Inheritance

warning

At this moment, Drift does not implement inheritance.

class Parent {
    fun test { ... }
}

class ChildA extend Parent {
    override fun test { ... }
}
// or
class ChildB : Parent {
    override fun test { ... }
}

Another important feature of Object-Oriented-Programing is inheritance. Classes can inherit from others. The inheriting Class is called subclass, and the inherited one is called parent or superclass. A class can inherit from once superclass.

Subclasses inherit of their superclass members like methods, attributes and subscripts. They can override their definition using the override keyword as prefix.

Accessing Superclass Members

warning

At this moment, Drift does not implement superclass accessing.

class Parent : +Subscriptable {
    let age: Int = 56

    subscript (i: Int) : Int {
        ...
    }

    fun test { ... }
}

class Child : Parent {
    override let age: Int = $super.age / 2
    
    override subscript (x, y) : Int {
        return $super[x * y]
    }

    override fun test {
        ...
        $super.test()
    }
}

Disable Overriding On Member

warning

At this moment, Drift does not implement Override Preventing

class A {
    final let a: Int = 1
}

It is possible to prevent any override of a Class member by using the final keyword.