[PATCH 3/6] emacs: make "+" and "-" tagging operations more robust

[Dmitry Kurochkin <dmitry.kurochkin@gmail.com>]

Before the change, "+" and "-" tagging operations in notmuch-search
and notmuch-show views accepted only a single tag.  The patch makes
them use the recently added `notmuch-select-tags-with-completion'
function, which allows to enter multiple tags with "+" and "-"
prefixes.  So after the change, "+" and "-" bindings allow to both add
and remove multiple tags.  The only difference between "+" and "-" is
the minibuffer initial input ("+" and "-" respectively).
---
 emacs/notmuch-show.el |   65 +++++++------------
 emacs/notmuch.el      |  165 +++++++++++++++++++++++++------------------------
 2 files changed, 107 insertions(+), 123 deletions(-)

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 84ac624..03eadfb 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -38,8 +38,9 @@
 
 (declare-function notmuch-call-notmuch-process "notmuch" (&rest args))
 (declare-function notmuch-fontify-headers "notmuch" nil)
-(declare-function notmuch-select-tag-with-completion "notmuch" (prompt &rest search-terms))
+(declare-function notmuch-select-tags-with-completion "notmuch" (&optional initial-input &rest search-terms))
 (declare-function notmuch-search-show-thread "notmuch" nil)
+(declare-function notmuch-update-tags "notmuch" (current-tags changed-tags))
 
 (defcustom notmuch-message-headers '("Subject" "To" "Cc" "Date")
   "Headers that should be shown in a message, in this order.
@@ -1267,7 +1268,7 @@ Some useful entries are:
 
 (defun notmuch-show-mark-read ()
   "Mark the current message as read."
-  (notmuch-show-remove-tag "unread"))
+  (notmuch-show-tag-message "-unread"))
 
 ;; Functions for getting attributes of several messages in the current
 ;; thread.
@@ -1470,51 +1471,33 @@ than only the current message."
 	    (message (format "Command '%s' exited abnormally with code %d"
 			     shell-command exit-code))))))))
 
-(defun notmuch-show-add-tags-worker (current-tags add-tags)
-  "Add to `current-tags' with any tags from `add-tags' not
-currently present and return the result."
-  (let ((result-tags (copy-sequence current-tags)))
-    (mapc (lambda (add-tag)
-	    (unless (member add-tag current-tags)
-	      (setq result-tags (push add-tag result-tags))))
-	    add-tags)
-    (sort result-tags 'string<)))
-
-(defun notmuch-show-del-tags-worker (current-tags del-tags)
-  "Remove any tags in `del-tags' from `current-tags' and return
-the result."
-  (let ((result-tags (copy-sequence current-tags)))
-    (mapc (lambda (del-tag)
-	    (setq result-tags (delete del-tag result-tags)))
-	  del-tags)
-    result-tags))
-
-(defun notmuch-show-add-tag (&rest toadd)
-  "Add a tag to the current message."
-  (interactive
-   (list (notmuch-select-tag-with-completion "Tag to add: ")))
+(defun notmuch-show-tag-message (&rest changed-tags)
+  "Change tags for the current message.
 
+`Changed-tags' is a list of tag operations for \"notmuch tag\",
+i.e. a list of tags to change with '+' and '-' prefixes."
   (let* ((current-tags (notmuch-show-get-tags))
-	 (new-tags (notmuch-show-add-tags-worker current-tags toadd)))
-
+	 (new-tags (notmuch-update-tags current-tags changed-tags)))
     (unless (equal current-tags new-tags)
-      (apply 'notmuch-tag (notmuch-show-get-message-id)
-	     (mapcar (lambda (s) (concat "+" s)) toadd))
+      (apply 'notmuch-tag (notmuch-show-get-message-id) changed-tags)
       (notmuch-show-set-tags new-tags))))
 
