reflect-sample.go

package main

import(
	"fmt"
	"reflect"
)

func main() {
	var hp, cp, wp, crp Printer
	hp = NewHelloPrinter()
	cp = NewCommaPrinter()
	wp = NewWorldPrinter()
	crp = NewCRPrinter()

	v := reflect.TypeOf(hp)
	v2 := reflect.TypeOf(new(HelloPrinter))
	fmt.Printf("%v\n", v)
	fmt.Printf("%v\n", v.Elem())
	fmt.Printf("%v\n", v == v2)
	fmt.Printf("%v\n", v.FieldByName)

	hp.Print()
	cp.Print()
	wp.Print()
	crp.Print()
}

type Printer interface {
	Print()
}

type rowPrinter struct {
	message string
}

func (rp *rowPrinter)Print() {
	fmt.Print(rp.message)
}

type HelloPrinter struct {
	rowPrinter
}
func NewHelloPrinter() Printer{
	hp := new(HelloPrinter)
	hp.message = "Hello"
	return hp
}

type CommaPrinter struct {
	rowPrinter
}
func NewCommaPrinter() Printer{
	cp := new(CommaPrinter)
	cp.message = ", "
	return cp
}

type WorldPrinter struct {
	rowPrinter
}
func NewWorldPrinter() Printer{
	wp := new(WorldPrinter)
	wp.message = "world"
	return wp
}

type CRPrinter struct {
	rowPrinter
}
func NewCRPrinter() Printer{
	crp := new(CRPrinter)
	crp.message = "\n"
	return crp
}