other_module.rb

## Ruby has another way to do composition using modules and a concept
## called mixins.
## You simply create a module with functions that are common to classes
## and then include them in your class similar to using a require.

module Other

    def override()
        puts "OTHER override"
    end

    def implicit()
        puts "OTHER implicit()"
    end

    def Other.altered()
        puts "OTHER altered()"
    end
end

class Child
    include Other

    def override()
        puts "CHILD override"
    end

    def altered()
        puts "CHILD, BEFORE OTHER altered()"
        Other.altered()
        puts "CHILD, AFTER OTHER altered()"
    end
end

son = Child.new()

son.implicit()
son.override()
son.altered()