ST +Control.Monad

This library provides support for strict state threads, as described in the PLDI '94 paper by John Launchbury and Simon Peyton Jones Lazy Functional State Threads.

module Control.Monad.ST.Strict

base Control.Monad.ST.Strict

The strict ST monad (re-export of Control.Monad.ST)

data ST s a

base Control.Monad.ST.Lazy

The lazy state-transformer monad. A computation of type ST s a transforms an internal state indexed by s, and returns a value of type a. The s parameter is either * an unstantiated type variable (inside invocations of runST), or * RealWorld (inside invocations of stToIO). It serves to keep the internal states of different invocations of runST separate from each other and from invocations of stToIO. The >>= and >> operations are not strict in the state. For example, > runST (writeSTRef _|_ v >>= readSTRef _|_ >> return 2) = 2

data ST s a

base Control.Monad.ST

The strict state-transformer monad. A computation of type ST s a transforms an internal state indexed by s, and returns a value of type a. The s parameter is either * an uninstantiated type variable (inside invocations of runST), or * RealWorld (inside invocations of Control.Monad.ST.stToIO). It serves to keep the internal states of different invocations of runST separate from each other and from invocations of Control.Monad.ST.stToIO. The >>= and >> operations are strict in the state (though not in values stored in the state). For example, > runST (writeSTRef _|_ v >>= f) = _|_

strictToLazyST :: ST s a -> ST s a

base Control.Monad.ST.Lazy

Convert a strict ST computation into a lazy one. The strict state thread passed to strictToLazyST is not performed until the result of the lazy state thread it returns is demanded.

stToIO :: ST RealWorld a -> IO a

base Control.Monad.ST.Lazy

A monad transformer embedding lazy state transformers in the IO monad. The RealWorld parameter indicates that the internal state used by the ST computation is a special one supplied by the IO monad, and thus distinct from those used by invocations of runST.

stToIO :: ST RealWorld a -> IO a

base Control.Monad.ST

A monad transformer embedding strict state transformers in the IO monad. The RealWorld parameter indicates that the internal state used by the ST computation is a special one supplied by the IO monad, and thus distinct from those used by invocations of runST.

module Control.Monad.RWS.Strict

mtl Control.Monad.RWS.Strict

Strict RWS monad. Inspired by the paper Functional Programming with Overloading and Higher-Order Polymorphism, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

module Control.Monad.State

mtl Control.Monad.State

State monads. This module is inspired by the paper Functional Programming with Overloading and Higher-Order Polymorphism, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

module Control.Monad.State.Strict

mtl Control.Monad.State.Strict

Strict state monads. This module is inspired by the paper Functional Programming with Overloading and Higher-Order Polymorphism, Mark P Jones (http://web.cecs.pdx.edu/~mpj/) Advanced School of Functional Programming, 1995.

module Control.Monad.STM

stm Control.Monad.STM

Software Transactional Memory: a modular composable concurrency abstraction. See * Composable memory transactions, by Tim Harris, Simon Marlow, Simon Peyton Jones, and Maurice Herlihy, in /ACM Conference on Principles and Practice of Parallel Programming/ 2005. http://research.microsoft.com/Users/simonpj/papers/stm/index.htm This module only defines the STM monad; you probably want to import Control.Concurrent.STM (which exports Control.Monad.STM).

module Control.Monad.Trans.RWS.Strict

transformers Control.Monad.Trans.RWS.Strict

A monad transformer that combines ReaderT, WriterT and StateT. This version is strict; for a lazy version, see Control.Monad.Trans.RWS.Lazy, which has the same interface.

module Control.Monad.Trans.State

transformers Control.Monad.Trans.State

State monads, passing an updatable state through a computation. Some computations may not require the full power of state transformers: * For a read-only state, see Control.Monad.Trans.Reader. * To accumulate a value without using it on the way, see Control.Monad.Trans.Writer. This version is lazy; for a strict version, see Control.Monad.Trans.State.Strict, which has the same interface.

module Control.Monad.Trans.State.Strict

transformers Control.Monad.Trans.State.Strict

Strict state monads, passing an updatable state through a computation. See below for examples. In this version, sequencing of computations is strict. For a lazy version, see Control.Monad.Trans.State.Lazy, which has the same interface. Some computations may not require the full power of state transformers: * For a read-only state, see Control.Monad.Trans.Reader. * To accumulate a value without using it on the way, see Control.Monad.Trans.Writer.

module Control.Monad.Trans.Writer.Strict

transformers Control.Monad.Trans.Writer.Strict

The strict WriterT monad transformer, which adds collection of outputs (such as a count or string output) to a given monad. This version builds its output strictly; for a lazy version, see Control.Monad.Trans.Writer.Lazy, which has the same interface. This monad transformer provides only limited access to the output during the computation. For more general access, use Control.Monad.Trans.State instead.

module Control.Monad.Writer.Strict

mtl Control.Monad.Writer.Strict

Strict writer monads. Inspired by the paper Functional Programming with Overloading and Higher-Order Polymorphism, Mark P Jones (http://web.cecs.pdx.edu/~mpj/pubs/springschool.html) Advanced School of Functional Programming, 1995.