[Etoys] simplifying basic category

[Yoshiki Ohshima]

  Subbu,

> The current slots/commands in basic category is part turtle geometry and part 
> cartesian geometry. I recast the viewer to include only turtle geometry 
> primitives in basic to make etoys easier for children who are yet to develop 
> intuitive understanding of co-ordinates. Why present two systems when one is 
> sufficient?

  Even if we follow this line of thought, you would still like to keep
"heading" in the basic category, yes?

  Ideally, we could have easier version(s) of position vector
representation in the basic category, but for various reasons (like
hiding scary-looking "@" operator), we sort of substitute the vector
representation of location with x and y.  This has some merit: the
first thing the end-user does after painting/instantiating an object
is to pick it up by a mouse and move.  If the viewer is opened, the x
and y values in the viewer will change and give good indication that
the viewer is actually a "view" on the object.  (And, by typing the
numbers, smart kids can tell that the relationship is bi-directional.)

  In future systems, the end-user should be able to reorganize the
categories for each object.  This way, a teacher can set up a nicer
material, for example.  You have a point, but but for now, I think
current affair is "ok".

  In future systems, various different notation/representation of
vectors should be really nice, too.  What kind of notation would be
good for children?

> I would have liked to make "pen down false/true" to "pen down/up" but I am yet 
> to figure out a simple way to get Boolean slots to support arbitrary 
> strings/symbols instead of just true/false values.

  Hmm, you might have to define a new DataType for it...

> throwing it open for discussions,

  Thank you!

-- Yoshiki