Io_Language

 Object ancestor := method (

     prototype := self proto

     if (prototype != Obejct,

         writeln ("Slots of ",

                  prototype type,

                  "\n------------------"

         )

         prototype slotNames foreach (slotName,

                                      writeln (slotName)

         )

         writeln prototype ancestors

     )

 )

 

 unless := method (

     (

             call sender doMessage (

                     call message argAt(0)

             )

     )

     ifFalse (

             call sender doMessage (

                     call message argAt(1)

             )

     )

     ifTrue (

             call sender doMessage (

                     call message argAt(2)

             )

     )

 )

　Animals.io

    Object ancestors := method (

        prototype := self proto

        if (prototype != Object,

            writeln ("Slots of ", 

                prototype type,

                "\n----------------"

            )

            prototype slotNames foreach (

                slotName, 

                writeln (sloteName)

            )

            writeln prototype ancestors

        )

    )

    

    Animal := Object clone

    Animal speak := method (

        "ambiguous animal noise" println

    )

    Duck := Animal clone

    Duck speak := method (

        "quack" println

    )

    Duck walk := method (

        "waddle" println

    )

    disco := Duck clone

    disco ancestors