future-blog-post-4

client.go

 package main

 import (
	 "time"
	 "fmt"
	 "future"
 )

 func doSomethingThatTakesAWhile(i int) (int, error) {
 	// what this does isn’t that important for the example
 	// but it’s really important in your program
 	time.Sleep(2*time.Second)
 	return i * 2, nil
 }

 func main() {
 	a := 10
 	f := future.New(func() (interface{}, error) {
 		return doSomethingThatTakesAWhile(a)
 	})
 
	 // this will take about 2 seconds to complete
 	val, err := f.Get()
 	fmt.Println(val, err)
 
	 // this will complete immediately
 	val, err = f.Get()
 	fmt.Println(val, err)
 }