Merge from emacs-23; up to 2010-06-03T05:41:49Z!rgm@gnu.org.

[gnu-emacs] / lisp / gnus / gnus-range.el

diff --git a/lisp/gnus/gnus-range.el b/lisp/gnus/gnus-range.el
index e75c975d718a838943a1247f510c0c5b06b9b368..ce5a837eaef8ac9db17925bf2f94f6e3cf5f1f59 100644 (file)
--- a/lisp/gnus/gnus-range.el
+++ b/lisp/gnus/gnus-range.el
@@ -1,7 +1,6 @@
 ;;; gnus-range.el --- range and sequence functions for Gnus
 
-;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
-;;   2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+;; Copyright (C) 1996-2011 Free Software Foundation, Inc.
 
 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
 ;; Keywords: news
@@ -59,6 +58,36 @@ If RANGE is a single range, return (RANGE). Otherwise, return RANGE."
       (setq list2 (cdr list2)))
     list1))
 
+(defun gnus-range-nconcat (&rest ranges)
+  "Return a range comprising all the RANGES, which are pre-sorted.
+RANGES will be destructively altered."
+  (setq ranges (delete nil ranges))
+  (let* ((result (gnus-range-normalize (pop ranges)))
+        (last (last result)))
+    (dolist (range ranges)
+      (setq range (gnus-range-normalize range))
+      ;; Normalize the single-number case, so that we don't need to
+      ;; special-case that so much.
+      (when (numberp (car last))
+       (setcar last (cons (car last) (car last))))
+      (when (numberp (car range))
+       (setcar range (cons (car range) (car range))))
+      (if (= (1+ (cdar last)) (caar range))
+         (progn
+           (setcdr (car last) (cdar range))
+           (setcdr last (cdr range)))
+       (setcdr last range)
+       ;; Denormalize back, since we couldn't join the ranges up.
+       (when (= (caar range) (cdar range))
+         (setcar range (caar range)))
+       (when (= (caar last) (cdar last))
+         (setcar last (caar last))))
+      (setq last (last last)))
+    (if (and (consp (car result))
+            (= (length result) 1))
+       (car result)
+      result)))
+
 (defun gnus-range-difference (range1 range2)
   "Return the range of elements in RANGE1 that do not appear in RANGE2.
 Both ranges must be in ascending order."
@@ -654,5 +683,4 @@ LIST is a sorted list."
 
 (provide 'gnus-range)
 
-;; arch-tag: 4780bdd8-5a15-4aff-be28-18727895b6ad
 ;;; gnus-range.el ends here