anchor.diff:    `(call-with-input-file ,path ,element-type ,if-does-not-exist ,external-format (lambda (,streamvar) ,@body)))
   
   
  +(defmacro with-io-syntax (&body body)
  +  `(let ((*package* (load-time-value (or (find-package "COM.INFORMATIMAGO.COMMON-LISP.CESARUM.FILE.IO")
  +                                         (make-package "COM.INFORMATIMAGO.COMMON-LISP.CESARUM.FILE.IO"
  +                                                       :use '()))))
  +         (*print-array* t)
  +         (*print-base* 10.)
  +         (*print-case* :upcase)
  +         (*print-circle* t) ;*
  +         (*print-escape* t)
  +         (*print-gensym* t)
  +         (*print-length* nil)
  +         (*print-level* nil)
  +         (*print-lines* nil)
  +         (*print-miser-width* nil)
  +         (*print-pretty* nil)
  +         (*print-radix* t)
  +         (*print-readably* t)
  +         (*print-right-margin* nil)
  +         (*read-base* 10.)
  +         (*read-default-float-format* 'double-float) ;*
  +         (*read-eval* nil) ;*
  +         (*read-suppress* nil))
  +     ,@body))
  +
   (defun sexp-file-contents (path &key (if-does-not-exist :error)
                                     (external-format :default))
     "
  
positive.code:             (push dst-file copied-files)))))))
  
  
  
  
  (defun call-with-input-file (path element-type if-does-not-exist external-format thunk)
    (let ((if-does-not-exist-action (if (member if-does-not-exist '(:error :create nil))
                                        if-does-not-exist
  
negative.code: RETURN:             The first SEXP of the file at PATH, or the value
                      of IF-DOES-NOT-EXIST when not :ERROR or :CREATE
                      and the file doesn't exist.
                      The second value is t, unless the file is empty.
  "
    (with-input-file (in path 'character if-does-not-exist external-format)
      (with-io-syntax
        (let ((contents (read in nil in)))
          (if (eq contents in)
              (values nil nil)
              (values contents t))))))
  
  
  (defun (setf sexp-file-contents) (new-contents path
                                    &key (if-does-not-exist :create)
                                      (if-exists :supersede)
                                      (external-format :default))
    "
  DO:     Writes the NEW-CONTENTS SEXP readably into the file at PATH.  By default,
          that file is created or superseded; this can be changed with
          the keyword IF-DOES-NOT-EXIST or IF-EXISTS.
  RETURN: The NEW-CONTENTS, or if-exists or if-does-not-exist in case of error.
  "
    (with-open-file (out path :direction :output
                              :if-does-not-exist if-does-not-exist
                              :if-exists if-exists
                              :external-format external-format)
      (if (and (streamp out) (not (or (eq out if-exists)  (eq out if-does-not-exist))))
          (with-io-syntax
              (write new-contents :stream out))
          out)))
  
  
  (defun sexp-list-file-contents (path &key (if-does-not-exist :error)
                                         (external-format :default))
    "
  IF-DOES-NOT-EXIST:  Can be :error, :create, nil, or another value that
                      is returned instead of the content of the file if
                      it doesn't exist.
  
  RETURN:             All the SEXPs of the file at PATH gathered in a
                      list, or the value of IF-DOES-NOT-EXIST when not
                      :ERROR or :CREATE and the file doesn't exist.
  "
    (with-input-file (in path 'character if-does-not-exist external-format)
      (with-io-syntax
        (loop
          :for form = (read in nil in)
          :until (eq form in)
          :collect form))))
  
  (defun (setf sexp-list-file-contents) (new-contents path
                                         &key (if-does-not-exist :create)
                                           (if-exists :supersede)
                                           (external-format :default))
    "
  NEW-CONTENTS:   A list of sexps.
  
  DO:             Writes the NEW-CONTENTS SEXPs readably into the file
                  at PATH.  By default, that file is created or
                  superseded; this can be changed with the keyword
                  IF-DOES-NOT-EXIST or IF-EXISTS.
  
  RETURN:         The NEW-CONTENTS, or if-exists or if-does-not-exist in
                  case of error.
  "
    (with-open-file (out path :direction :output
                         :if-does-not-exist if-does-not-exist
                         :if-exists if-exists
                         :external-format external-format)
      (if (and (streamp out) (not (or (eq out if-exists)  (eq out if-does-not-exist))))
          (with-io-syntax
            (loop
              :for form :in new-contents
              :do (write form :stream out
  