From f7141774a6ea414bdd4acacf96a461fd39648ba6 Mon Sep 17 00:00:00 2001
From: Billy Hinners <billyh@sunrunhome.com>
Date: Mon, 27 Feb 2017 12:39:25 -0500
Subject: [PATCH] Example of O-O in Go using embedded struct and interface

---
 carvalue.go | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 carvalue.go

diff --git a/carvalue.go b/carvalue.go
new file mode 100644
index 0000000..efb9e0a
--- /dev/null
+++ b/carvalue.go
@@ -0,0 +1,57 @@
+package main
+
+import (
+	"fmt"
+)
+
+type CarValue interface {
+	value() float64
+}
+
+type Car struct {
+	Make string
+	Year int
+}
+
+func (c *Car) value() float64 {
+	switch {
+	case c.Year >= 2000 && c.Year < 2010:
+		return 6500
+	case c.Year >= 2010 && c.Year < 2020:
+		return 9000
+	default:
+		return 3000
+	}
+}
+
+func NewCar(make string, year int) *Car {
+	return &Car{make, year}
+}
+
+type Tesla struct {
+	Car
+}
+
+func (t *Tesla) value() float64 {
+	switch {
+	case t.Year >= 2010 && t.Year < 2015:
+		return 18000
+	default:
+		return 24000
+	}
+}
+
+func NewTesla(year int) *Tesla {
+	return &Tesla{*NewCar("Tesla", year)}
+}
+
+func value(c CarValue) float64 {
+	return c.value()
+}
+
+func main() {
+	herbie := NewCar("Volkswagen", 1963)
+	model3 := NewTesla(2017)
+	fmt.Println("Herbie is worth", value(herbie))
+	fmt.Println("Model3 is worth", value(model3))
+}