[Microbit-Python] How does GC work in micro:bit MicroPython?

[Larry Hastings]

On 10/12/2015 01:36 AM, Mark Shannon wrote:
> You'll need to make your button minder a MicroPython object anyway, so 
> it should be allocated on the MicroPython heap instead.

My plan, at least initially, was to keep the internal implementation 
details a secret from MicroPython.  The MP object stores a pointer to an 
opaque type (scheduler_t, etc) which is managed in my implementation.  
This makes debugging my classes on my Linux desktop feasible.

I wouldn't mind merging my objects irrevocably into MicroPython objects 
once everything is completely settled.


> OOI, would it be possible to add the additional functionality to the 
> pre-existing button object?

The thing is, there's a bit of logic in there that I don't know if we 
want to stain the button object with.  My button minder can handle 
watching three buttons for you: A, B, and "both".  Handling "both" means 
incurring a slight delay before recognizing a solo button press on A or 
B, because humans are slow.  Recognizing "both" is optional, and if you 
don't have it turned on there's no delay.

If we don't mind permanently incurring that delay, I could add a 
was_pressed() method to button_a and button_b, and add a separate 
button_both (button_ab?) object that behaved like a virtual both-buttons 
button.

FYI we could make it so the delay only affected was_pressed(), 
is_pressed() could still report in real-time.

In case you haven't looked at it, the rationale and API for my three 
objects is all up on the Bitbucket page.  That URL again:

    https://bitbucket.org/larry/microbit_game


> Perhaps a list of custom events objects would be more efficient.
> Whether custom object or tuple, it should be MicroPython objects all 
> the way down :)

A MicroPython list of custom event objects might be many things, but 
"more efficient" I sincerely doubt.  My current implementation has a 
packed C array of structs.  How could a MicroPython list of custom event 
objects possibly be more efficient, in any measurable dimension?

The Scheduler object really just contains that list of events.  So I 
wouldn't mind making it a subclass of the MP list, if that'd work... 
would it?  It really just needs a couple of extra methods on top of what 
list already provides.  Failing is-a, we're back to has-a, which is 
where we started.


//arry/

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