From 92522f33aee6022aca08a7f02dab5ace10ad7ee4 Mon Sep 17 00:00:00 2001
From: Jian Han <jianhan@mail.com>
Date: Wed, 2 May 2018 20:23:43 +1000
Subject: [PATCH] v2 handle error

---
 concurrency/iterator_error_handling/main.go | 44 +++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/concurrency/iterator_error_handling/main.go b/concurrency/iterator_error_handling/main.go
index 621717a..b33ba21 100644
--- a/concurrency/iterator_error_handling/main.go
+++ b/concurrency/iterator_error_handling/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"net/http"
 	"time"
 
 	"github.com/davecgh/go-spew/spew"
@@ -34,6 +35,8 @@ func concurrentFetch(urls []string) <-chan *FetchResult {
 }
 
 func main() {
+	v2()
+	return
 	// mock the urls
 	urls := []string{
 		"test1",
@@ -63,3 +66,44 @@ func main() {
 	// }
 	fmt.Println("All my things are done")
 }
+
+type Result struct {
+	Error    error
+	Response *http.Response
+}
+
+func v2() {
+	checkStatus := func(done <-chan interface{}, urls ...string) <-chan Result {
+		results := make(chan Result)
+		go func() {
+			defer close(results)
+			for _, url := range urls {
+				var result Result
+				resp, err := http.Get(url)
+				result = Result{Error: err, Response: resp}
+				select {
+
+				case <-done:
+					return
+				case results <- result:
+				}
+			}
+		}()
+		return results
+	}
+	done := make(chan interface{})
+	errCount := 0
+	urls := []string{"a", "https://www.google.com", "b", "c", "d"}
+	for result := range checkStatus(done, urls...) {
+		if result.Error != nil {
+			fmt.Printf("error: %v\n", result.Error)
+			errCount++
+			if errCount >= 3 {
+				fmt.Println("Too many errors, breaking!")
+				break
+			}
+			continue
+		}
+		fmt.Printf("Response: %v\n", result.Response.Status)
+	}
+}