mirror of
https://github.com/golang/go
synced 2024-09-28 22:24:29 -06:00
2ccd20a646
Fixes #1742. I hope. Also this picks up an update to go_tutorial.html that should already have happened. R=brainman, rsc, peterGo CC=golang-dev https://golang.org/cl/4452050
52 lines
901 B
Go
52 lines
901 B
Go
// Copyright 2009 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
import "fmt"
|
|
|
|
// Send the sequence 2, 3, 4, ... to returned channel
|
|
func generate() chan int {
|
|
ch := make(chan int)
|
|
go func(){
|
|
for i := 2; ; i++ {
|
|
ch <- i
|
|
}
|
|
}()
|
|
return ch
|
|
}
|
|
|
|
// Filter out input values divisible by 'prime', send rest to returned channel
|
|
func filter(in chan int, prime int) chan int {
|
|
out := make(chan int)
|
|
go func() {
|
|
for {
|
|
if i := <-in; i % prime != 0 {
|
|
out <- i
|
|
}
|
|
}
|
|
}()
|
|
return out
|
|
}
|
|
|
|
func sieve() chan int {
|
|
out := make(chan int)
|
|
go func() {
|
|
ch := generate()
|
|
for {
|
|
prime := <-ch
|
|
out <- prime
|
|
ch = filter(ch, prime)
|
|
}
|
|
}()
|
|
return out
|
|
}
|
|
|
|
func main() {
|
|
primes := sieve()
|
|
for i := 0; i < 100; i++ { // Print the first hundred primes.
|
|
fmt.Println(<-primes)
|
|
}
|
|
}
|