I didn't try Hax but I hope someone who has can answer a question: does it support suspending current operation if user hits ESC key?

EDIT: I just looked at interrupt.c in the github repo: handles user interrupts. I trashed my Common Lisp harness because I had problems handling interrupts in a portable way. I did better with Racket. I am traveling on vacation without a computer, will try Hax when I get home.