anchor.diff:                                   (with-module-storage (,modulevar)
                                      ,@body)))))
                            body))))
  -         (set-timer-function ',name ,handler :type ,type :docstring ,documentation)))))
  +         (set-timer-function ',name ,handler :type ,type :docstring ,documentation
  +                             ,@(when module-name
  +                                 `(:launcher #'(lambda (thread function)
  +                                                 (module-launcher ,module-name thread function)))))))))
  
positive.code:   ""
    (let ((handler (time-handler identifier)))
      (when handler
        (unless (= 0 (length (active-timers handler)))
          (v:warn :timer "Stopping ~d active timers of ~a due to removal." (length (active-timers handler)) identifier)
          (loop for thread in (active-timers handler)
                do (destroy-thread thread)))
        (remhash identifier *timer-map*))))
  
  (defun set-timer-function (identifier handler-function &key (type :multiple) (arguments () a-p) docstring)
    ""
    (assert (symbolp identifier) () "IDENTIFIER has to be a symbol.")
    (when (time-handler identifier)
      (v:debug :timer "Redefining handler ~a" identifier)
      (when (active-timers (time-handler identifier))
        (v:warn :timer "Redefining running timer ~a" identifier)))
    (unless a-p
      (setf arguments (cdr (function-arguments handler-function))))
    (setf (time-handler identifier)
          (make-instance 'time-handler 
                         :identifier identifier :handler-function handler-function
                         :timer-type type :docstring docstring)))
  
  (defgeneric apropos-time-handler (handler)
  
negative.code:    (%timer-type :initarg :timer-type :initform :multiple :accessor timer-type)
     (%arguments :initarg :arguments :initform () :accessor arguments)
     (%handler-function :initarg :handler-function :initform (error "Handler function required.") :accessor handler-function)
     (%launcher-function :initarg :launcher-function :initform #'simple-launcher :accessor launcher-function)
     (%schedulings :initarg :schedulings :initform () :accessor schedulings)
     (%handler-lock :initarg :handler-lock :initform (make-lock) :accessor handler-lock)
     (%docstring :initarg :docstring :initform NIL :accessor docstring))
    (:documentation ""))
  