Improve progressive summaries in Rmail

* lisp/mail/rmailsum.el (rmail-summary-progressively-narrow):
Renamed from 'rmail-summary-apply-filters-consecutively'.  Doc
fix.
(rmail-summary-invert): Renamed from 'rmail-summary-negate'.  Doc
fix.
(rmail-summary-currently-displayed-msgs): Doc fix.
(rmail-summary--exists-1): New function.
(rmail-summary-by-labels, rmail-summary-by-recipients)
(rmail-summary-by-regexp, rmail-summary-by-topic)
(rmail-summary-by-senders): Call 'rmail-summary-exists' to verify
that the summary is usable.

diff --git a/lisp/mail/rmailsum.el b/lisp/mail/rmailsum.el
index 0144a34e5e717e54533741eeb5abdbf815c6c047..d72464cb81a5eb8658d8068df1692113c2871ef5 100644 (file)
--- a/lisp/mail/rmailsum.el
+++ b/lisp/mail/rmailsum.el
@@ -50,21 +50,26 @@ Setting this option to nil might speed up the generation of summaries."
   :type 'boolean
   :group 'rmail-summary)
 
-(defcustom rmail-summary-apply-filters-consecutively nil
-  "If non-nil, Rmail summary commands apply filtering on top existing filtering.
-When this variable is non-nil, `rmail-summary-by-*' commands work on the
-current summary, and so their filtering can be stacked one on top of another.
-This allows gradual narrowing of the selection of the messages."
+(defcustom rmail-summary-progressively-narrow nil
+  "Non-nil means progressively narrow the set of messages produced by summary.
+This allows to apply the summary criteria on top one another,
+thus progressively narrowing the selection of the messages produced
+by each summary criteria.
+For example, applying `rmail-summary-by-senders' on top
+of `rmail-summary-by-topic' produces a summary of messages
+with the specified Subjects that were sent from specified
+sending addresses.
+This way, the user can apply one summary on top of another,
+and keep narrowing the resulting list of messages."
   :type 'boolean
   :version "29.1"
   :group 'rmail-summary)
 
 (defvar rmail-summary-currently-displayed-msgs nil
-  "String made of `y' and `n'.
-The character at position i tells wether message i is shown in the
-summary or not.  First character is ignored.
-Used when applying `rmail-summary-by-*' commands consecutively.  Filled
-by `rmail-summary-fill-displayed-messages'.")
+  "Boolean vector that tells which messages are displayed in the summary.
+First element is ignored.  Used when applying rmail-summary-by-*
+commands consecutively.  Filled by
+`rmail-summary-populate-displayed-messages'.")
 (put 'rmail-summary-currently-displayed-msgs 'permanent-local t)
 
 (defvar rmail-summary-font-lock-keywords
@@ -284,33 +289,40 @@ by `rmail-summary-fill-displayed-messages'.")
 (defun rmail-update-summary (&rest _)
   (apply (car rmail-summary-redo) (cdr rmail-summary-redo)))
 
-(defun rmail-summary-fill-displayed-messages ()
-  "Fill the rmail-summary-currently-displayed-msgs string."
+(defun rmail-summary-populate-displayed-messages ()
+  "Populate the `rmail-summary-currently-displayed-msgs' vector."
   (with-current-buffer rmail-buffer
-    (with-current-buffer rmail-summary-buffer
-      (setq rmail-summary-currently-displayed-msgs
-           (make-string (1+ rmail-total-messages) ?n))
-      (goto-char (point-min))
-      (while (not (eobp))
-       (aset rmail-summary-currently-displayed-msgs
-             (string-to-number (thing-at-point 'line))
-             ?y)
-       (forward-line 1)))))
-
-(defun rmail-summary-negate ()
-  "Toggle display of messages that match the summary and those which do not."
+    (let ((totmsgs rmail-total-messages))
+      (with-current-buffer rmail-summary-buffer
+       (setq rmail-summary-currently-displayed-msgs
+             (make-bool-vector (1+ totmsgs) nil))
+       (goto-char (point-min))
+       (while (not (eobp))
+         (aset rmail-summary-currently-displayed-msgs
+               (string-to-number (thing-at-point 'line))
+               t)
+         (forward-line 1))))))
+
+(defun rmail-summary-invert ()
+  "Invert the criteria of the current summary.
+That is, show the messages that are not displayed, and hide
+the messages that are displayed."
   (interactive)
-  (rmail-summary-fill-displayed-messages)
-  (rmail-new-summary "Negate"
+  (rmail-summary-populate-displayed-messages)
+  (rmail-new-summary "Invert"
                     '(rmail-summary-by-regexp ".*")
                     (lambda (msg)
                       (if
-                          (= (aref rmail-summary-currently-displayed-msgs msg)
-                             ?n)
-                          (progn
-                            (aset rmail-summary-currently-displayed-msgs msg ?y) t)
-                        (progn
-                          (aset rmail-summary-currently-displayed-msgs msg ?n) nil)))))
+                          (eq (aref rmail-summary-currently-displayed-msgs msg)
+                              nil)
+                          (aset rmail-summary-currently-displayed-msgs msg t)
+                        (aset rmail-summary-currently-displayed-msgs msg nil)))))
+
+(defun rmail-summary--exists-1 ()
+  "Like `rmail-summary-exists', but works in both main and summary buffers."
+  (with-current-buffer rmail-buffer
+    (and rmail-summary-buffer (buffer-name rmail-summary-buffer)
+        rmail-summary-buffer)))
 
