go channel example

.gitignore

@@ -10,6 +10,7 @@ example-ssh/ssh-ed25519
 example-ssh/with-passwd
 
 example-expect/example-expect
+example-go-channel/example-go-channel
 example-gocui-active/example-gocui-active
 example-gocui-colorstrue/example-gocui-colorstrue
 example-gocui-dynamic/example-gocui-dynamic
@@ -25,3 +26,5 @@ example-ui-radiobutton/example-ui-radiobutton
 example-ui-splash/example-ui-splash
 example-ui-table/example-ui-table
 
+autobuild/autobuild
+example-flag/example-flag

example-go-channel/Makefile

@@ -0,0 +1,3 @@
+build:
+	GO111MODULE="off" go build -v -x
+	./go-channels

example-go-channel/main.go

@@ -0,0 +1,44 @@
+// https://www.digitalocean.com/community/tutorials/how-to-run-multiple-functions-concurrently-in-go
+// who came up with the idea of making community tutorials. that was a good idea!
+
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+func generateNumbers(total int, ch chan<- int, wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	for idx := 1; idx <= total; idx++ {
+		fmt.Printf("sending %d to channel\n", idx)
+		ch <- idx
+	}
+}
+
+func printInt(idx int, ch <-chan int, wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	for num := range ch {
+		fmt.Printf("%d: read %d from channel\n", idx, num)
+	}
+}
+
+func main() {
+	var wg sync.WaitGroup
+	numberChan := make(chan int)
+
+	for idx := 1; idx <= 2; idx++ {
+		wg.Add(1)
+		go printInt(idx, numberChan, &wg)
+	}
+
+	generateNumbers(10, numberChan, &wg)
+
+	close(numberChan)
+
+	fmt.Println("Waiting for goroutines to finish...")
+	wg.Wait()
+	fmt.Println("Done!")
+}