Initial commit. Just sketching some possible API ideas

cli.go

@@ -0,0 +1,60 @@
+package main
+
+func main() {
+	app := App{
+		Name:        "math",
+		Description: "a simple command line math utility",
+		Commands: []Command{
+			{
+				Name:        "add",
+				Description: "Add 2 and 2",
+				Action:      DoAdd},
+			{
+				Name:        "subtract",
+				Description: "Subtract 2 and 2",
+				Action:      DoSubtract},
+			{
+				Name:        "multiply",
+				Description: "Multiply 2 and 2",
+				Action:      DoMultiply},
+			{
+				Name:        "divide",
+				Description: "Divide 2 and 2",
+				Action:      DoDivide}}}
+
+	app.Run("add")
+}
+
+func DoAdd(name string) {
+  println("2+2=", 2+2)
+}
+
+func DoSubtract(name string) {
+  println("2-2=", 2-2)
+}
+
+func DoMultiply(name string) {
+  println("2*2=", 2*2)
+}
+
+func DoDivide(name string) {
+  println("2/2=", 2/2)
+}
+
+type App struct {
+	Name        string
+	Description string
+	Commands    []Command
+}
+
+type Command struct {
+	Name        string
+	Description string
+	Action      Action
+}
+
+type Action func(name string)
+
+func (a App) Run(command string) {
+	a.Commands[0].Action(a.Commands[0].Name)
+}