Simple logger

Logger

(defpackage :debug
  (:use :common-lisp)
  (:export debug set-debug-output debug-call disable-logger enable-logger debug-type disabled with-disabled-loggers))
(in-package :debug)

(defclass logger ()
  ((types :initarg :types :initform nil :accessor types)
   (disabled :initarg :disabled :initform nil :accessor disabled)))
;All loggers start enabled
(defparameter *logger* (make-instance 'logger))

(defun logger-disabledp (type)
  (member type (disabled *logger*)))

(defun logger-enabledp (type)
  (not (logger-disabledp type)))

(defun enable-logger (type)
  (if (logger-disabledp type)
      (setf (disabled *logger*) (reverse (intersection (disabled *logger*) (list type) :test-not #'equalp)))))

(defun disable-logger (type)
  (pushnew type (disabled *logger*)))

(defmacro with-disabled-loggers (loggers &body body)
  (let ((listvar (gensym)))
    `(progn
       (dolist (,listvar ,loggers)
         (disable-logger ,listvar))
       (unwind-protect (progn ,@body)
         (dolist (,listvar ,loggers)
           (enable-logger ,listvar))))))

(defparameter *out* *standard-output*)
(defmacro debug-type (type s &rest rest)
  `(when (logger-enabledp ,type)
     (format *out* "DEBUG (~a): ~a~%" ,type (format nil ,s ,@rest))))

(defmacro debug (&rest rest)
  (etypecase (first rest)
    (string `(debug-type :default ,@rest))
    (symbol `(debug-type ,@rest))))


(defun set-debug-output (output)
  (setf *out* output))