/*
* Getters and setters in Kotlin
* getters are defined automatically for data classes
* setters are also defined automatically for var types 
* for data classes
*
* getters and setters are NOT defined for regualar classes
* but they can be written.
* 
* Note that  while the syntax is similar to that of Java
* public vars, it is NOT the same as setting is always done through
* get and set functions.   Usually they are just not seen.
*
* @author gtowell
* created: Oct 20. 2021
 */

data class Dxy(var x:Int, val y:Int)  {
}

fun doDataClass() {
    val dxy = Dxy(4,5)
    println(dxy)
    dxy.x = 8
    println(dxy)
    //dxy.y=10  // does not compile, this is a val so no setter
}

fun main() {
    doDataClass() 
    doClass()
    doExClass()

}


class Cxy(x:Int, y:Int) {
    var x:Int = x  // this is sort of like overriding x, but the compile treats it as you would want
        get() = field*3   // "field" needed in getters and setters to avoid infinite recursion. 
        //set(value) { field=value } // this is what the setter does anyway
    
    var y:Int = y
        set(value) {} // override the setter to do NOTHING
}


fun doClass() {
    val xy = Cxy(4,5)
    println(xy)
    println("Cxy xy.x = %d  xy.y=%d".format(xy.x, xy.y))
    xy.x = 8
    xy.y = 42
    println("Cxy xy.x = %d  xy.y=%d".format(xy.x, xy.y))
    //dxy.y=10  // does not compile, this is a val so no setter
}


class CCxy(var x:Int, val y:Int=1)
fun CCxy.x() = this.x*2 
fun CCxy.x(xx:Int):Unit { this.x = xx*2 }
var hidden:Int=0
var CCxy.z: Int // this property is NOT really in CCxy, but it looks like it is
    get()=hidden
    set(zz) { hidden = zz}


fun doExClass() {
    val xy = CCxy(4,5)
    println("CCxy x=%d y=%d z=%d".format(xy.x, xy.y, xy.z))
    xy.x = 8
    println("CCxy x=%d y=%d z=%d".format(xy.x, xy.y, xy.z))
    xy.z=9
    println("CCxy x=%d y=%d z=%d".format(xy.x, xy.y, xy.z))
}