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Diffstat (limited to 'lisp/gnus/gnus-range.el')
| -rw-r--r-- | lisp/gnus/gnus-range.el | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/lisp/gnus/gnus-range.el b/lisp/gnus/gnus-range.el index 5eb8080ac0a..a4262df5328 100644 --- a/lisp/gnus/gnus-range.el +++ b/lisp/gnus/gnus-range.el @@ -59,6 +59,36 @@ 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." |