@nil@functional.cafe For silly example (not demonstrating pretty printing indentation levels and line width though) (uiop:define-package :fmt (:export escape eg)) (in-package :fmt) (defun +escape+ (stream arg &rest unused) (declare (ignore arg unused)) (format stream "~a[~dm" #\escape arg)) (defun eg () (format t "~/fmt:+escape+/~{~a~}~/fmt:+escape+/~%" 6 (mapcar 'code-char '(#x2631 #x20d5)) 0)) ;;☱⃕ Edit: Hmm I blocked that from working I guess. It's a blinking counterclockwise arrow lake.