mirror of
https://github.com/golang/go
synced 2024-11-12 05:30:21 -07:00
27c0eb8431
powser1.go has not been tested - waiting for compiler to catch up R=ken OCL=15415 CL=15415
43 lines
996 B
Go
43 lines
996 B
Go
// $G $F.go && $L $F.$A # don't run it - goes forever
|
|
|
|
// 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
|
|
|
|
// Send the sequence 2, 3, 4, ... to channel 'ch'.
|
|
func Generate(ch *chan<- int) {
|
|
for i := 2; ; i++ {
|
|
ch <- i // Send 'i' to channel 'ch'.
|
|
}
|
|
}
|
|
|
|
// Copy the values from channel 'in' to channel 'out',
|
|
// removing those divisible by 'prime'.
|
|
func Filter(in *<-chan int, out *chan<- int, prime int) {
|
|
for {
|
|
i := <-in // Receive value of new variable 'i' from 'in'.
|
|
if i % prime != 0 {
|
|
out <- i // Send 'i' to channel 'out'.
|
|
}
|
|
}
|
|
}
|
|
|
|
// The prime sieve: Daisy-chain Filter processes together.
|
|
func Sieve() {
|
|
ch := new(chan int); // Create a new channel.
|
|
go Generate(ch); // Start Generate() as a subprocess.
|
|
for {
|
|
prime := <-ch;
|
|
print(prime, "\n");
|
|
ch1 := new(chan int);
|
|
go Filter(ch, ch1, prime);
|
|
ch = ch1
|
|
}
|
|
}
|
|
|
|
func main() {
|
|
Sieve()
|
|
}
|