more examples

example-go-channel/Makefile

@@ -4,3 +4,8 @@ build:
 
 simple:
 	GO111MODULE="off" go build -v -x -o ~/go/bin/simple-worker simple-worker.go
+	simple-worker
+
+return-vals:
+	GO111MODULE="off" go build -v -x -o ~/go/bin/return-vals return-vals.go
+	return-vals

example-go-channel/main.go

@@ -14,6 +14,7 @@ func generateNumbers(total int, ch chan<- int, wg *sync.WaitGroup) {
 	for idx := 1; idx <= total; idx++ {
 		fmt.Printf("START sending %d to channel\n", idx)
 		ch <- idx
+		// res, err := (<-r)()
 		fmt.Printf("END sending %d to channel\n", idx)
 	}
 	wg.Wait()

example-go-channel/return-vals.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"log"
+)
+
+var res int
+var err error
+
+type FuncResult func() (int, error)
+/*
+
+func funcWithError(f chan FuncResult) {
+	f <- (func() (int, error) { return 123, nil })
+}
+
+func main() {
+	r := make(chan FuncResult)
+	//...
+}
+*/
+
+
+func funcWithError(f chan FuncResult) {
+	f <- (func() (int, error) { return 123, nil })
+}
+
+func blah() (int, error) {
+	log.Println("Ran blah()")
+	return 21, nil
+}
+
+func main() {
+	// r := make(chan func() (int, error))
+	r := make(chan FuncResult)
+	go funcWithError(r)
+	res, err = (<-r)()
+	if err == nil {
+		log.Printf("My result is %d again!", res)
+	} else {
+		log.Printf("The func returned an error: %s", err)
+	}
+
+	/*
+	r <= blah
+	if err == nil {
+		log.Printf("My result is %d again!", res)
+	} else {
+		log.Printf("The func returned an error: %s", err)
+	}
+	*/
+}