// rune is an alias for int32 and is equivalent to
// int32 in all ways. It is
// used, by convention, to distinguish character
// values from integer values.

// int32的別名，幾乎在所有方面等同于int32
// 它用來區(qū)分字符值和整數(shù)值

type rune = int32

// 我們通常會使用rune類型 來對 ASCII碼與數(shù)字與字符之間的轉(zhuǎn)換
// 詳細(xì)轉(zhuǎn)換對應(yīng)關(guān)系 查ASCII碼表

package main

import (
	"fmt"
	"sync"
	"time"
)

type printDemo struct {
	ch    chan int        //傳遞打印數(shù)字
	count int             //計數(shù)
	ok    bool            //控制交替
	wg    *sync.WaitGroup //控制協(xié)程結(jié)束
}

func (p *printDemo) printNumber() {
	i := 1 //從1開始打印
	for {
		if p.ok {
			fmt.Println("print number is : ", i)
			p.ch <- i //傳遞給其他攜程
			p.ok = false
			i++
		}
		if i > p.count {
			return
		}

	}
}

func (p *printDemo) printABC() {
	time.Sleep(10 * time.Microsecond)
	for {
		ch, ok := <-p.ch
		if ok && !p.ok {
			//通過ASCII碼轉(zhuǎn)換成abc
			fmt.Printf("print abc is : %s\n", string(rune(ch+96)))
			p.ok = true
		}
		if ch == p.count {
			fmt.Println("over")
			p.wg.Done()
			return
		}
	}
}

func main() {
	p := printDemo{}
	p.wg = &sync.WaitGroup{}
	p.wg.Add(1)
	p.count = 26
	p.ch = make(chan int, p.count)
	p.ok = true
	go p.printNumber()
	go p.printABC()
	p.wg.Wait()
}