I quite like the concise state machine definitions used in Rodney Brooks' "A Robust Layered Control System for a Mobile Robot"[0]. The first element is the stat

I quite like the concise state machine definitions used in Rodney Brooks' "A Robust Layered Control System for a Mobile Robot"[0]. The first element is the state name, and whatever is returned is the next state. (defmodule avoid :inputs (force heading) :outputs (command) :instance-vars (resultforce) :states ((nil (event-dispatch (and force heading) plan)) (plan (setf resultforce (select-direction force heading)) go) (go (conditional-dispatch (significant-force-p resultforce 1.0) start nil)) (start (output command (follow-force resultforce)) nil))) [0] https://www.semanticscholar.org/paper/A-robust-layered-control-system-for-a-mobile-robot-Brooks/fb39b30187babe9bee4afb30b034b5f93b74859a https://www.semanticscholar.org/paper/A-robust-layered-contr...