ST +Control.Monad +base

module Control.Monad.ST
base Control.Monad.ST
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.
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) = _|_
module Control.Monad.ST.Strict
base Control.Monad.ST.Strict
The strict ST monad (re-export of Control.Monad.ST)
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.Instances
base Control.Monad.Instances
Functor and Monad instances for (->) r and Functor instances for (,) a and Either a.
fixST :: (a -> ST s a) -> ST s a
base Control.Monad.ST, base Control.Monad.ST.Lazy
Allow the result of a state transformer computation to be used (lazily) inside the computation. Note that if f is strict, fixST f = _|_.
lazyToStrictST :: ST s a -> ST s a
base Control.Monad.ST.Lazy
Convert a lazy ST computation into a strict one.
runST :: (forall s. ST s a) -> a
base Control.Monad.ST, base Control.Monad.ST.Lazy
Return the value computed by a state transformer computation. The forall ensures that the internal state used by the ST computation is inaccessible to the rest of the program.
unsafeInterleaveST :: ST s a -> ST s a
base Control.Monad.ST, base Control.Monad.ST.Lazy
unsafeIOToST :: IO a -> ST s a
base Control.Monad.ST, base Control.Monad.ST.Lazy
unsafeSTToIO :: ST s a -> IO a
base Control.Monad.ST