Scope functions

Good overview about scopes and scope functions

Shadowing and Implicit Receivers

class Person(val name: String) {
    fun sayHello() = println("Hello!")
}

class Dog(val name: String) {
    fun bark() = println("Ruff!")
}

val person = Person("Julia")
val dog = Dog("Sparky")

with(person) {
    with(dog) {
        println(name) // Prints Sparky from the dog object
        bark()        // Calls bark() on the dog object
        sayHello()    // Calls sayHello() on the person object
    }
}

with(person) {
    with(dog) {
        println(this.name) // Prints Sparky
        this.bark()        // Calls bark() on the dog object
        this.sayHello()    // Compiler error - Unresolved reference: sayHello
    }
}

1. When using this, it will only refer to the exact implicit receiver in that scope.

2. When omitting this, the effective receiver is a combination of the implicit receivers, from the innermost to the outermost scope.