debug.lisp

;;; Debugging Helfer übernommen von Peter Norvig.
;;; Time-stamp: <2017-01-06 22:57:32 Martin>

(in-package :binoxxo-engine)

(defvar *dbg-ids* nil "Identifiers used by dbg")

(defun dbg (id format-string &rest args)
  "Print debugging info if (DEBUG ID) has been specified."
  (when (member id *dbg-ids*)
    (fresh-line *debug-io*)
    (apply #'format *debug-io* format-string args)))

(defun start-debug (&rest ids)
  "Start dbg output on the given ids."
  (setf *dbg-ids* (union ids *dbg-ids*)))

(defun undebug (&rest ids)
  "Stop dbg on the ids.  With no ids, stop dbg altogether."
  (setf *dbg-ids* (if (null ids) nil
                      (set-difference *dbg-ids* ids))))

(defun dbg-indent (id indent format-string &rest args)
  "Print indented debugging info if (DEBUG ID) has been specified."
  (when (member id *dbg-ids*)
    (fresh-line *debug-io*)
    (dotimes (i indent) (princ "  " *debug-io*))
    (apply #'format *debug-io* format-string args)))