Control.Concurrent.CHP.Channels.Ends

Channels in CHP must be used via their ends. It is generally these ends that you pass around to processes that want to communicate on the channel -- thus it is possible to see from the type ('Chanin'\/'Chanout') whether the process will use it for reading or writing. The channel-ends are named from the perspective of processes: a Chanin is a channel-end that a process may input values from, whereas a Chanout is a channel-end that a process may output values to.

Documentation

data Chanin a

A reading channel-end type.

See reader to obtain one, and ReadableChannel for how to use one.

Eq instance added in version 1.1.1

Instances

ReadableChannel Chanin

Channel Chanin Chanout

Channel Chanin (Shared Chanout)

Eq (Chanin a)

Poisonable (Chanin a)

Channel (Shared Chanin) Chanout

Channel (Shared Chanin) (Shared Chanout)

data Chanout a

A writing channel-end type.

See writer to obtain one, and WritableChannel for how to use one.

Eq instance added in version 1.1.1

Instances

WriteableChannel Chanout

Channel Chanin Chanout

Channel Chanin (Shared Chanout)

Eq (Chanout a)

Poisonable (Chanout a)

Channel (Shared Chanin) Chanout

Channel (Shared Chanin) (Shared Chanout)

data Shared c a

A wrapper (usually around a channel-end) indicating that the inner item is shared. Use the claim function to use this type.

Instances

Channel Chanin (Shared Chanout)

Channel BroadcastChanin (Shared BroadcastChanout)

Channel (Shared Chanin) Chanout

Channel (Shared Chanin) (Shared Chanout)

reader :: Chan r w a -> r a

Gets the reading end of a channel from its Chan type.

writer :: Chan r w a -> w a

Gets the writing end of a channel from its Chan type.

readers :: [Chan r w a] -> [r a]

Gets all the reading ends of a list of channels. A shorthand for map reader.

writers :: [Chan r w a] -> [w a]

Gets all the writing ends of a list of channels. A shorthand for map writer.

claim :: Shared c a -> (c a -> CHP b) -> CHP b

Claims the given channel-end, executes the given block, then releases the channel-end and returns the output value. If poison or an IO exception is thrown inside the block, the channel is released and the poison/exception re-thrown.