Channelを使ってのpipeline ref: http://qiita.com/items/0c61af9813b5039e21de

pipeline.go

package main

import "fmt"

func main() {
    queue := make(chan string)
    out   := make(chan int)
    foo := []string{"foo","bar","baz","spam","egg","ham"}
    var bar = map[string]int{
        "foo": 1,
        "bar": 2,
        "baz": 100,
    }

    var pipeline = func(in chan string, out chan int) {
        for {
            req, ok := <-in
            if !ok {
                break
            }
            if bar[req] != 0 {
                out <- bar[req]
            } else {
                fmt.Printf("pipeline --> %s:\n", req)
            }
        }
        close(out)
    }

    go func() {
        for i:=0; i<1000; i++ {
            queue <- foo[i%len(foo)]
        }
        close(queue)
    }()

    go pipeline(queue, out)

    for {
        req, ok := <-out
        if !ok {
            break
        }
        fmt.Printf("final --> %d\n", req)
    }
}