生成器大家都晓得是怎么一回事，然而高阶生成器又是什么货色呢？明天小编就带着大家来一起理解一下吧……
先上代码：
function* numFrom(start: number) { while (true) yield start++}function* filter(nums: Generator<number>, prime: number) { for (const n of nums) if (n % prime !== 0) yield n}let cur = numFrom(2)for (let i = 0; i < 10; i++) { const prime = cur.next() if (!prime.done) { console.log(i, ':', prime.value) cur = filter(cur, prime.value) }}后果：
0 : 21 : 32 : 53 : 74 : 115 : 136 : 177 : 198 : 239 : 29其中函数 filter 传入一个生成器，返回一个新的生成器，咱们能够把它称为高阶生成器。
function* filter(nums: Generator<number>, prime: number) { for (const n of nums) if (n % prime !== 0) yield n}它的作用是过滤掉 nums: Generator<number> 生成的数中能被 prime 整除的数：
const gen = filter(numFrom(10), 3)for (let i = 0; i < 10; i++) { const n = gen.next() if (!n.done) console.log(n.value)}后果：
10111314161719202223能够看到，3 的倍数，12、15、18、21 曾经被过滤掉了。
如果咱们再把函数返回值作为参数传给 filter，就能过滤掉多个值了：
let gen = filter(numFrom(10), 3) // 从 10 开始，不能被 3 整除的数gen = filter(gen, 5) // 从 10 开始，不能被 3 和 5 整除的数...只有咱们一直把以后的生成器和产生的素数传入，咱们就可能实现过滤，相当于应用筛法生成素数。
let cur = numFrom(2)for (let i = 0; i < 10; i++) { const prime = cur.next() if (!prime.done) { console.log(i, ':', prime.value) cur = filter(cur, prime.value) // 产生新的生成器 }}numFrom(2) -> filter(2) -> filter(3) -> filter(5) -> filter(7) ...如果还不太革除，能够在控制台打印具体过程：
function* numFrom(start: number) { while (true) { console.log('\nnum yield', start) yield start++ }}let filterDeep = 0function* filter(nums: Generator<number>, prime: number) { const deep = filterDeep++ for (const n of nums) if (n % prime !== 0) { console.log(`filter yield[${deep}] ${n}`) yield n } else console.log(`filtered[${deep}] ${n} by ${prime}`)}let cur = numFrom(2)for (let i = 0; i < 10; i++) { const prime = cur.next() if (!prime.done) { console.log(i, ':', prime.value) cur = filter(cur, prime.value) }}后果：
num yield 20 : 2num yield 3filter yield[0] 31 : 3num yield 4filtered[0] 4 by 2num yield 5filter yield[0] 5filter yield[1] 52 : 5num yield 6filtered[0] 6 by 2num yield 7filter yield[0] 7filter yield[1] 7filter yield[2] 73 : 7num yield 8filtered[0] 8 by 2num yield 9filter yield[0] 9filtered[1] 9 by 3num yield 10filtered[0] 10 by 2num yield 11filter yield[0] 11filter yield[1] 11filter yield[2] 11filter yield[3] 114 : 11num yield 12filtered[0] 12 by 2num yield 13filter yield[0] 13filter yield[1] 13filter yield[2] 13filter yield[3] 13filter yield[4] 135 : 13num yield 14filtered[0] 14 by 2num yield 15filter yield[0] 15filtered[1] 15 by 3num yield 16filtered[0] 16 by 2num yield 17filter yield[0] 17filter yield[1] 17filter yield[2] 17filter yield[3] 17filter yield[4] 17filter yield[5] 176 : 17num yield 18filtered[0] 18 by 2num yield 19filter yield[0] 19filter yield[1] 19filter yield[2] 19filter yield[3] 19filter yield[4] 19filter yield[5] 19filter yield[6] 197 : 19num yield 20filtered[0] 20 by 2num yield 21filter yield[0] 21filtered[1] 21 by 3num yield 22filtered[0] 22 by 2num yield 23filter yield[0] 23filter yield[1] 23filter yield[2] 23filter yield[3] 23filter yield[4] 23filter yield[5] 23filter yield[6] 23filter yield[7] 238 : 23num yield 24filtered[0] 24 by 2num yield 25filter yield[0] 25filter yield[1] 25filtered[2] 25 by 5num yield 26filtered[0] 26 by 2num yield 27filter yield[0] 27filtered[1] 27 by 3num yield 28filtered[0] 28 by 2num yield 29filter yield[0] 29filter yield[1] 29filter yield[2] 29filter yield[3] 29filter yield[4] 29filter yield[5] 29filter yield[6] 29filter yield[7] 29filter yield[8] 299 : 29参考：
- 通道 - Kotlin 官网文档 https://book.kotlincn.net/text/channels.html