题目
实现一个LazyMan，可以按照以下方式调用：
LazyMan('Hank')
// 输出：
// Hi! This is Hank!
LazyMan('Hank').sleep(10).eat('dinner')
// 输出：
// Hi! This is Hank!
// 等待10秒
// Wake up after 10
// Eat dinner~
LazyMan('Hank').eat('dinner').eat('supper')
// 输出：
// Hi This is Hank!
// Eat dinner~
// Eat supper~
LazyMan('Hank').sleepFirst(5).eat('supper')
// 输出：
// 等待5秒
// Wake up after 5
// Hi This is Hank!
// Eat supper
// 以此类推。
题解
function LazyMan (name) {
function Man (name) {
this.todo = []
this.todo.push(() => {
console.log(`Hi! This is ${name}!`)
this._next()
})
setTimeout(() => {
this._next()
}, 0);
return this
}
Man.prototype._next = function () {
const fn = this.todo.shift()
fn && fn()
}
Man.prototype.sleep = function (second) {
this.todo.push(() => {
setTimeout(() => {
console.log(`Wake up after ${second}`)
this._next()
}, second * 1000)
})
return this
}
Man.prototype.sleepFirst = function (second) {
this.todo.unshift(() => {
setTimeout(() => {
console.log(`Wake up after ${second}`)
this._next()
}, second * 1000)
})
return this
}
Man.prototype.eat = function (which) {
this.todo.push(() => {
console.log(`Eat ${which}~`)
this._next()
})
return this
}
return new Man(name)
}
