[sugar] Pippy and Calculate

[Chris Ball]

Hi Yoshiki,

(I'm the Pippy author.)

   >   Imagine if Pippy has a button called "Print!", which would be
   > located right next to the "Run!"  button.  And, if "Print!" prints
   > out the results of running the program into the bottom pane, that
   > is pretty much all we need.  (For the record, the workspace in
   > Etoys has been there from day one for this purpose.)

This is a useful idea, thanks.  At the moment, Pippy doesn't keep any
variable/program state inbetween "Run!"s (each run is a new Python
interpreter), so there is no way to do "Ans*2"-style calculations.
It sounds like you want "Print!" to keep a single interpreter that
reinterprets the source pane at each click.

The first version of Pippy used a single Python interpreter that
executed the program source code in this way, without losing state,
but that makes it possible to write programs that will not run on a
fresh interpreter later (as they refer to state that was generated
as a result of code that no longer exists, or a previous run of the
code), so I decided against keeping that.

Oh!  We could have an "example" in Pippy that, when run, gives you a
Python interactive shell.  That should work well; it gives you the
mode you want (without requiring an extra button), and is useful in
any case.  I'll do that.

I don't think Python's evaluations are useful as a calculator to
a child, though.  You would have to explain this:

>>> 2+2
4
>>> 3/4
0

I would like to add a simple graphics screen to Pippy, but I don't
intend it to get many more features past that -- I'd like to keep
it at a simple introduction to input/output programming.

   > We have a real problem of shortage of man-power, so replacing
   > smaller activities that take more time to maintain and document
   > with more powerful ones is probably a good thing.

Just a note that Reinier Heeres is a volunteer, so isn't pulling OLPC
man-power away from any other projects.

Thanks!

- Chris.
-- 
Chris Ball   <cjb at laptop.org>