Kotlin property builder

builder.kt

package com.example.playground


class Builder {
    val setName: PropertiesSetter<String, Builder> = PropertiesSetter(this)
    
    val setAge: PropertiesSetter<Int, Builder> = PropertiesSetter(this)

    fun build(){
        setName.value
    }

    class PropertiesSetter<T, R>(private val r: R) {
        var value:T? = null
        operator fun invoke(t: T): R {
            value = t
            return r
        }
    }
}

val builder = Builder()
    .setName("haha")
    .setAge(15)
    .build()