-(defun notmuch-show-remove-tag (&rest toremove)
-  "Remove a tag from the current message."
-  (interactive
-   (list (notmuch-select-tag-with-completion
-	  "Tag to remove: " (notmuch-show-get-message-id))))
+(defun notmuch-show-tag (&optional initial-input)
+  "Change tags for the current message, read input from the minibuffer."
+  (interactive)
+  (let ((changed-tags (notmuch-select-tags-with-completion
+		       initial-input (notmuch-show-get-message-id))))
+    (apply 'notmuch-show-tag-message changed-tags)))
 
-  (let* ((current-tags (notmuch-show-get-tags))
-	 (new-tags (notmuch-show-del-tags-worker current-tags toremove)))
+(defun notmuch-show-add-tag ()
+  "Same as `notmuch-show-tag' but sets initial input to '+'."
+  (interactive)
+  (notmuch-show-tag "+"))
 
-    (unless (equal current-tags new-tags)
-      (apply 'notmuch-tag (notmuch-show-get-message-id)
-	     (mapcar (lambda (s) (concat "-" s)) toremove))
-      (notmuch-show-set-tags new-tags))))
+(defun notmuch-show-remove-tag ()
+  "Same as `notmuch-show-tag' but sets initial input to '-'."
+  (interactive)
+  (notmuch-show-tag "-"))
 
 (defun notmuch-show-toggle-headers ()
   "Toggle the visibility of the current message headers."
@@ -1559,7 +1542,7 @@ argument, hide all of the messages."
 (defun notmuch-show-archive-thread-internal (show-next)
   ;; Remove the tag from the current set of messages.
   (goto-char (point-min))
-  (loop do (notmuch-show-remove-tag "inbox")
+  (loop do (notmuch-show-tag-message "-inbox")
 	until (not (notmuch-show-goto-message-next)))
   ;; Move to the next item in the search results, if any.
   (let ((parent-buffer notmuch-show-parent-buffer))
diff --git a/emacs/notmuch.el b/emacs/notmuch.el
index ff46617..24b0ea3 100644
--- a/emacs/notmuch.el
+++ b/emacs/notmuch.el
@@ -76,38 +76,56 @@ For example:
 (defvar notmuch-query-history nil
   "Variable to store minibuffer history for notmuch queries")
 
-(defun notmuch-tag-completions (&optional prefixes search-terms)
-  (let ((tag-list
-	 (split-string
-	  (with-output-to-string
-	    (with-current-buffer standard-output
-	      (apply 'call-process notmuch-command nil t
-		     nil "search-tags" search-terms)))
-	  "\n+" t)))
-    (if (null prefixes)
-	tag-list
-      (apply #'append
-	     (mapcar (lambda (tag)
-		       (mapcar (lambda (prefix)
-				 (concat prefix tag)) prefixes))
-		     tag-list)))))
+(defun notmuch-tag-completions (&optional search-terms)
+  (split-string
+   (with-output-to-string
+     (with-current-buffer standard-output
+       (apply 'call-process notmuch-command nil t
+	      nil "search-tags" search-terms)))
+   "\n+" t))
 
 (defun notmuch-select-tag-with-completion (prompt &rest search-terms)
-  (let ((tag-list (notmuch-tag-completions nil search-terms)))
+  (let ((tag-list (notmuch-tag-completions search-terms)))
     (completing-read prompt tag-list)))
 
