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// 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)
}
}
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