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cpu.lisp

(defmacro defenum (name (&rest keys))
  "Define a function named %NAME, that takes an argument KEY. If KEYS are
scalar values, the corresponding index in KEYS is return. Otherwise, the
associated value is returned."
  `(defun ,(intern (format nil "%~A" (string-upcase name))) (key)
     (let ((enum ',(loop for i = 0 then (1+ i)
                      for key in keys
                      collect (typecase key
                                (list key)
                                (t (cons key i))))))
       (rest (assoc key enum)))))

(defmacro defenum (name (&rest keys))
  "Define a function named %NAME, that takes an argument KEY. If KEYS are
scalar values, the corresponding index in KEYS is return. Otherwise, the
associated value is returned."
  (let* ((enum-sym (intern (format nil "*~A-ENUM*" (string-upcase name)))))
    `(progn
       (defvar ,enum-sym ',keys)
       (defun ,(intern (format nil "%~A" (string-upcase name))) (key)
         (position key ,enum-sym ,@(when (typep (car keys) 'list)
                                         `(:key #'first)))))))


(defmacro defenum (name (&rest keys))
  "Define a function named %NAME, that takes an argument KEY. If KEYS are
scalar values, the corresponding index in KEYS is return. Otherwise, the
associated value is returned."
  `(defun ,(intern (format nil "%~A" (string-upcase name))) (key)
     (let ((enum ',keys))
       (position key enum ,@(when (typep (car keys) 'list) `(:key #'first))))))

;; Example Usage
(defenum status-bit (:carry :zero :interrupt :decimal
                     :break :unused :overflow :negative))

(defenum status-bit ((:carry 1) (:zero 2) (:interrupt 4) (:decimal 8)
                     (:break 16) (:unused 32) (:overflow 64) (:negative 128)))