diff options
Diffstat (limited to 'lisp/gnus/gnus-range.el')
| -rw-r--r-- | lisp/gnus/gnus-range.el | 214 |
1 files changed, 208 insertions, 6 deletions
diff --git a/lisp/gnus/gnus-range.el b/lisp/gnus/gnus-range.el index b31fc673bb8..56a1b569418 100644 --- a/lisp/gnus/gnus-range.el +++ b/lisp/gnus/gnus-range.el @@ -1,6 +1,7 @@ ;;; gnus-range.el --- range and sequence functions for Gnus -;; Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc. +;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002 +;; Free Software Foundation, Inc. ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org> ;; Keywords: news @@ -30,6 +31,11 @@ ;;; List and range functions +(defsubst gnus-range-normalize (range) + "Normalize RANGE. +If RANGE is a single range, return (RANGE). Otherwise, return RANGE." + (if (listp (cdr-safe range)) range (list range))) + (defun gnus-last-element (list) "Return last element of LIST." (while (cdr list) @@ -55,6 +61,85 @@ (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. +Both lists have to be sorted over <. +The tail of LIST1 is not copied." + (let (out) + (while (and list1 list2) + (cond ((= (car list1) (car list2)) + (setq list1 (cdr list1) + list2 (cdr list2))) + ((< (car list1) (car list2)) + (setq out (cons (car list1) out)) + (setq list1 (cdr list1))) + (t + (setq list2 (cdr list2))))) + (nconc (nreverse out) list1))) + +;;;###autoload +(defun gnus-sorted-ndifference (list1 list2) + "Return a list of elements of LIST1 that do not appear in LIST2. +Both lists have to be sorted over <. +LIST1 is modified." + (let* ((top (cons nil list1)) + (prev top)) + (while (and list1 list2) + (cond ((= (car list1) (car list2)) + (setcdr prev (cdr list1)) + (setq list1 (cdr list1) + list2 (cdr list2))) + ((< (car list1) (car list2)) + (setq prev list1 + list1 (cdr list1))) + (t + (setq list2 (cdr list2))))) + (cdr top))) + +;;;###autoload (defun gnus-sorted-complement (list1 list2) "Return a list of elements that are in LIST1 or LIST2 but not both. Both lists have to be sorted over <." @@ -73,6 +158,7 @@ Both lists have to be sorted over <." (setq list2 (cdr list2))))) (nconc (nreverse out) (or list1 list2))))) +;;;###autoload (defun gnus-intersection (list1 list2) (let ((result nil)) (while list2 @@ -81,8 +167,10 @@ Both lists have to be sorted over <." (setq list2 (cdr list2))) result)) +;;;###autoload (defun gnus-sorted-intersection (list1 list2) - ;; LIST1 and LIST2 have to be sorted over <. + "Return intersection of LIST1 and LIST2. +LIST1 and LIST2 have to be sorted over <." (let (out) (while (and list1 list2) (cond ((= (car list1) (car list2)) @@ -95,9 +183,13 @@ Both lists have to be sorted over <." (setq list2 (cdr list2))))) (nreverse out))) -(defun gnus-set-sorted-intersection (list1 list2) - ;; LIST1 and LIST2 have to be sorted over <. - ;; This function modifies LIST1. +;;;###autoload +(defalias 'gnus-set-sorted-intersection 'gnus-sorted-nintersection) + +;;;###autoload +(defun gnus-sorted-nintersection (list1 list2) + "Return intersection of LIST1 and LIST2 by modifying cdr pointers of LIST1. +LIST1 and LIST2 have to be sorted over <." (let* ((top (cons nil list1)) (prev top)) (while (and list1 list2) @@ -113,6 +205,55 @@ Both lists have to be sorted over <." (setcdr prev nil) (cdr top))) +;;;###autoload +(defun gnus-sorted-union (list1 list2) + "Return union of LIST1 and LIST2. +LIST1 and LIST2 have to be sorted over <." + (let (out) + (while (and list1 list2) + (cond ((= (car list1) (car list2)) + (setq out (cons (car list1) out) + list1 (cdr list1) + list2 (cdr list2))) + ((< (car list1) (car list2)) + (setq out (cons (car list1) out) + list1 (cdr list1))) + (t + (setq out (cons (car list2) out) + list2 (cdr list2))))) + (while list1 + (setq out (cons (car list1) out) + list1 (cdr list1))) + (while list2 + (setq out (cons (car list2) out) + list2 (cdr list2))) + (nreverse out))) + +;;;###autoload +(defun gnus-sorted-nunion (list1 list2) + "Return union of LIST1 and LIST2 by modifying cdr pointers of LIST1. +LIST1 and LIST2 have to be sorted over <." + (let* ((top (cons nil list1)) + (prev top)) + (while (and list1 list2) + (cond ((= (car list1) (car list2)) + (setq prev list1 + list1 (cdr list1) + list2 (cdr list2))) + ((< (car list1) (car list2)) + (setq prev list1 + list1 (cdr list1))) + (t + (setcdr prev (list (car list2))) + (setq prev (cdr prev) + list2 (cdr list2)) + (setcdr prev list1)))) + (while list2 + (setcdr prev (list (car list2))) + (setq prev (cdr prev) + list2 (cdr list2))) + (cdr top))) + (defun gnus-compress-sequence (numbers &optional always-list) "Convert 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 @@ -319,9 +460,58 @@ modified." (setq ranges (cdr ranges))) (not not-stop)))) +(defun gnus-list-range-intersection (list ranges) + "Return a list of numbers in LIST that are members of RANGES. +LIST is a sorted list." + (setq ranges (gnus-range-normalize ranges)) + (let (number result) + (while (setq number (pop list)) + (while (and ranges + (if (numberp (car ranges)) + (< (car ranges) number) + (< (cdar ranges) number))) + (setq ranges (cdr ranges))) + (when (and ranges + (if (numberp (car ranges)) + (= (car ranges) number) + ;; (caar ranges) <= number <= (cdar ranges) + (>= number (caar ranges)))) + (push number result))) + (nreverse result))) + +(defalias 'gnus-inverse-list-range-intersection 'gnus-list-range-difference) + +(defun gnus-list-range-difference (list ranges) + "Return a list of numbers in LIST that are not members of RANGES. +LIST is a sorted list." + (setq ranges (gnus-range-normalize ranges)) + (let (number result) + (while (setq number (pop list)) + (while (and ranges + (if (numberp (car ranges)) + (< (car ranges) number) + (< (cdar ranges) number))) + (setq ranges (cdr ranges))) + (when (or (not ranges) + (if (numberp (car ranges)) + (not (= (car ranges) number)) + ;; not ((caar ranges) <= number <= (cdar ranges)) + (< number (caar ranges)))) + (push number result))) + (nreverse result))) + (defun gnus-range-length (range) "Return the length RANGE would have if uncompressed." - (length (gnus-uncompress-range range))) + (cond + ((null range) + 0) + ((not (listp (cdr range))) + (- (cdr range) (car range) -1)) + (t + (let ((sum 0)) + (dolist (x range sum) + (setq sum + (+ sum (if (consp x) (- (cdr x) (car x) -1) 1)))))))) (defun gnus-sublist-p (list sublist) "Test whether all elements in SUBLIST are members of LIST." @@ -387,6 +577,18 @@ modified." (if item (push item range)) (reverse range))) +;;;###autoload +(defun gnus-add-to-sorted-list (list num) + "Add NUM into sorted LIST by side effect." + (let* ((top (cons nil list)) + (prev top)) + (while (and list (< (car list) num)) + (setq prev list + list (cdr list))) + (unless (eq (car list) num) + (setcdr prev (cons num list))) + (cdr top))) + (provide 'gnus-range) ;;; arch-tag: 4780bdd8-5a15-4aff-be28-18727895b6ad |