Safe Haskell | Safe |
---|---|

Language | Haskell98 |

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

# 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.

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

## Instances

RandomGen g => SplittableState g # | Trivial instance. |

Defined in Control.Monad.Par.RNG splitState :: g -> (g, g) # |

# Orphan instances

(SplittableState s, ParFuture fut p) => ParFuture fut (StateT s p) # | Adding State to a |

(SplittableState s, ParFuture fut p) => ParFuture fut (StateT s p) # | Adding State to a |

(SplittableState s, ParIVar iv p) => ParIVar iv (StateT s p) # | Likewise, adding State to a |

(SplittableState s, ParIVar iv p) => ParIVar iv (StateT s p) # | Likewise, adding State to a |