anchor.diff:    (princ #\~ (format-info-stream inf))
     (%format inf txt args))
   
  -; TODO: Do it the Common Lisp way.
   (defun %format-directive (inf txt args)
     (++! (format-info-processed-args inf))
     (case (char-upcase txt.) :test #'character==
  
positive.code:                                   (princ .txt. !)
                                    (%format inf ..txt args))
          (character== txt. #\~)  (%format-directive inf .txt args)
          (%format-char inf txt args)))))
  
  (defun format (str txt &rest args)
    (with-default-stream nstr str
  
negative.code: ; tré – Copyright (c) 2006–2008,2011–2013,2015,2016 Sven Michael Klose <pixel@copei.de>
  
  (defstruct format-info
    stream
  