chain_of_responsibility.go

// Package chain_of_responsibility is an example of the Chain Of Responsibility Pattern.
package chain_of_responsibility

// Handler provides a handler interface.
type Handler interface {
	SendRequest(message int) string
}

// ConcreteHandlerA implements handler "A".
type ConcreteHandlerA struct {
	next Handler
}

// SendRequest implementation.
func (h *ConcreteHandlerA) SendRequest(message int) (result string) {
	if message == 1 {
		result = "Im handler 1"
	} else if h.next != nil {
		result = h.next.SendRequest(message)
	}
	return
}

// ConcreteHandlerB implements handler "B".
type ConcreteHandlerB struct {
	next Handler
}

// SendRequest implementation.
func (h *ConcreteHandlerB) SendRequest(message int) (result string) {
	if message == 2 {
		result = "Im handler 2"
	} else if h.next != nil {
		result = h.next.SendRequest(message)
	}
	return
}

// ConcreteHandlerC implements handler "C".
type ConcreteHandlerC struct {
	next Handler
}

// SendRequest implementation.
func (h *ConcreteHandlerC) SendRequest(message int) (result string) {
	if message == 3 {
		result = "Im handler 3"
	} else if h.next != nil {
		result = h.next.SendRequest(message)
	}
	return
}