monad-par-extras-0.3.3: Combinators and extra features for Par monads

Safe Haskell | Safe
Language | Haskell98

Control.Monad.Par.State

Contents

- Orphan instances

Description

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.

Synopsis

- class SplittableState a where

# Documentation

class SplittableState a where #

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.

Minimal complete definition

splitState

Methods

splitState :: a -> (a, a) #

# Orphan instances

(SplittableState s, ParFuture fut p) => ParFuture fut (StateT s p) # | Adding State to a `ParFuture` monad yield s another `ParFuture` monad.
Methods spawn :: NFData a => StateT s p a -> StateT s p (fut a) # spawn_ :: StateT s p a -> StateT s p (fut a) # get :: fut a -> StateT s p a # spawnP :: NFData a => a -> StateT s p (fut a) #
(SplittableState s, ParFuture fut p) => ParFuture fut (StateT s p) # | Adding State to a `ParFuture` monad yields another `ParFuture` monad.
Methods spawn :: NFData a => StateT s p a -> StateT s p (fut a) # spawn_ :: StateT s p a -> StateT s p (fut a) # get :: fut a -> StateT s p a # spawnP :: NFData a => a -> StateT s p (fut a) #
(SplittableState s, ParIVar iv p) => ParIVar iv (StateT s p) # | Likewise, adding State to a `ParIVar` monad yield s another `ParIVar` monad.
Methods fork :: StateT s p () -> StateT s p () # new :: StateT s p (iv a) # put :: NFData a => iv a -> a -> StateT s p () # put_ :: iv a -> a -> StateT s p () # newFull :: NFData a => a -> StateT s p (iv a) # newFull_ :: a -> StateT s p (iv a) #
(SplittableState s, ParIVar iv p) => ParIVar iv (StateT s p) # | Likewise, adding State to a `ParIVar` monad yield s another `ParIVar` monad.
Methods fork :: StateT s p () -> StateT s p () # new :: StateT s p (iv a) # put :: NFData a => iv a -> a -> StateT s p () # put_ :: iv a -> a -> StateT s p () # newFull :: NFData a => a -> StateT s p (iv a) # newFull_ :: a -> StateT s p (iv a) #