anchor.diff:  ; tré – Copyright (c) 2006–2015 Sven Michael Klose <pixel@hugbox.org>
   
  -(defvar *tagbody-replacements*)
  +(defvar *tagbody-replacements* nil)
   
   (defun init-compiler-macros ()
     (= *tagbody-replacements* nil))
   
  -(defvar *compiler-macro-expander* (define-expander 'compiler :pre  #'init-compiler-macros))
  +(defvar *compiler-macro-expander* (define-expander 'compiler :pre #'init-compiler-macros))
   
   (defmacro define-compiler-macro (name args &body x)
     (print-definition `(define-compiler-macro ,name ,args))
  
positive.code:   `(%%block ,@(@ [`(%= ,_. ,._.)]
                   (group args 2))))
  
  (defun make-? (body)
    (with (tests (group body 2)
           end   (car (last tests)))
      (unless body
  
negative.code:        ,@(? .end
              tests
              (+ (butlast tests) (list (. t end)))))))
  
  
  ;; TAGBODY
  