X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/0877d0dc24ee792b9b14592869ea1aa0934aee58..a8e1414c0d66903884059361ecc8ec70da37cf35:/lisp/sort.el

diff --git a/lisp/sort.el b/lisp/sort.el
index 56e97061d1..8bc71388ad 100644
--- a/lisp/sort.el
+++ b/lisp/sort.el
@@ -1,10 +1,10 @@
 ;;; sort.el --- commands to sort text in an Emacs buffer
 
-;; Copyright (C) 1986-1987, 1994-1995, 2001-2013 Free Software
+;; Copyright (C) 1986-1987, 1994-1995, 2001-2016 Free Software
 ;; Foundation, Inc.
 
 ;; Author: Howie Kaye
-;; Maintainer: FSF
+;; Maintainer: emacs-devel@gnu.org
 ;; Keywords: unix
 
 ;; This file is part of GNU Emacs.
@@ -316,7 +316,7 @@ FIELD, BEG and END.  BEG and END specify region to sort."
 ;;			       (point)
 ;;			       (save-excursion
 ;;				 (re-search-forward
-;;				  "[+-]?[0-9]*\.?[0-9]*\\([eE][+-]?[0-9]+\\)?")
+;;				  "[+-]?[0-9]*\\.?[0-9]*\\([eE][+-]?[0-9]+\\)?")
 ;;				 (point))))))
 ;;		 nil))
 
@@ -568,32 +568,35 @@ From a program takes two point or marker arguments, BEG and END."
       (insert (car ll)))))
 
 ;;;###autoload
-(defun delete-duplicate-lines (beg end &optional reverse adjacent interactive)
-  "Delete duplicate lines in the region between BEG and END.
-
-If REVERSE is nil, search and delete duplicates forward keeping the first
-occurrence of duplicate lines.  If REVERSE is non-nil (when called
-interactively with C-u prefix), search and delete duplicates backward
-keeping the last occurrence of duplicate lines.
-
-If ADJACENT is non-nil (when called interactively with two C-u prefixes),
-delete repeated lines only if they are adjacent.  It works like the utility
-`uniq' and is useful when lines are already sorted in a large file since
-this is more efficient in performance and memory usage than when ADJACENT
-is nil that uses additional memory to remember previous lines.
-
-When called from Lisp and INTERACTIVE is omitted or nil, return the number
-of deleted duplicate lines, do not print it; if INTERACTIVE is t, the
-function behaves in all respects as if it had been called interactively."
+(defun delete-duplicate-lines (beg end &optional reverse adjacent keep-blanks
+                               interactive)
+  "Delete all but one copy of any identical lines in the region.
+Non-interactively, arguments BEG and END delimit the region.
+Normally it searches forwards, keeping the first instance of
+each identical line.  If REVERSE is non-nil (interactively, with
+a C-u prefix), it searches backwards and keeps the last instance of
+each repeated line.
+
+Identical lines need not be adjacent, unless the argument
+ADJACENT is non-nil (interactively, with a C-u C-u prefix).
+This is a more efficient mode of operation, and may be useful
+on large regions that have already been sorted.
+
+If the argument KEEP-BLANKS is non-nil (interactively, with a
+C-u C-u C-u prefix), it retains repeated blank lines.
+
+Returns the number of deleted lines.  Interactively, or if INTERACTIVE
+is non-nil, it also prints a message describing the number of deletions."
   (interactive
    (progn
      (barf-if-buffer-read-only)
      (list (region-beginning) (region-end)
 	   (equal current-prefix-arg '(4))
 	   (equal current-prefix-arg '(16))
+	   (equal current-prefix-arg '(64))
 	   t)))
-  (let ((lines (unless adjacent (make-hash-table :weakness 'key :test 'equal)))
-	line prev-line
+  (let ((lines (unless adjacent (make-hash-table :test 'equal)))
+	line prev-line first-line
 	(count 0)
 	(beg (copy-marker beg))
 	(end (copy-marker end)))
@@ -601,18 +604,21 @@ function behaves in all respects as if it had been called interactively."
       (goto-char (if reverse end beg))
       (if (and reverse (bolp)) (forward-char -1))
       (while (if reverse
-		 (and (> (point) beg) (not (bobp)))
+		 (not first-line)
 	       (and (< (point) end) (not (eobp))))
+	(setq first-line (and reverse (or (<= (point) beg) (bobp))))
 	(setq line (buffer-substring-no-properties
 		    (line-beginning-position) (line-end-position)))
-	(if (if adjacent (equal line prev-line) (gethash line lines))
-	    (progn
-	      (delete-region (progn (forward-line 0) (point))
-			     (progn (forward-line 1) (point)))
-	      (if reverse (forward-line -1))
-	      (setq count (1+ count)))
-	  (if adjacent (setq prev-line line) (puthash line t lines))
-	  (forward-line (if reverse -1 1)))))
+        (if (and keep-blanks (string= "" line))
+            (forward-line 1)
+          (if (if adjacent (equal line prev-line) (gethash line lines))
+              (progn
+                (delete-region (progn (forward-line 0) (point))
+                               (progn (forward-line 1) (point)))
+                (if reverse (forward-line -1))
+                (setq count (1+ count)))
+            (if adjacent (setq prev-line line) (puthash line t lines))
+            (forward-line (if reverse -1 1))))))
     (set-marker beg nil)
     (set-marker end nil)
     (when interactive