Control.Monad.Trans.Crtn

definition of coroutine

Documentation

data Yld o x

yield command functor

Constructors

Yld o x

Instances

Functor (Yld o)

type GenT o = FreeT (Yld o)

Generator type is single-sided coroutine which only gives an output without getting any request.

yield :: Monad m => o -> GenT o m ()

primitive coroutine action yielding an output

newtype Awt a x

await command functor for consumer coroutine

Constructors

Awt (a -> x)

Instances

Functor (Awt g)

type CnsmT a = FreeT (Awt a)

Consumer type is a single-sided coroutine which only gets an input without producing output.

await :: Monad m => CnsmT a m a

primitive coroutine action awaiting an input

data Rqst req ans x

command functor of general bidirectional coroutine

Constructors

Rqst req (ans -> x)

Instances

Functor (Rqst req ans)

type CrtnT req ans = FreeT (Rqst req ans)

general symmetric bidirectional coroutine

request :: Monad m => req -> CrtnT req ans m ans

primitive request coroutine

type SrvT req ans m = ReaderT req (CrtnT ans req m)

Server type

type CliT req ans = CrtnT req ans

Coroutine type is regarded as a Client type which can be paired with Server type with opposite request and answer type.

data CrtnErr r

type for coroutine status after execution

Constructors

NoError

ServerFinished r

Other String

Instances

Show r => Show (CrtnErr r)

Error (CrtnErr r)

(<==|)

Arguments

:: Monad m

=> SrvT req ans m r'

server coroutine

-> CliT req ans m r

client coroutine

-> ErrorT (CrtnErr r') m (SrvT req ans m r', r)

connecting server and client in error monad

mapStateDown :: (Monad m, Functor f) => s -> FreeT f (StateT s m) a -> FreeT f m a

combine state and free monad with base state monad transformer with a base monad m to free monad with the base monad m Think this as fusing down the state monad