今天用golang來作個 Lazy Evaluation.

可以參考一下說明:

http://en.wikipedia.org/wiki/Lazy_evaluation

// hello56
package main

import (
	"fmt"
)

var resume chan int

func integers() chan int {
	yield := make(chan int)
	count := 0
	go func() {
		for {
			yield <- count
			count++
		}
	}()
	return yield
}

func generateInteger() int {
	return <-resume
}

func main() {
	resume = integers()
	fmt.Println(generateInteger())
	fmt.Println(generateInteger())
	fmt.Println(generateInteger())
	fmt.Println(generateInteger())
}

執行結果:

./hello56 
0
1
2
3