mirror of
https://github.com/golang/go
synced 2024-11-23 05:40:04 -07:00
73 lines
1.9 KiB
Go
73 lines
1.9 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);
|
|
if <-primes != 2 { panic 2 }
|
|
if <-primes != 3 { panic 3 }
|
|
if <-primes != 5 { panic 5 }
|
|
if <-primes != 7 { panic 7 }
|
|
if <-primes != 11 { panic 11 }
|
|
if <-primes != 13 { panic 13 }
|
|
if <-primes != 17 { panic 17 }
|
|
if <-primes != 19 { panic 19 }
|
|
if <-primes != 23 { panic 23 }
|
|
if <-primes != 29 { panic 29 }
|
|
if <-primes != 31 { panic 31 }
|
|
if <-primes != 37 { panic 37 }
|
|
if <-primes != 41 { panic 41 }
|
|
if <-primes != 43 { panic 43 }
|
|
if <-primes != 47 { panic 47 }
|
|
if <-primes != 53 { panic 53 }
|
|
if <-primes != 59 { panic 59 }
|
|
if <-primes != 61 { panic 61 }
|
|
if <-primes != 67 { panic 67 }
|
|
if <-primes != 71 { panic 71 }
|
|
if <-primes != 73 { panic 73 }
|
|
if <-primes != 79 { panic 79 }
|
|
if <-primes != 83 { panic 83 }
|
|
if <-primes != 89 { panic 89 }
|
|
if <-primes != 97 { panic 97 }
|
|
sys.exit(0);
|
|
}
|