Non working code panics on runtime.

asyncfetchtimeout.go

package main

import (
	"fmt"
	"net"
	"net/http"
	"time"
)

var urls = []string{
	"http://pulsoconf.co/",
	"http://golang.org/",
	"http://matt.aimonetti.net/",
}

var timeout = time.Duration(5e7)

type HttpResponse struct {
	url      string
	response *http.Response
	err      error
}

func dialTimeout(network, addr string) (net.Conn, error) {
	return net.DialTimeout(network, addr, timeout)
}

func asyncHttpGets(urls []string) <-chan *HttpResponse {
	ch := make(chan *HttpResponse, len(urls)) // buffered
	transport := http.Transport{
		Dial: dialTimeout,
	}
	client := http.Client{
		Transport: &transport,
	}
	for _, url := range urls {
		go func(url string) {
			fmt.Printf("Fetching %s \n", url)
			resp, err := client.Get(url)
			if err != nil {
				ch <- &HttpResponse{url, nil, err}
			}
			defer resp.Body.Close()
			ch <- &HttpResponse{url, resp, err}
		}(url)
	}
	return ch

}

func main() {
	ch := asyncHttpGets(urls)
	for _ = range urls {
		x := <-ch
		fmt.Printf("%s status: %s\n", x.url, x.response.Status)
	}
}