Golang设计模式——01工厂方法模式

package Factory_Method
type number struct {
  a float64
  b float64
}
type Operation interface {
  SetA(float64)
  SetB(float64)
  GetResult() float64
}
func (num *number) SetA(n float64) {
  num.a = n
}
func (num *number) SetB(n float64) {
  num.b = n
}
type addOperation struct {
  number
}
func (num *addOperation) GetResult() float64 {
  return num.a + num.b
}
type subOperation struct {
  number
}
func (num *subOperation) GetResult() float64 {
  return num.a - num.b
}
type mulOperation struct {
  number
}
func (num *mulOperation) GetResult() float64 {
  return num.a * num.b
}
type Factory interface {
  CreateOperation() Operation
}
type AddFactory struct {
}
func (a *AddFactory) CreateOperation() Operation {
  return &addOperation{}
}
type SubFactory struct {
}
func (s *SubFactory) CreateOperation() Operation {
  return &subOperation{}
}
type MulFactory struct {
}
func (m *MulFactory) CreateOperation() Operation {
  return &mulOperation{}
}

package Factory_Method
import (
  "fmt"
  "testing"
)
func TestCreateOperation(t *testing.T) {
  fac := &AddFactory{}
  opAdd := fac.CreateOperation()
  opAdd.SetA(1)
  opAdd.SetB(2)
  fmt.Println(opAdd.GetResult())
}