Make it easier to partially fill wells in the macro language

[EvanKirshenbaum]

Looking at the way OSU is doing macros, it's pretty clear that it's time to expose more of the internal volume control in the macro language.

What they really want to be able to do is to say simply

wC : prepare to dispense(3 drops of reagent "A");

What this should do is to call

   w.required = liq.volume
   w.ensure_content(liq.volume, liq.reagent)

In addition, it would be useful to expose the following attributes on well:

• fill level (max_volume): the maximum volume to fill to.
• refill level (min_volume): the minimum volume (after a dispense) to trigger a refill.
• required: the volume you expect to need to dispense. This is decremented every time a drop is dispensed (or fluid is otherwise transferred out).

Migrated from internal repository. Originally created by @EvanKirshenbaum on Feb 28, 2023 at 12:33 PM PST. Closed on Feb 28, 2023 at 1:54 PM PST.

[EvanKirshenbaum]

This issue was referenced by the following commit before migration:

• 30a7e1377793884026ee234e890ba2932c3aca99 by @EvanKirshenbaum on Feb 28, 2023 at 1:44 PM PST

[EvanKirshenbaum]

Added

• w : prepare to dispense
• w : prepare to dispense(2 drops)
• w : prepare to dispense(reagent "R")
• w : prepare to dispense(10 drops of reagent "R")
• w's fill level = 10uL
• w's refill level = 1uL
• w's requirement = 100 drops

I changed required to requirement because w's required sounded weird.

While doing this, I changed the definition of Well.fill_to from

    @property
    def fill_to(self) -> Volume:
        def default_fill_line() -> Volume:
            if self.required is None:
                return self.capacity
            return min(self.capacity, self.required)
        return self.volume_from_spec(self._fill_to, default_fill_line)

to

    @property
    def fill_to(self) -> Volume:
        def default_fill_line() -> Volume:
            if self.required is None:
                return self.max_fill
            return min(self.max_fill, self.required+self.min_fill)
        return self.volume_from_spec(self._fill_to, default_fill_line)

Two changes:

1. Use max_fill rather than capacity
2. Make sure that there will be min_fill left after dispensing when required isn't None.

   Migrated from internal repository. Originally created by @EvanKirshenbaum on Feb 28, 2023 at 1:54 PM PST.