Strategy Pattern in Go

strategy_patten.go

package main

import (
	"fmt"
)

// Strategy is a strategy interface which should be implemented by
// the concrete strategies
type Strategy interface {
	execute(p *Route)
}

// Route is an object for context (in strategy pattern)
type Route struct {
	algo Strategy
}

// NewRoute is a constructor for Route
func NewRoute(s Strategy) *Route {
	return &Route{
		algo: s,
	}
}

// Set is a method to set strategy
func (r *Route) Set(s Strategy) {
	r.algo = s
}

// Execute is a method to run main strategy method
func (r *Route) Execute() {
	r.algo.execute(r)
}

// Road is a concrete strategy that should implement execute method
type Road struct{}

// execute is a method implementation
func (r *Road) execute(_ *Route) {
	fmt.Println("Executed by Road")
}

// PublicTransport is a concrete strategy that should implement execute method
type PublicTransport struct{}

// execute is a method implementation
func (r *PublicTransport) execute(_ *Route) {
	fmt.Println("Executed by PublicTransport")
}

// Walking is a concrete strategy that should implement execute method
type Walking struct{}

// execute is a method implementation
func (r *Walking) execute(_ *Route) {
	fmt.Println("Executed by Walking")
}

func main() {
	road := &Road{}

	route := NewRoute(road)
	route.Execute()

	publicTransport := &PublicTransport{}
	route.Set(publicTransport)
	route.Execute()

	walking := &Walking{}
	route.Set(walking)
	route.Execute()
}