future-blog-post-12

client3.go

func main() {
    a := 10
    f := future.New(func() (interface{}, error) {
        return doSomethingThatTakesAWhile(a)
    }).Then(func(v interface{}) (interface{}, error) {
        return doAnotherThing(v.(int))
    })

    // this will wait for a second to complete
    // and will return nil for both val and err
    // and timeout will be true
    val, timeout, err := f.GetUntil(1 * time.Second)
    fmt.Println(val, timeout, err)

    // this will wait for val and err to have values
    val, err = f.Get()
    fmt.Println(val, err)

    // this will error out on the first step, so we
    // don’t do the long-running thing next
    g := future.New(func() (interface{}, error) {
        return doAnError(a)
    }).Then(func(v interface{}) (interface{}, error) {
        return doSomethingThatTakesAWhile(v.(int))
    })

    val2, timeout2, err2 := g.GetUntil(1 * time.Second)
    fmt.Println(val2, timeout2, err2)
}