Segmented unit info

[EphDoering]

This is just tracking knowledge on how segmented units are implemented and api access or lack thereof.

The entity that visually is the head of the segmented unit has type segmented-unit. The rest of the segments, including the tail, are entities of type segment.

The number (and type) of segments are available in the data stage but as far as I can tell are not available at runtime.

LuaEntity.neighbours doesn't work on them. commandable is nil for both the unit and segments.

However, the unit numbers are consecutive starting from the head going to the tail. A function to find entities of type segment or segmented-unit and correlating via unit_number should be sufficient for piecing them together if required.

Surface find functions

find_enemy_units and find_units, true to their descriptions, only find type unit. So they don't find these.
find_nearest_enemy does find them though.

[EphDoering]

My current opinion is that we don't need to request anything (besides territories which is a separate issue).

[ahicks92]

We should request anyway because it is a very reasonable request. I think that when it's "this really ahcky thing, or ask for an obviously missing API" it's fair for us to ask.

I'd also bet there's edge cases where the unit number thing doesn't hold true, because in practice that's not a function of demolishers, that's a function of entities being spawned one after another against a counter that happens to be monotonic.