implemented template pattern

behavioral/template_p/templateP.go

@@ -0,0 +1,41 @@
+package template_p
+
+import (
+	"fmt"
+	
+)
+
+type Greeter interface {
+	message() string
+}
+
+type GreeterTemplate interface {
+	first() string
+	third() string
+	greet(Greeter) string
+}
+
+type PrincesGreeterTmpl struct {}
+func (p PrincesGreeterTmpl) first() string {
+	return "Welcome"
+}
+func (p PrincesGreeterTmpl) third() string {
+	return "to our palace!"
+}
+func (p PrincesGreeterTmpl) greet(g Greeter) string {
+	return fmt.Sprintf("%s, %s %s", p.first(), g.message(), p.third())
+}
+
+type PrincesGreeter struct {
+	name string
+}
+func (p *PrincesGreeter) message() string {
+	return fmt.Sprintf("your magesty princes %s", p.name)
+}
+
+func Demo()  {
+	prGreeter := &PrincesGreeter{"Diana"}
+	tmpl := PrincesGreeterTmpl{}
+
+	fmt.Println(tmpl.greet(prGreeter))
+}