anchor.diff:                  ((syntax-string-quote-char-p c)
                    (line-put-property line i (1+ i) *string-color*)
                    (multiple-value-bind (j found-term-p)
  -                     (syntax-scan-string line (1+ i) nil)
  +                     (syntax-scan-string line (1+ i) nil c)
                      (setq i j)
                      (unless found-term-p
                        (setf (line-start-string-p line) t)
  
positive.code:   (let ((start-col 0))
      (cond (in-string-p
             (multiple-value-bind (i found-term-p)
                 (syntax-scan-string line 0 t)
               (cond (found-term-p
                      (setf (line-end-string-p line) t))
                     (t
  
negative.code:         (cond ((syntax-escape-char-p c)
                 (incf i))
                ((and (syntax-string-quote-char-p c)
                      (eql c (if (not multiple-lines-p)
                                 parallel-char
                                 (parallel-string-quote line))))
                 (line-put-property line
                                    start-col
                                    (1+ i)
  