mirror of
https://github.com/golang/go
synced 2024-11-23 03:50:03 -07:00
983f06bdb6
* 1. all statements and declarations are terminated by semicolons * 2. semicolons can be omitted at top level. * 3. semicolons can be omitted before and after the closing ) or } * on a list of statements or declarations. /home/rsc/bin/addsemi and then diff+tweak. R=r,gri OCL=16620 CL=16643
52 lines
1.3 KiB
Go
52 lines
1.3 KiB
Go
// $G $D/$F.go && $L $F.$A && ./$A.out
|
|
|
|
// 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.
|
|
|
|
// This version generates up to 100 and checks the results.
|
|
// With a channel, of course.
|
|
|
|
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(primes *chan<- int) {
|
|
ch := new(chan int); // Create a new channel.
|
|
go Generate(ch); // Start Generate() as a subprocess.
|
|
for {
|
|
prime := <-ch;
|
|
primes <- prime;
|
|
ch1 := new(chan int);
|
|
go Filter(ch, ch1, prime);
|
|
ch = ch1
|
|
}
|
|
}
|
|
|
|
func main() {
|
|
primes := new(chan int);
|
|
go Sieve(primes);
|
|
a := []int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97};
|
|
for i := 0; i < len(a); i++ {
|
|
if <-primes != a[i] { panic(a[i])}
|
|
}
|
|
sys.exit(0);
|
|
}
|