common lisp 的 访问器 SYMBOL-PLIST

symbol-plist.txt

语法
  symbol-plist symbol => plist
  (setf (symbol-plist symbol) new-plist)

参数和值
  symbol --- 一个 symbol
  plist, new-plist --- 一个属性列表

描述
  访问 symbol 的属性列表

代码
  * (setq sym (gensym))
  #:G605

  * (symbol-plist sym)
  NIL

  * (setf (get sym 'prop1) 'val1)
  VAL1

  * (symbol-plist sym)
  (PROP1 VAL1)

  * (setf (get sym 'prop2) 'val2)
  VAL2

  * (symbol-plist sym)
  (PROP2 VAL2 PROP1 VAL1)

  * (setf (symbol-plist sym) (list 'prop3 'val3))
  (PROP3 VAL3)

  *  (symbol-plist sym)
  (PROP3 VAL3)

  * (get sym 'PROP3)
  VAL3