DFHack
suggestion: tool to reorder machine list by descending z-level
It's well-known that a pump stack constructed top down is more efficient than one constructed bottom up, due to the fact that machines are processed in reverse order by ID. A tool to reorder the machine list in order to put the machines into this "optimal" order would likely be viewed as useful.
Note that this will probably require renumbering individual machines, which would require remapping everything that stores a reference to a machine by ID; we'd have to identify all of these for this to be a viable tool.
This would actually be reordering buildings, since "machines" are what DF uses to link buildings+axes+gears together (and thus a pump stack would be considered a single machine).
Worth remembering that a "stack" isn't necessarily always vertical. I've got a mist generator where most of the pump stack is vertical, but the ones at the top and bottom are offset by one pump horizontally. Yet, I built them in the correct order so that the water goes from one end to the other in one tick. So the logic should check where the pump's input/output tiles are and see if it overlaps the input/output tiles of other pumps to determine which machine should be orderer earlier/later. Something that also needs to be considered is if more than two pumps share the same overlapping input/output tiles.
