Re: Bug/Patch view.el

[Glenn Morris <rgm@gnu.org>]

Eventually I settled on this version, which reduces the number of
operations in the loop.

(defun view-search-no-match-lines (times regexp)
  "Search for the TIMESth occurrence of a line with no match for REGEXP.
If such a line is found, return non-nil and set the match-data to that line.
If TIMES is negative, search backwards."
  (let ((step 1)
        (noerror 'move))
    (when (< times 0)
      (setq times (- times)
            step -1
            noerror t))
    ;; Note that we do not check the current line.
    (while (and (> times 0)
                (zerop (forward-line step)))
      ;; Move only to handle eob in the forward case: on last line,
      ;; (forward-line 1) returns 0 before the end of line.
      (or (re-search-forward regexp (line-end-position) noerror)
          (setq times (1- times)))))
  (when (zerop times)
    (forward-line 0)
    (looking-at ".*")))