-(defun notmuch-select-tags-with-completion (prompt &optional prefixes &rest search-terms)
-  (let ((tag-list (notmuch-tag-completions prefixes search-terms))
-	(crm-separator " ")
-	;; By default, space is bound to "complete word" function.
-	;; Re-bind it to insert a space instead.  Note that <tab>
-	;; still does the completion.
-	(crm-local-completion-map
-	 (let ((map (make-sparse-keymap)))
-	   (set-keymap-parent map crm-local-completion-map)
-	   (define-key map " " 'self-insert-command)
-	   map)))
-    (delete "" (completing-read-multiple prompt tag-list))))
+(defun notmuch-select-tags-with-completion (&optional initial-input &rest search-terms)
+  (let* ((add-tag-list (mapcar (apply-partially 'concat "+")
+			       (notmuch-tag-completions)))
+	 (remove-tag-list (mapcar (apply-partially 'concat "-")
+				  (notmuch-tag-completions search-terms)))
+	 (tag-list (append add-tag-list remove-tag-list))
+	 (crm-separator " ")
+	 ;; By default, space is bound to "complete word" function.
+	 ;; Re-bind it to insert a space instead.  Note that <tab>
+	 ;; still does the completion.
+	 (crm-local-completion-map
+	  (let ((map (make-sparse-keymap)))
+	    (set-keymap-parent map crm-local-completion-map)
+	    (define-key map " " 'self-insert-command)
+	    map)))
+    (delete "" (completing-read-multiple
+		"Operations (+add -drop): notmuch tag " tag-list nil
+		nil initial-input))))
+
+(defun notmuch-update-tags (current-tags changed-tags)
+  "Update `current-tags' with `changed-tags' and return the result.
+
+`Changed-tags' is a list of tag operations given to \"notmuch
+tag\", i.e. a list of changed tags with '+' and '-' prefixes."
+  (let ((result-tags (copy-sequence current-tags)))
+    (mapc (lambda (changed-tag)
+	    (unless (string= changed-tag "")
+	      (let ((op (substring changed-tag 0 1))
+		    (tag (substring changed-tag 1)))
+		(cond ((string= op "+")
+		       (unless (member tag result-tags)
+			 (push tag result-tags)))
+		      ((string= op "-")
+		       (setq result-tags (delete tag result-tags)))
+		      (t
+		       (error "Changed tag must be of the form `+this_tag' or `-that_tag'"))))))
+       changed-tags)
+    (sort result-tags 'string<)))
 
 (defun notmuch-foreach-mime-part (function mm-handle)
   (cond ((stringp (car mm-handle))
@@ -447,6 +465,10 @@ Complete list of currently available key bindings:
   "Return a list of threads for the current region"
   (notmuch-search-properties-in-region 'notmuch-search-thread-id beg end))
 
+(defun notmuch-search-find-thread-id-region-search (beg end)
+  "Return a search string for threads for the current region"
+  (mapconcat 'identity (notmuch-search-find-thread-id-region beg end) " or "))
+
 (defun notmuch-search-find-authors ()
   "Return the authors for the current thread"
   (get-text-property (point) 'notmuch-search-authors))
@@ -590,74 +612,55 @@ the messages that were tagged"
 	(forward-line 1))
       output)))
 
-(defun notmuch-search-add-tag-thread (tag)
-  (notmuch-search-add-tag-region tag (point) (point)))
+(defun notmuch-search-tag-thread (&rest tags)
+  "Change tags for the currently selected thread.
 
-(defun notmuch-search-add-tag-region (tag beg end)
-  (let ((search-id-string (mapconcat 'identity (notmuch-search-find-thread-id-region beg end) " or ")))
-    (notmuch-tag search-id-string (concat "+" tag))
-    (save-excursion
-      (let ((last-line (line-number-at-pos end))
-	    (max-line (- (line-number-at-pos (point-max)) 2)))
-	(goto-char beg)
-	(while (<= (line-number-at-pos) (min last-line max-line))
-	  (notmuch-search-set-tags (delete-dups (sort (cons tag (notmuch-search-get-tags)) 'string<)))
-	  (forward-line))))))
+See `notmuch-search-tag-region' for details."
+  (apply 'notmuch-search-tag-region (point) (point) tags))
 
-(defun notmuch-search-remove-tag-thread (tag)
-  (notmuch-search-remove-tag-region tag (point) (point)))
+(defun notmuch-search-tag-region (beg end &rest tags)
+  "Change tags for threads in the given region.
 
