Functions

Send a message over a channel. Sending over a closed channel will raise a runtime exception.

Receive a message over a channel. Returns nil if the channel is closed

A dispatch statement starts the execution of an action as an independent concurrent thread of control within the same address space.

A select statement chooses which of a set of possible send or receive operations will proceed. It looks similar to a switch statement but with the cases all referring to communication operations.

var c1 Chan<String>()
var c2 Chan<String>()

// Each channel will receive a value after some amount of time, to simulate e.g. blocking RPC operations executing in concurrent operations.
dispatch {
    sleep(1)
    c1 <- "one"
}
dispatch {
    sleep(2)
    c2 <- "two"
}

// We’ll use select to await both of these values simultaneously, printing each one as it arrives.
for var i = 0; i < 2; i++ {
    _select {
        _case (msg1) { c1 in
            print("received", msg1)
        }
        _case (msg2) { c2 in
            print("received", msg2)
        }
    }
}

A case statement reads messages from a channel.

A default statement will run if the case channels are not ready.