| // $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; |
| printf("%d\n", prime); |
| ch1 := new(chan int); |
| go Filter(ch, ch1, prime); |
| ch = ch1 |
| } |
| } |
| |
| func Main() { |
| Sieve() |
| } |