anchor.diff:    :after  (lambda (%argtoo)
               (frob-trace "GOT ARGTOO AFTER ~s" %argtoo))
     )
  -))             
  +))
   
   #+test (quux 12)
   ;; ^FIXME: *trace-output* shows order of eval: :BEFORE, :AFTER, :DURING
  
positive.code:    :type function)
    ;; NB: no portable 'environment' type.
    ;; 'env' slot may only be useful for debugging
    (env)
    (name #:unnamed
          :type function-name))
  
  
negative.code:             (,%form
               (eval (function-lambda-expression
                      ;; FIXME: ^ THIS might not always "work out"
                      (or (macro-function ,%name ,%env)
                          (error "No macro function defined for ~S"
                                 ,%name))))))
  
         (register-advise ,%name ,%env ,%form)
             
  