🚀 go-pugleaf

>Could you describe how Object Logo extends the language?  I'm curious just
>how it integrates object-oriented programming into Logo.  Does it come up
>with some sort of class abstraction, or does it deal directly with the
>objects themselves?

Here's an example of the use of objects from Object Logo's manual :

? make "scalingTurtle kindof turtle
? ask :scalingTurtle [to forward :steps]
> usual.forward :steps * :scale
> end
FORWARD defined.
? ask :scalingTurtle [to exist]
> usual.exist
> have "scale
> make "scale 1.0
> end
EXIST defined.
? make "fish oneof :scalingTurtle
? ask :fish [make "scale 2.0]

This demonstrates the creation of a subclass (scalingTurtle) from the
base class turtle.  The subclass inherits from its base class, and is
modified by the redefinitions of 'forward' and 'exist'.  At the end,
:fish is an insantiation of scalingTurtle.  It draws lines twice as
long as ordinary turtles in response to the same instructions.

Graham Mark
Los Alamos National Laboratory
(505)667-8147