continuation

continuation.go

func processLoop() {
    for {
            // process the next event.
    }
}

func (f *foo) a () {
    // check a bunch of assumptions.

    go func () {
        // b is a time consuming func, it returns a chan.
        future = b()
        <-future
        // put f.aa() in processing loop.
    }
}

func (f *foo) aa () {
    // check a bunch of assumptions again!!

    // continue the work of f.a().
}