anchor.diff:                                    (princ .txt. !)
                                     (%format inf ..txt args))
           (character== txt. #\~)  (%format-directive inf .txt args)
  -        (progn
  -          (princ txt. !)
  -          (%format inf .txt args))))))
  +        (%format-char inf txt args)))))
   
   (defun format (str txt &rest args)
     (with-default-stream nstr str
       (with-temporary *print-automatic-newline?* nil
         (%format (make-format-info :stream nstr :text txt :args args) (string-list txt) args))))
  +
  +(defun neutralize-format-string (x)
  +  (list-string (mapcan [? (== _ #\~)
  +                          (list _ _)
  +                          (list _)]
  +                       (string-list x))))
  
positive.code: ;;;;; tré – Copyright (c) 2006–2008,2011–2013 Sven Michael Klose <pixel@copei.de>
  
  (defstruct format-info
    stream
  
negative.code: (defun %format-directive (inf txt args)
    (++! (format-info-processed-args inf))
    (case (char-upcase txt.) :test #'character==
      #\%  (%format-directive-eol inf .txt args)
      #\A  (%format-directive-placeholder inf .txt args)
      #\F  (%format-directive-force-output inf .txt args)
      #\~  (%format-char inf txt args)
      (%format-directive-tilde inf txt args)))
  
  (defun %format-char (inf txt args)
    (princ txt. (format-info-stream inf))
    (%format inf .txt args))
  
  (defun %format (inf txt args)
    (when txt
  