add command design pattern

Author: Yeminting

command/command.go

@@ -0,0 +1,51 @@
+package command
+
+import "fmt"
+
+type ICommand interface {
+	Excute()
+	Cancel()
+}
+
+type Revicer struct {
+}
+
+func (r *Revicer) Do() {
+	fmt.Println("revicer do something")
+}
+
+func (r *Revicer) UnDo() {
+	fmt.Println("revicer undo something")
+}
+
+type CreateCommand struct {
+	revicer *Revicer
+}
+
+func (c *CreateCommand) SerRevicer(s *Revicer) {
+	c.revicer = s
+}
+
+func (c *CreateCommand) Excute() {
+	c.revicer.Do()
+}
+
+func (c *CreateCommand) Cancel() {
+	c.revicer.UnDo()
+}
+
+type Invoker struct {
+	command ICommand
+}
+
+func (i *Invoker) SetCmd(c ICommand) {
+	i.command = c
+}
+
+func (i *Invoker) ExcuteCmd() {
+	i.command.Excute()
+}
+
+func (i *Invoker) CancelCmd() {
+	i.command.Cancel()
+}

command/command_test.go

@@ -0,0 +1,17 @@
+package command
+
+import "testing"
+
+func TestCommand(t *testing.T) {
+	r := new(Revicer)
+	c := new(CreateCommand)
+	c.SerRevicer(r)
+	invoker := Invoker{}
+	invoker.SetCmd(c)
+
+	invoker.ExcuteCmd()
+	invoker.CancelCmd()
+	//out
+	//revicer do something
+	//revicer undo something
+}