Return to compare-w.el CVS log

Up to [CSRG BSD Unix] / 43BSD / contrib / emacs / lisp

Annotation of 43BSD/contrib/emacs/lisp/compare-w.el, revision 1.1

1.1     ! root        1: ;; Compare text between windows for Emacs.
        !             2: ;; Copyright (C) 1985 Richard M. Stallman.
        !             3: 
        !             4: ;; This file is part of GNU Emacs.
        !             5: 
        !             6: ;; GNU Emacs is distributed in the hope that it will be useful,
        !             7: ;; but WITHOUT ANY WARRANTY.  No author or distributor
        !             8: ;; accepts responsibility to anyone for the consequences of using it
        !             9: ;; or for whether it serves any particular purpose or works at all,
        !            10: ;; unless he says so in writing.  Refer to the GNU Emacs General Public
        !            11: ;; License for full details.
        !            12: 
        !            13: ;; Everyone is granted permission to copy, modify and redistribute
        !            14: ;; GNU Emacs, but only under the conditions described in the
        !            15: ;; GNU Emacs General Public License.   A copy of this license is
        !            16: ;; supposed to have been given to you along with GNU Emacs so you
        !            17: ;; can know your rights and responsibilities.  It should be in a
        !            18: ;; file named COPYING.  Among other things, the copyright notice
        !            19: ;; and this notice must be preserved on all copies.
        !            20: 
        !            21: 
        !            22: (defun compare-windows ()
        !            23:   "Compare text in current window with text in next window.
        !            24: Compares the text starting at point in each window,
        !            25: moving over text in each one as far as they match."
        !            26:   (interactive)
        !            27:   (let (p1 p2 np1 np2 maxp1 maxp2 b1 b2 w2
        !            28:           success size
        !            29:           (opoint (point)))
        !            30:     (setq p1 (point) b1 (current-buffer))
        !            31:     (setq w2 (next-window (selected-window)))
        !            32:     (if (eq w2 (selected-window))
        !            33:        (error "No other window."))
        !            34:     (setq p2 (window-point w2)
        !            35:          b2 (window-buffer w2))
        !            36:     (setq maxp1 (point-max))
        !            37:     (save-excursion
        !            38:      (set-buffer b2)
        !            39:      (setq maxp2 (point-max)))
        !            40: 
        !            41:     (setq losep1 (+ 10 maxp1) losep2 (+ 10 maxp2))
        !            42: 
        !            43:     ;; Try advancing comparing 1000 chars at a time.
        !            44:     ;; When that fails, go 500 chars at a time, and so on.
        !            45:     (setq size 1000)
        !            46:     (while (> size 0)
        !            47:       (setq success t)
        !            48:       (while success
        !            49:        (setq np2 (min (+ p2 size) maxp2))
        !            50:        (setq np1 (min (+ p1 size) maxp1))
        !            51:        (save-excursion
        !            52:         (set-buffer b2)
        !            53:         (setq s2 (buffer-substring p2 np2)))
        !            54:        (setq s1 (buffer-substring p1 np1))
        !            55:        (setq success (and (/= np1 p1) (equal s1 s2)))
        !            56:        ;; Don't bother retrying the last fraction of what already lost.
        !            57:        (and success
        !            58:             (or (> (+ p2 size) (- losep2 3))
        !            59:                 (> (+ p1 size) (- losep1 3)))
        !            60:             (> size 1)
        !            61:             (setq success nil))
        !            62:        (if success
        !            63:            (setq p1 np1 p2 np2)
        !            64:          (setq losep1 np1 losep2 np2
        !            65:                maxp1 np1 maxp2 np2)))
        !            66:       (setq size (min (- maxp1 p1) (- maxp2 p2) (/ size 2))))
        !            67: 
        !            68:     (goto-char p1)
        !            69:     (set-window-point w2 p2)
        !            70:     (if (= (point) opoint)
        !            71:        (ding))))

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.