Hello, On Wed, 24 Jun 2015 09:19:55 +0200 Antoine Pitrou <solipsis@pitrou.net> wrote:
On Tue, 23 Jun 2015 23:25:00 +0300 Paul Sokolovsky <pmiscml@gmail.com> wrote:
Well, that's one of examples of that "desktop" thinking ;-). Consider for example that 2^32 microseconds is just over an hour, so expressing everything in microseconds would require arbitrary-precision integers, which may be just the same kind of burden for an embedded system as floats.
I'd like to suggest micropython first acquire the ability to handle 64-bit numbers (or something close to that, e.g. 60-bit, if it likes to use tags for typing), if it wants to become appropriate for precise datetime computations.
MicroPython has such support. Long integers can be implemented either as variable-size arbitrary-precisions integers or and C long long type. But that doesn't change the fact that 64-bit values still overflow, or that we don't want to force need for any kind of long integer on any particular implementation. We don't even want to mask the fact that fixed-size (time) counters overflow - for various reasons, including the fact that we want to follow Python's tradition of being nice teaching/learning language, and learning embedded programming means learning to deal with timer, etc. overflows. So, the question is not how to "appropriate for precise datetime computations" - MicroPython inherits that ability by being a Python, but how to scale into the opposite direction, how to integrate into stdlib "realtime" time handling, which is simple, fast (getting timing value itself is low-overhead) and modular-arithmetic by its nature.
That should be less of a heavy requirement than arbitrary-precision ints.
Regards
Antoine.
-- Best regards, Paul mailto:pmiscml@gmail.com