"Robot registry" allowing access to built/known robots by index

[byorgey]

[NOTE: see also the comprehensive discussion in #506 .]

I was frustrated today when I forgot to bind the result of build to a variable name and it got me thinking about some related things again. What if every robot has a "registry" of robots that it has built, accessible by "child id"? In particular, I propose:

• adding a primitive child : int -> robot
• child n evaluates to the nth child built by the robot evaluating it
• when printing a robot value, print it in the form child n when possible (this will be most of the time)
• maybe there could also be friend : int -> robot which is a registry of other robots you know about
• evaluating some robot which is not a child will cause it to get added to the friend index, so it can be printed as friend k
• note friend and child indices will be specific to each robot; they will have nothing to do with internal (globally unique) robot ids, which will be completely hidden

Originally posted by @byorgey in #343 (comment)

A suggested recipe for a robot index is counter + logger.

[byorgey]

Note the discussion in #506 suggests that maybe we might not want to do this after all, since it doesn't completely solve the problem and we might prefer a more general solution.

[xsebek]

@byorgey huh? How so?

The latest comments there seem to point out the value of this child/friend approach in preventing instantaneous communication.

If I build ten robots I can just index them relative to this robot 1 to 10. Using withRobots does not give me parent child hierarchy AFAIK.

Personally I see value in both ways and would like to use them in challenges and scenarios - the functions presented here seem well suited to algorithmic problems in graphs an networks, where nodes know only their neighbours.

The more general approach seems a little godlike to me, bees or ants are not born with instant knowledge about the whole swarm. If you install antennas on them though…

[byorgey]

@xsebek oh, sorry, you're absolutely right! I was trying to summarize the related discussion on the other issue but didn't remember what we had discussed and re-read it too quickly.

[xsebek]

No worries, we have so many Issues that it’s almost impossible to remember all of them. 😄

I hope I didn’t discourage you from dusting off old Issues, I quite enjoy reading the summaries and updated plans. 😉

[byorgey]

I hope I didn’t discourage you from dusting off old Issues, I quite enjoy reading the summaries and updated plans.

No, not at all. Glad to hear it!

[TristanCacqueray]

I second what @xsebek said, swarm's issues are a great read on its own :)