Add Examples + More Verbose Logging

Signed-off-by: Sherif Abdel-Naby <sherifabdlnaby@gmail.com>

examples/scheduler/main.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"fmt"
+	"github.com/sherifabdlnaby/sched"
+	"log"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+)
+
+func main() {
+
+	job := func(id string) func() {
+		return func() {
+			log.Println(id + "\t Doing some work...")
+			time.Sleep(1 * time.Second)
+			log.Println(id + "\t Finished Work.")
+		}
+	}
+
+	cronTimer, err := sched.NewCron("* * * * *")
+	if err != nil {
+		panic(fmt.Sprintf("invalid cron expression: %s", err.Error()))
+	}
+
+	cronTimer5, err := sched.NewCron("*/5 * * * *")
+	if err != nil {
+		panic(fmt.Sprintf("invalid cron expression: %s", err.Error()))
+	}
+
+	fixedTimer30second, err := sched.NewFixed(30 * time.Second)
+	if err != nil {
+		panic(fmt.Sprintf("invalid interval: %s", err.Error()))
+	}
+
+	onceAfter10s, err := sched.NewOnce(10 * time.Second)
+	if err != nil {
+		panic(fmt.Sprintf("invalid delay: %s", err.Error()))
+	}
+
+	// Create Schedule
+	scheduler := sched.NewScheduler(sched.WithLogger(sched.DefaultLogger()),
+		sched.WithConsoleMetrics(1*time.Minute))
+
+	_ = scheduler.Add("cronEveryMinute", cronTimer, job("every-minute-cron"))
+	_ = scheduler.Add("cronEvery5Minute", cronTimer5, job("every-five-minute-cron"))
+	_ = scheduler.Add("fixedTimer30second", fixedTimer30second, job("fixedEvery30Second"))
+	_ = scheduler.Add("onceAfter10s", onceAfter10s, job("onceAfter10s"))
+
+	scheduler.StartAll()
+
+	// Listen to CTRL + C
+	signalChan := make(chan os.Signal, 1)
+	signal.Notify(signalChan, syscall.SIGTERM, syscall.SIGINT, syscall.SIGQUIT)
+	_ = <-signalChan
+
+	// Stop before shutting down.
+	scheduler.StopAll()
+
+	return
+}