|  | // run | 
|  |  | 
|  | // 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. | 
|  |  | 
|  | // Solve the 2,3,5 problem (print all numbers with 2, 3, or 5 as factor) using channels. | 
|  | // Test the solution, silently. | 
|  |  | 
|  | package main | 
|  |  | 
|  | type T chan uint64 | 
|  |  | 
|  | func M(f uint64) (in, out T) { | 
|  | in = make(T, 100) | 
|  | out = make(T, 100) | 
|  | go func(in, out T, f uint64) { | 
|  | for { | 
|  | out <- f*<-in | 
|  | } | 
|  | }(in, out, f) | 
|  | return in, out | 
|  | } | 
|  |  | 
|  |  | 
|  | func min(xs []uint64) uint64 { | 
|  | m := xs[0] | 
|  | for i := 1; i < len(xs); i++ { | 
|  | if xs[i] < m { | 
|  | m = xs[i] | 
|  | } | 
|  | } | 
|  | return m | 
|  | } | 
|  |  | 
|  |  | 
|  | func main() { | 
|  | F := []uint64{2, 3, 5} | 
|  | var n = len(F) | 
|  | OUT := []uint64{ | 
|  | 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 25, 27, 30, 32, 36, | 
|  | 40, 45, 48, 50, 54, 60, 64, 72, 75, 80, 81, 90, 96, 100, 108, 120, 125, | 
|  | 128, 135, 144, 150, 160, 162, 180, 192, 200, 216, 225, 240, 243, 250, | 
|  | 256, 270, 288, 300, 320, 324, 360, 375, 384, 400, 405, 432, 450, 480, | 
|  | 486, 500, 512, 540, 576, 600, 625, 640, 648, 675, 720, 729, 750, 768, | 
|  | 800, 810, 864, 900, 960, 972, 1000, 1024, 1080, 1125, 1152, 1200, 1215, | 
|  | 1250, 1280, 1296, 1350, 1440, 1458, 1500, 1536, 1600} | 
|  |  | 
|  | x := uint64(1) | 
|  | ins := make([]T, n) | 
|  | outs := make([]T, n) | 
|  | xs := make([]uint64, n) | 
|  | for i := 0; i < n; i++ { | 
|  | ins[i], outs[i] = M(F[i]) | 
|  | xs[i] = x | 
|  | } | 
|  |  | 
|  | for i := 0; i < len(OUT); i++ { | 
|  | for i := 0; i < n; i++ { | 
|  | ins[i] <- x | 
|  | } | 
|  |  | 
|  | for i := 0; i < n; i++ { | 
|  | if xs[i] == x { | 
|  | xs[i] = <-outs[i] | 
|  | } | 
|  | } | 
|  |  | 
|  | x = min(xs) | 
|  | if x != OUT[i] { | 
|  | println("bad: ", x, " should be ", OUT[i]) | 
|  | panic("235") | 
|  | } | 
|  | } | 
|  | } |