-(defun notmuch-search-remove-tag-region (tag beg end)
-  (let ((search-id-string (mapconcat 'identity (notmuch-search-find-thread-id-region beg end) " or ")))
-    (notmuch-tag search-id-string (concat "-" tag))
+`Tags' is a list of tag operations for \"notmuch tag\", i.e. a
+list of tags to change with '+' and '-' prefixes.  The tags are
+added or removed for all threads in the region from `beg' to
+`end'."
+  (let ((search-string (notmuch-search-find-thread-id-region-search beg end)))
+    (apply 'notmuch-tag search-string tags)
     (save-excursion
       (let ((last-line (line-number-at-pos end))
 	    (max-line (- (line-number-at-pos (point-max)) 2)))
 	(goto-char beg)
 	(while (<= (line-number-at-pos) (min last-line max-line))
-	  (notmuch-search-set-tags (delete tag (notmuch-search-get-tags)))
+	  (notmuch-search-set-tags
+	   (notmuch-update-tags (notmuch-search-get-tags) tags))
 	  (forward-line))))))
 
-(defun notmuch-search-add-tag (tag)
-  "Add a tag to the currently selected thread or region.
-
-The tag is added to all messages in the currently selected thread
-or threads in the current region."
-  (interactive
-   (list (notmuch-select-tag-with-completion "Tag to add: ")))
-  (save-excursion
-    (if (region-active-p)
-	(let* ((beg (region-beginning))
-	       (end (region-end)))
-	  (notmuch-search-add-tag-region tag beg end))
-      (notmuch-search-add-tag-thread tag))))
-
-(defun notmuch-search-remove-tag (tag)
-  "Remove a tag from the currently selected thread or region.
+(defun notmuch-search-tag (&optional initial-input)
+  "Change tags for the currently selected thread or region."
+  (interactive)
+  (let* ((beg (if (region-active-p) (region-beginning) (point)))
+	 (end (if (region-active-p) (region-end) (point)))
+	 (search-string (notmuch-search-find-thread-id-region-search beg end))
+	 (tags (notmuch-select-tags-with-completion initial-input search-string)))
+    (apply 'notmuch-search-tag-region beg end tags)))
+
+(defun notmuch-search-add-tag ()
+  "Same as `notmuch-search-tag' but sets initial input to '+'."
+  (interactive)
+  (notmuch-search-tag "+"))
 
-The tag is removed from all messages in the currently selected
-thread or threads in the current region."
-  (interactive
-   (list (notmuch-select-tag-with-completion
-	  "Tag to remove: "
-	  (if (region-active-p)
-	      (mapconcat 'identity
-			 (notmuch-search-find-thread-id-region (region-beginning) (region-end))
-			 " ")
-	    (notmuch-search-find-thread-id)))))
-  (save-excursion
-    (if (region-active-p)
-	(let* ((beg (region-beginning))
-	       (end (region-end)))
-	  (notmuch-search-remove-tag-region tag beg end))
-      (notmuch-search-remove-tag-thread tag))))
+(defun notmuch-search-remove-tag ()
+  "Same as `notmuch-search-tag' but sets initial input to '-'."
+  (interactive)
+  (notmuch-search-tag "-"))
 
 (defun notmuch-search-archive-thread ()
   "Archive the currently selected thread (remove its \"inbox\" tag).
 
 This function advances the next thread when finished."
   (interactive)
-  (notmuch-search-remove-tag-thread "inbox")
+  (notmuch-search-tag-thread "-inbox")
   (notmuch-search-next-thread))
 
 (defvar notmuch-search-process-filter-data nil
@@ -893,9 +896,7 @@ will prompt for tags to be added or removed. Tags prefixed with
 Each character of the tag name may consist of alphanumeric
 characters as well as `_.+-'.
 "
-  (interactive (notmuch-select-tags-with-completion
-		"Operations (+add -drop): notmuch tag "
-		'("+" "-")))
+  (interactive (notmuch-select-tags-with-completion))
   (apply 'notmuch-tag notmuch-search-query-string actions))
 
 (defun notmuch-search-buffer-title (query)
-- 
1.7.8.3