mixins.ooc

Printable: interface {

    // this one has to be implemented
    toString: func -> String

    // this one has a default impl.
    println: func {
        toString() println()
    }

    // this one has a default impl too
    prettyPrint: func {
        "Charly says: " print()
        println()
    }

}

Number: class implements Printable {

    value: Int
    init: func (=value) {}

    // we're required to implement this one, so let's implementt it
    toString: func -> String { value toString() }

    // but we override this one
    prettyPrintln: func {
        "<< %s >>!" printfln(toString())
    }

}

n := Number new(42)
n toString() println()
n println()
n prettyPrintln()