anchor.diff:          ,@body))))
   
   ;; Copyright (c) 2002-2006, Edward Marco Baringer
  +;; Copyright (c) 2011, Russ Tyndall, Acceleration.net
   ;; All rights reserved.
   ;;
   ;; Redistribution and use in source and binary forms, with or without
  
positive.code:    if you call the resultant function with no arguments, you get the
       collection so far
     if you call it with arguments the results of calling your function spec are
       collected "
    (alexandria:with-unique-names (col flet-args)
      `(let ((,col (make-collector)))
        (flet ((,name (&rest ,flet-args)
  
negative.code:    if you call the resultant function with no arguments, you get the
       collection so far
     if you call it with arguments the results of calling your function spec are
       collected
     (with-mapping-appender (app (l) (mapcar #'(lambda (x) (* 2 x)) l))
         (app '(1 2))
         (app '(2 3))
         (app '(3 4))
         (app)) => (2 4 4 6 6 8)
    "
    (alexandria:with-unique-names (col flet-args)
      `(let ((,col (make-appender)))
        (flet ((,name (&rest ,flet-args)
  