lib/time: un-export the variable Now

The original idea of providing Now is to mock the current time in
testing Scheduler.
Since this variable can be overridden by other packages, it is not safe
to export it, hence we un-export it here so it can be used internal only.

lib/time/scheduler.go

@@ -123,7 +123,7 @@ type Scheduler struct {
 func NewScheduler(schedule string) (sch *Scheduler, err error) {
 	var (
 		logp = `NewScheduler`
-		now  = Now().UTC()
+		now  = timeNow().UTC()
 	)
 
 	sch, err = newScheduler(schedule, now)
@@ -574,7 +574,7 @@ func (sch *Scheduler) run() {
 			// receiving the event.
 			var now = sch.next
 
-			sch.calcNext(Now().UTC())
+			sch.calcNext(timeNow().UTC())
 			ticker.Reset(sch.nextDuration)
 
 			select {

lib/time/scheduler_example_test.go

@@ -1,25 +1,23 @@
-package time_test
+package time
 
 import (
 	"fmt"
 	"log"
 	"time"
-
-	libtime "github.com/shuLhan/share/lib/time"
 )
 
 func ExampleScheduler_Next() {
-	// Override Now for making this example works.
-	libtime.Now = func() time.Time {
+	// Override timeNow to make this example works.
+	timeNow = func() time.Time {
 		return time.Date(2013, time.January, 20, 14, 26, 59, 0, time.UTC)
 	}
 
 	var (
-		sch *libtime.Scheduler
+		sch *Scheduler
 		err error
 	)
 
-	sch, err = libtime.NewScheduler(`minutely`)
+	sch, err = NewScheduler(`minutely`)
 	if err != nil {
 		log.Fatal(err)
 	}

lib/time/scheduler_test.go

@@ -20,7 +20,7 @@ func TestNewScheduler(t *testing.T) {
 		err  error
 	)
 
-	Now = func() (now time.Time) {
+	timeNow = func() (now time.Time) {
 		switch step {
 		case 0:
 			step++

lib/time/time.go

@@ -10,10 +10,10 @@ import (
 	"time"
 )
 
-// Now returns the current local time.
-// Unlike standard library, this is a variable that can be override to mock
-// the current time during testing.
-var Now = func() time.Time {
+// timeNow returns the current local time.
+// This is a variable that can be override to mock the current time during
+// testing.
+var timeNow = func() time.Time {
 	return time.Now()
 }