Import No Gnus v0.4.

[elisp/gnus.git-] / lisp / gnus-range.el

diff --git a/lisp/gnus-range.el b/lisp/gnus-range.el
index b609074..13a00dd 100644 (file)
--- a/lisp/gnus-range.el
+++ b/lisp/gnus-range.el
@@ -1,7 +1,7 @@
 ;;; gnus-range.el --- range and sequence functions for Gnus
 
-;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002
-;;        Free Software Foundation, Inc.
+;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
+;;   2005, 2006 Free Software Foundation, Inc.
 
 ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
 ;; Keywords: news
@@ -20,8 +20,8 @@
 
 ;; You should have received a copy of the GNU General Public License
 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
 
 ;;; Commentary:
 
@@ -61,6 +61,48 @@ If RANGE is a single range, return (RANGE). Otherwise, return RANGE."
       (setq list2 (cdr list2)))
     list1))
 
+(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."
+  (setq range1 (gnus-range-normalize range1))
+  (setq range2 (gnus-range-normalize range2))
+  (let* ((new-range (cons nil (copy-sequence range1)))
+         (r new-range)
+         (safe t))
+    (while (cdr r)
+      (let* ((r1 (cadr r))
+             (r2 (car range2))
+             (min1 (if (numberp r1) r1 (car r1)))
+             (max1 (if (numberp r1) r1 (cdr r1)))
+             (min2 (if (numberp r2) r2 (car r2)))
+             (max2 (if (numberp r2) r2 (cdr r2))))
+
+        (cond ((> min1 max1)
+               ;; Invalid range: may result from overlap condition (below)
+               ;; remove Invalid range
+               (setcdr r (cddr r)))
+              ((and (= min1 max1)
+                    (listp r1))
+               ;; Inefficient representation: may result from overlap condition (below)
+               (setcar (cdr r) min1))
+              ((not min2)
+               ;; All done with range2
+               (setq r nil))
+              ((< max1 min2)
+               ;; No overlap: range1 preceeds range2
+               (pop r))
+              ((< max2 min1)
+               ;; No overlap: range2 preceeds range1
+               (pop range2))
+              ((and (<= min2 min1) (<= max1 max2))
+               ;; Complete overlap: range1 removed
+               (setcdr r (cddr r)))
+              (t
+               (setcdr r (nconc (list (cons min1 (1- min2)) (cons (1+ max2) max1)) (cddr r)))))))
+    (cdr new-range)))
+
+
+
 ;;;###autoload
 (defun gnus-sorted-difference (list1 list2)
   "Return a list of elements of LIST1 that do not appear in LIST2.
@@ -142,6 +184,58 @@ LIST1 and LIST2 have to be sorted over <."
     (nreverse out)))
 
 ;;;###autoload
+(defun gnus-sorted-range-intersection (range1 range2)
+  "Return intersection of RANGE1 and RANGE2.
+RANGE1 and RANGE2 have to be sorted over <."
+  (let* (out
+         (min1 (car range1))
+         (max1 (if (numberp min1) 
+                   (if (numberp (cdr range1))
+                       (prog1 (cdr range1)
+                         (setq range1 nil)) min1)
+                 (prog1 (cdr min1)
+                   (setq min1 (car min1)))))
+         (min2 (car range2))
+         (max2 (if (numberp min2)
+                   (if (numberp (cdr range2))
+                       (prog1 (cdr range2) 
+                         (setq range2 nil)) min2) 
+                 (prog1 (cdr min2)
+                   (setq min2 (car min2))))))
+    (setq range1 (cdr range1)
+          range2 (cdr range2))
+    (while (and min1 min2)
+      (cond ((< max1 min2)              ; range1 preceeds range2
+             (setq range1 (cdr range1)
+                   min1 nil))
+            ((< max2 min1)              ; range2 preceeds range1
+             (setq range2 (cdr range2)
+                   min2 nil))
+            (t                     ; some sort of overlap is occurring
+             (let ((min (max min1 min2))
+                   (max (min max1 max2)))
+               (setq out (if (= min max)
+                             (cons min out)
+                           (cons (cons min max) out))))
+             (if (< max1 max2)          ; range1 ends before range2
+                 (setq min1 nil)        ; incr range1
+               (setq min2 nil))))       ; incr range2
+      (unless min1
+        (setq min1 (car range1)
+              max1 (if (numberp min1) min1 (prog1 (cdr min1) (setq min1 (car min1))))
+              range1 (cdr range1)))
+      (unless min2
+        (setq min2 (car range2)
+              max2 (if (numberp min2) min2 (prog1 (cdr min2) (setq min2 (car min2))))
+              range2 (cdr range2))))
+    (cond ((cdr out)
+        (nreverse out))
+          ((numberp (car out))
+           out)
+          (t
+           (car out)))))
+
+;;;###autoload
 (defalias 'gnus-set-sorted-intersection 'gnus-sorted-nintersection)
 
 ;;;###autoload
@@ -213,7 +307,7 @@ LIST1 and LIST2 have to be sorted over <."
     (cdr top)))
 
 (defun gnus-compress-sequence (numbers &optional always-list)
-  "Convert list of numbers to a list of ranges or a single range.
+  "Convert sorted list of numbers to a list of ranges or a single range.
 If ALWAYS-LIST is non-nil, this function will always release a list of
 ranges."
   (let* ((first (car numbers))
@@ -547,6 +641,20 @@ LIST is a sorted list."
       (setcdr prev (cons num list)))
     (cdr top)))
 
+(defun gnus-range-map (func range)
+  "Apply FUNC to each value contained by RANGE."
+  (setq range (gnus-range-normalize range))
+  (while range
+    (let ((span (pop range)))
+      (if (numberp span)
+          (funcall func span)
+        (let ((first (car span))
+              (last (cdr span)))
+          (while (<= first last)
+            (funcall func first)
+            (setq first (1+ first))))))))
+
 (provide 'gnus-range)
 
+;;; arch-tag: 4780bdd8-5a15-4aff-be28-18727895b6ad
 ;;; gnus-range.el ends here