildThresh' in which the element-construction function is itself a 'Par' computation. parBuildThreshM :: (NFData a, ParFuture f p) => Int -> C.InclusiveRange -> (Int -> p a) -> p (AList a) parBuildThreshM threshold range fn = C.parMapReduceRangeThresh threshold range (\x -> fn x >>= return . singleton) appendM empty -- | \"Auto-partitioning\" version of 'parBuildThresh' that chooses the threshold based on -- the size of the range and the number of processors.. parBuild :: (NFData a, ParFuture f p) => C.InclusiveRange -> (Int -> a) -> p (AList a) parBuild range fn = C.parMapReduceRange range (return . singleton . fn) appendM empty -- | like 'parBuild', but the construction function is monadic parBuildM :: (NFData a, ParFuture f p) => C.InclusiveRange -> (Int -> p a) -> p (AList a) parBuildM range fn = C.parMapReduceRange range (\x -> fn x >>= return . singleton) appendM empty -------------------------------------------------------------------------------- -- TODO: Provide a strategy for @par@-based maps: -- TODO: tryHead -- returns Maybe -- TODO: headTail -- returns head and tail, -- i.e. if we're doing O(N) work, don't do it twice. -- FIXME: Could be more efficient: instance Eq a => Eq (AList a) where a == b = toList a == toList b -- TODO: Finish me: -- instance F.Foldable AList where -- foldr fn init al = -- case al of -- ANil -> -- instance Functor AList where -- fmap = undefined -- -- Walk the data structure without introducing any additional data-parallelism. -- instance Traversable AList where -- traverse f al = -- case al of -- ANil -> pure ANil -- ASing x -> ASing <$> f x -------------------------------------------------------------------------------- -- Internal helpers: appendM :: ParFuture f p => AList a -> AList a -> p (AList a) appendM x y = return (append x y) monad-par-extras-0.3.3/Control/Monad/Par/State.hs0000644000000000000000000001026012170056302017674 0ustar0000000000000000{-# LANGUAGE ScopedTypeVariables, FlexibleInstances, MultiParamTypeClasses, UndecidableInstances, CPP #-} -- | This module provides a notion of (Splittable) State that is -- compatible with any Par monad. -- -- This module provides instances that make StateT-transformed -- monads into valid Par monads. module Control.Monad.Par.State ( SplittableState(..) ) where import Control.Monad import qualified Control.Monad.Par.Class as PC import Control.Monad.Trans import qualified Control.Monad.Trans.State.Strict as S import qualified Control.Monad.Trans.State.Lazy as SL --------------------------------------------------------------------------------- --- Make Par computations with state work. --- (TODO: move these instances to a different module.) -- | A type in `SplittableState` is meant to be added to a Par monad -- using StateT. It works like any other state except at `fork` -- points, where the runtime system splits the state using `splitState`. -- -- Common examples for applications of `SplittableState` would -- include (1) routing a splittable random number generator through -- a parallel computation, and (2) keeping a tree-index that locates -- the current computation within the binary tree of `fork`s. -- Also, it is possible to simply duplicate the state at all fork points, -- enabling "thread local" copies of the state. -- -- The limitation of this approach is that the splitting method is -- fixed, and the same at all `fork` points. class SplittableState a where splitState :: a -> (a,a) ---------------------------------------------------------------------------------------------------- -- Strict State: -- | Adding State to a `ParFuture` monad yields another `ParFuture` monad. instance (SplittableState s, PC.ParFuture fut p) => PC.ParFuture fut (S.StateT s p) where get = lift . PC.get spawn_ (task :: S.StateT s p ans) = do s <- S.get let (s1,s2) = splitState s S.put s2 -- Parent comp. gets one branch. lift$ PC.spawn_ $ S.evalStateT task s1 -- Child the other. -- | Likewise, adding State to a `ParIVar` monad yield s another `ParIVar` monad. instance (SplittableState s, PC.ParIVar iv p) => PC.ParIVar iv (S.StateT s p) where fork (task :: S.StateT s p ()) = do s <- S.get let (s1,s2) = splitState s S.put s2 lift$ PC.fork $ do S.runStateT task s1; return () new = lift PC.new put_ v x = lift$ PC.put_ v x newFull_ = lift . PC.newFull_ -- ParChan not released yet: #if 0 -- | Likewise, adding State to a `ParChan` monad yield s another `ParChan` monad. instance (SplittableState s, PC.ParChan snd rcv p) => PC.ParChan snd rcv (S.StateT s p) where newChan = lift PC.newChan recv r = lift $ PC.recv r send s x = lift $ PC.send s x #endif ---------------------------------------------------------------------------------------------------- -- Lazy State: -- -- | Adding State to a `ParFuture` monad yield s another `ParFuture` monad. instance (SplittableState s, PC.ParFuture fut p) => PC.ParFuture fut (SL.StateT s p) where get = lift . PC.get spawn_ (task :: SL.StateT s p ans) = do s <- SL.get let (s1,s2) = splitState s SL.put s2 -- Parent comp. gets one branch. lift$ PC.spawn_ $ SL.evalStateT task s1 -- Child the other. -- | Likewise, adding State to a `ParIVar` monad yield s another `ParIVar` monad. instance (SplittableState s, PC.ParIVar iv p) => PC.ParIVar iv (SL.StateT s p) where fork (task :: SL.StateT s p ()) = do s <- SL.get let (s1,s2) = splitState s SL.put s2 lift$ PC.fork $ do SL.runStateT task s1; return () new = lift PC.new put_ v x = lift$ PC.put_ v x newFull_ = lift . PC.newFull_ #if 0 -- | Likewise, adding State to a `ParChan` monad yield s another `ParChan` monad. instance (SplittableState s, PC.ParChan snd rcv p) => PC.ParChan snd rcv (SL.StateT s p) where newChan = lift PC.newChan recv r = lift $ PC.recv r send s x = lift $ PC.send s x #endif -- monad-par-extras-0.3.3/Control/Monad/Par/Pedigree.hs0000644000000000000000000000241712170056302020345 0ustar0000000000000000{-# LANGUAGE TypeSynonymInstances, CPP, FlexibleInstances, BangPatterns #-} -- | This module extends a Par monad with /pedigree/. That is, it -- allows a running computation to look up its position in the -- dynamic binary tree of `fork` calls ("ancestry"). module Control.Monad.Par.Pedigree ( pedigree, ParPedigreeT , unpack, runParPedigree ) where import Control.Monad.Par.Class import Control.Monad.Par.State import Control.Monad.Trans.State.Strict as S -- It's running slightly better with normal lists for parfib: #if 0 import Data.BitList type BList = BitList #else type BList = [Bool] unpack (Pedigree _ x) = x cons = (:) empty = [] #endif type ParPedigreeT p a = S.StateT Pedigree p a -- type Pedigree = BList -- -- | Trivial instance. -- instance SplittableState Pedigree where -- splitState bl = (cons False bl, cons True bl) data Pedigree = Pedigree { ivarCounter :: {-# UNPACK #-} !Int, treePath :: !BList } instance SplittableState Pedigree where splitState (Pedigree cnt bl) = (Pedigree cnt (cons False bl), Pedigree cnt (cons True bl)) pedigree :: ParFuture iv p => S.StateT Pedigree p Pedigree pedigree = S.get runParPedigree :: Monad p => ParPedigreeT p a -> p a runParPedigree m = S.evalStateT m (Pedigree 0 empty)