/**
* Gentle intro to Go structs
* structs are like Java classes, but without methods and without inheritance.
* (mostly).
*@author gtowell
* Created: Sep 12, 2021
 */

package main

import "fmt"

// create a basic struct.
// It holds 3 things.
type Strc struct {
	A int
	b string
	c float64
}

// this behaves much the same as the toString method in Java
func (item Strc) String() string {
	return fmt.Sprintf("Strcc A:%v  b:%v  c:%v", item.A, item.b, item.c);
}

type AStrc Strc

func main() {
	aa := AStrc{2,"sss", 3.1415}  // fill in order
	bb := Strc{b:"ggg", A:7, c:1.414} //fill by name
	// printing structs is easy.
	fmt.Printf("%v\n%+v\n", aa, bb)
	// q := aa.A * aa.c  // NOT ALLOWED -- if number are not the same type you must cast
	qi := aa.A * int(bb.c)
	qf := float64(aa.A) * bb.c 
	fmt.Printf("int:%d  float:%f\n", qi, qf)

	a2 := aa
	fmt.Printf("A2:%v, aa==a2:%t\n", a2, aa==a2)
	a2.c = 55.4
	fmt.Printf("A2:%v, aa==a2:%t\n", a2, aa==a2)
	
	//a3 := Strc{a2.A, a2.b, a2.c}
	//fmt.Printf("A3:%v, aa==a3:%t\n", a3, a2==a3) //this line will not compile

	b2 := AStrc{a2.A, a2.b, a2.c}
	fmt.Printf("b2:%v\n", b2)
	//fmt.Printf("b2:%v, aa==b2:%t\n", b2, aa==b2) // compiler flags this out to not allow compare of mismatched types. .. Why not allow?
}