+(defun notmuch-search-interactive-region ()
+ "Return the bounds of the current interactive region.
+
+This returns (BEG END), where BEG and END are the bounds of the
+region if the region is active, or both `point' otherwise."
+ (if (region-active-p)
+ (list (region-beginning) (region-end))
+ (list (point) (point))))
+
+(defun notmuch-search-interactive-tag-changes (&optional initial-input)
+ "Prompt for tag changes for the current thread or region.
+
+Returns (TAG-CHANGES REGION-BEGIN REGION-END)."
+ (let* ((region (notmuch-search-interactive-region))
+ (beg (first region)) (end (second region))
+ (prompt (if (= beg end) "Tag thread" "Tag region")))
+ (cons (notmuch-read-tag-changes
+ (notmuch-search-get-tags-region beg end) prompt initial-input)
+ region)))
+
+(defun notmuch-search-tag (tag-changes &optional beg end)
+ "Change tags for the currently selected thread or region.
+
+See `notmuch-tag' for information on the format of TAG-CHANGES.
+When called interactively, this uses the region if the region is
+active. When called directly, BEG and END provide the region.
+If these are nil or not provided, this applies to the thread at
+point."
+ (interactive (notmuch-search-interactive-tag-changes))
+ (unless (and beg end) (setq beg (point) end (point)))