New version of systemTime that returns an Int representing microseconds

[alvaroc1]

Resolves #2359

Tests pass and have used the new function successfully (i hacked the previous version for the test), but will require an update of base.

Base refers to systemTime.impl which is a built-in, but i'm not sure how that connects to systemTime.impl.v3, i'm guessing something else needs to be wired (?)

[atacratic]

Hooray! ☺️

But looks like impl just multiplies by a million, and can't actually work out the time to precision better than a second?

[alvaroc1]

Hooray! ☺️

But looks like impl just multiplies by a million, and can't actually work out the time to precision better than a second?

My very limited understanding is that getPOSIXTime produces something equivalent to a Real (?) or a Float representing seconds including fractions of a second. Multiplying it by a million turns it to microseconds and something later turns it into Int.

My animation code depends on it having microsecond resolution, and seems to work fine at least when rendering 30 fps, which makes me think the code is correct. But i can't claim to understand all the details :/

[atacratic]

Oh magic, OK, nice one, sorry for misunderstanding!

Cheers for doing this 👍

[pchiusano]

Great! Left a couple comments though.

[pchiusano]

Also anytime you update the builtins, run stack exec transcripts after. CI checks that transcript output hasn't changed, and the set of builtins affects some transcript output.

[pchiusano]

Great!