How to solve this strong dependency between those classes? - oop

Question

I have two classes A and B.
Class A has several properties. One of them are an instance of class B.
At some point in the main function I will define an instance a of A. I will need to do some computation on its property of type B.
This computation, however, needs another property of a.
The result is a.property3.computation(a.property1,someValue). I think it's ugly.
Here is some "pseudo-code" (in Kotlin but I am facing the same problem using other languages as well):
class B {
val property : Map<String,Int>
fun computation(val parameter1: Int, val parametre2: Double) : Int {
//doing some computation
return result
}
}
class A {
var property1 : Int
var property2 : Stirng
var property3 : B
}
fun main (){
val someValue = 0.4 //It's here to show the idea that the function `computation` needs also some other arguments that does not come from `A`'s propery
val a = A()
val result = a.property3.computation(a.property1,someValue) // here is the line that bothers me !
}

Answer 1

I think you should use Builder design pattern to remove computation function from B class like this:
class B {
val properties : MutableMap<String,Int> = HashMap()
fun setProperty(name: String, value: Int) {
this.properties[name] = value
}
}
class A {
var property1 : Int = 0
var property2 : String = ""
var property3 : B = B()
}
class Calculator(builder: Builder) {
private val property1 = builder.property1
private val someValue = builder.someValue
private val properties = builder.properties
companion object {
fun builder() = Builder()
}
fun computation() : Int {
//doing some computation
val result = property1 + someValue.toInt() + properties.getOrDefault("value", 0)
return result
}
class Builder {
var property1: Int = 0
var someValue: Double = 0.0;
var properties : MutableMap<String,Int> = HashMap()
fun property1(property1: Int): Builder {
this.property1 = property1
return this
}
fun someValue(someValue: Double): Builder {
this.someValue = someValue
return this
}
fun properties(properties : Map<String,Int>): Builder {
this.properties.putAll(properties);
return this
}
fun build(): Calculator {
return Calculator(this)
}
}
}
fun main (){
val someValue = 0.4 //It's here to show the idea that the function `computation` needs also some other arguments that does not come from `A`'s propery
val a = A()
a.property1 = 10
a.property3.setProperty("value", 20)
val result = Calculator.builder()
.properties(a.property3.properties)
.property1(a.property1)
.someValue(someValue)
.build()
.computation()
println(result)
}

Answer 2

May be you want this?
fun main (){
val someValue = 0.4
val a = A()
val result = with(a) {
property3.computation(property1,someValue)
}
}