 ;;;###autoload
 (defun rmail-summary ()
@@ -327,14 +339,16 @@ LABELS should be a string containing the desired labels, separated by commas."
       (setq labels (or rmail-last-multi-labels
                       (error "No label specified"))))
   (setq rmail-last-multi-labels labels)
-  (if rmail-summary-apply-filters-consecutively
-      (rmail-summary-fill-displayed-messages))
+  (if (and rmail-summary-progressively-narrow
+          (rmail-summary--exists-1))
+      (rmail-summary-populate-displayed-messages))
   (rmail-new-summary (concat "labels " labels)
                     (list 'rmail-summary-by-labels labels)
-                    (if rmail-summary-apply-filters-consecutively
+                    (if (and rmail-summary-progressively-narrow
+                             (rmail-summary--exists-1))
                         (lambda (msg l)
-                          (and (= (aref rmail-summary-currently-displayed-msgs msg)
-                                  ?y)
+                          (and (eq (aref rmail-summary-currently-displayed-msgs msg)
+                                   t)
                                (rmail-message-labels-p msg l)))
                       'rmail-message-labels-p)
                     (concat " \\("
@@ -349,15 +363,17 @@ but if PRIMARY-ONLY is non-nil (prefix arg given),
  only look in the To and From fields.
 RECIPIENTS is a regular expression."
   (interactive "sRecipients to summarize by: \nP")
-  (if rmail-summary-apply-filters-consecutively
-      (rmail-summary-fill-displayed-messages))
+  (if (and rmail-summary-progressively-narrow
+          (rmail-summary--exists-1))
+      (rmail-summary-populate-displayed-messages))
   (rmail-new-summary
    (concat "recipients " recipients)
    (list 'rmail-summary-by-recipients recipients primary-only)
-   (if rmail-summary-apply-filters-consecutively
+   (if (and rmail-summary-progressively-narrow
+           (rmail-summary--exists-1))
        (lambda (msg r &optional po)
-        (and (= (aref rmail-summary-currently-displayed-msgs msg)
-                ?y)
+        (and (eq (aref rmail-summary-currently-displayed-msgs msg)
+                 t)
              (rmail-message-recipients-p msg r po)))
      'rmail-message-recipients-p)
    recipients primary-only))
@@ -388,14 +404,16 @@ Emacs will list the message in the summary."
       (setq regexp (or rmail-last-regexp
                         (error "No regexp specified"))))
   (setq rmail-last-regexp regexp)
-  (if rmail-summary-apply-filters-consecutively
-      (rmail-summary-fill-displayed-messages))
+  (if (and rmail-summary-progressively-narrow
+          (rmail-summary--exists-1))
+      (rmail-summary-populate-displayed-messages))
   (rmail-new-summary (concat "regexp " regexp)
                     (list 'rmail-summary-by-regexp regexp)
-                    (if rmail-summary-apply-filters-consecutively
+                    (if (and rmail-summary-progressively-narrow
+                             (rmail-summary--exists-1))
                         (lambda (msg r)
-                          (and (= (aref rmail-summary-currently-displayed-msgs msg)
-                                  ?y)
+                          (and (eq (aref rmail-summary-currently-displayed-msgs msg)
+                                   t)
                                (rmail-message-regexp-p msg r)))
                       'rmail-message-regexp-p)
                      regexp))
@@ -443,15 +461,17 @@ SUBJECT is a regular expression."
                          (if subject ", default current subject" "")
                          "): ")))
      (list (read-string prompt nil nil subject) current-prefix-arg)))
-  (if rmail-summary-apply-filters-consecutively
-      (rmail-summary-fill-displayed-messages))
+  (if (and rmail-summary-progressively-narrow
+          (rmail-summary--exists-1))
+      (rmail-summary-populate-displayed-messages))
   (rmail-new-summary
    (concat "about " subject)
    (list 'rmail-summary-by-topic subject whole-message)
-   (if rmail-summary-apply-filters-consecutively
+   (if (and rmail-summary-progressively-narrow
+           (rmail-summary--exists-1))
        (lambda (msg s &optional wm)
-        (and (= (aref rmail-summary-currently-displayed-msgs msg)
-                ?y)
+        (and (eq (aref rmail-summary-currently-displayed-msgs msg)
+                 t)
              (rmail-message-subject-p msg s wm)))
      'rmail-message-subject-p)
    subject whole-message))
@@ -477,15 +497,17 @@ sender of the current message."
                          (if sender ", default this message's sender" "")
                          "): ")))
      (list (read-string prompt nil nil sender))))
-  (if rmail-summary-apply-filters-consecutively
-      (rmail-summary-fill-displayed-messages))
+  (if (and rmail-summary-progressively-narrow
+          (rmail-summary--exists-1))
+      (rmail-summary-populate-displayed-messages))
   (rmail-new-summary
    (concat "senders " senders)
    (list 'rmail-summary-by-senders senders)
-   (if rmail-summary-apply-filters-consecutively
+   (if (and rmail-summary-progressively-narrow
+           (rmail-summary--exists-1))
        (lambda (msg s)
-        (and (= (aref rmail-summary-currently-displayed-msgs msg)
-                ?y)
+        (and (eq (aref rmail-summary-currently-displayed-msgs msg)
+                 t)
              (rmail-message-senders-p msg s)))
      'rmail-message-senders-p)
    senders))