example-runtime.go

type Model struct{}
type Cmd struct {}
type Msg struct {}
type Flags struct{}

// func initialize(flags Flags) (Model, Cmd)
// func update(msg Msg, model Model) (Model, Cmd)

func programLoop() {
	var mutex sync.Mutex
	var flags Flags
	var messages = make(chan Msg, 0)
	globalState, cmd := initialize(flags)
	go execAndEmitMsg(cmd, messages)

	for msg := range messages {
		mutex.Lock()
		newState, cmd := update(msg, globalState)
		globalState = newState
		mutex.Unlock()
		go execAndEmitMsg(cmd, messages)
	}
}

//
//
//

func execAndEmitMsg(cmd Cmd, messages chan<- Msg) {
	switch cmd.kind {
	case "Http.get":
		resp, err := fetchText(cmd.data)
		if err != nil {
			messages <- Msg{name: cmd.msg, Err: err}
			return
		}
		messages <- Msg{name: cmd.msg, Ok: resp}
	}
}

// func fetchText(url string) (string, error)