sczi

    >>> from packaging.version import Version
    >>> Version("1.2.3") > Version("1.2.2")
    True
    >>> Version("2.0") > Version("1.2.2")
    True

  def dec(f):
      def wraps():
          return f() + 2
      return wraps

  @dec
  def reload_me():
      return 1

  (use-package :serapeum)
  (defun adder (x)
    (flet ((inner (y) (/ x y)))
      #'inner))
  
  (defparameter *adders* (dict))
  
  (defun add (x y)
    (ensure (@ *adders* x) (adder x))
    (funcall (@ *adders* x) y))

  (add 3 6) ; => 1/2
  (add 3 9) ; => 1/3
  ;; change / to + in inner
  (add 4 9) ; => 13
  (add 3 10) ; => 3/10

  ctypes.pythonapi.PyFunction_SetClosure.argtypes = [ctypes.py_object, ctypes.py_object]
  ctypes.pythonapi.PyFunction_SetClosure(old, new.__closure__)