bug#43413: 28.0.50; [PATCH] New gnus-score-func to support user-defined scoring functions

[Alex Bochannek]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Alex Bochannek <alex@bochannek.com> writes:
>
>> Although it's only ~40 lines of Elisp and ~30 lines of Texinfo, I am
>> pretty sure it's the largest code change I have submitted to Emacs and I
>> would not be surprised if I violated some coding standards. I have spent
>> a fair amount of time with testing, but cannot rule out corner cases, of
>> course. Let me know if you want me to make any improvements before
>> accepting this patch.
>
> Looks pretty good, but the main problem is neglecting to let-bind
> variables.  byte-compiling is a good way to catch these errors:

Please ignore the previous patch I sent that used let-forms, I found a
bug in it. I cleaned it up some more and I am attaching a new
patch. Thanks again for the feedback!

diff --git a/lisp/gnus/gnus-score.el b/lisp/gnus/gnus-score.el
index ffc6b8ca34..2bc9980852 100644
--- a/lisp/gnus/gnus-score.el
+++ b/lisp/gnus/gnus-score.el
@@ -497,6 +497,7 @@ gnus-header-index
     ("head" -1 gnus-score-body)
     ("body" -1 gnus-score-body)
     ("all" -1 gnus-score-body)
+    (score-fn -1 nil)
     ("followup" 2 gnus-score-followup)
     ("thread" 5 gnus-score-thread)))
 
@@ -1175,14 +1176,20 @@ gnus-score-edit-file-at-point
       (when format
        (gnus-score-pretty-print))
       (when (consp rule) ;; the rule exists
-       (setq rule (mapconcat #'(lambda (obj)
-                                 (regexp-quote (format "%S" obj)))
-                             rule
-                             sep))
-       (goto-char (point-min))
-       (re-search-forward rule nil t)
-       ;; make it easy to use `kill-sexp':
-       (goto-char (1- (match-beginning 0)))))))
+       (let (move)
+         (setq rule (if (symbolp (car rule))
+                        (format "(%S)" (car rule))
+                      (mapconcat #'(lambda (obj)
+                                     (regexp-quote (format "%S" obj)))
+                                 rule
+                                 sep)))
+         (goto-char (point-min))
+         (setq move (if (string-match "(.*)" rule)
+                        0
+                      -1))
+         (re-search-forward rule nil t)
+         ;; make it easy to use `kill-sexp':
+         (goto-char (+ move (match-beginning 0))))))))
 
 (defun gnus-score-load-file (file)
   ;; Load score file FILE.  Returns a list a retrieved score-alists.
@@ -1232,6 +1239,7 @@ gnus-score-load-file
     (let ((mark (car (gnus-score-get 'mark alist)))
          (expunge (car (gnus-score-get 'expunge alist)))
          (mark-and-expunge (car (gnus-score-get 'mark-and-expunge alist)))
+         (score-fn (car (gnus-score-get 'score-fn alist)))
          (files (gnus-score-get 'files alist))
          (exclude-files (gnus-score-get 'exclude-files alist))
          (orphan (car (gnus-score-get 'orphan alist)))
@@ -1567,10 +1575,14 @@ gnus-score-headers
                            (gnus-message
                             7 "Scoring on headers or body skipped.")
                            nil)
+                       ;; Run score-fn
+                       (if (eq header 'score-fn)
+                           (setq new (gnus-score-func scores trace))
                        ;; Call the scoring function for this type of "header".
                        (setq new (funcall (nth 2 entry) scores header
-                                          now expire trace)))
+                                          now expire trace))))
                  (push new news))))
+
            (when (gnus-buffer-live-p gnus-summary-buffer)
              (let ((scored gnus-newsgroup-scored))
                (with-current-buffer gnus-summary-buffer
@@ -1636,6 +1648,35 @@ gnus-score-orphans
                 (not (string= id "")))
        (gnus-score-lower-thread thread score)))))
 
+(declare-function cl-pairlis "cl-lib")
+
+(defun gnus-score-func (scores &optional trace)
+  (let (articles alist entries)
+    (while scores
+      (setq articles gnus-scores-articles
+           alist (car scores)
+           scores (cdr scores)
+           entries (assoc 'score-fn alist))
+      (dolist (score-fn (cdr entries))
+       (let ((score-fn (car score-fn))
+             article-alist score fn-score)
+         (dolist (art articles)
+           (setq article-alist
+                 (cl-pairlis
+                  '(number subject from date id
+                           refs chars lines xref extra)
+                  (car art))
+                 score (cdr art))
+           (if (integerp (setq fn-score (funcall score-fn
+                                                 article-alist score)))
+               (setcdr art (+ score fn-score)))
+           (setq score (cdr art))
+           (when trace
+             (if (integerp fn-score)
+                 (push (cons (car-safe (rassq alist gnus-score-cache))
+                             (list score-fn fn-score))
+                       gnus-score-trace)))))))))
+
 (defun gnus-score-integer (scores header now expire &optional trace)
   (let ((gnus-score-index (nth 1 (assoc header gnus-header-index)))
        entries alist)

-- 
Alex. <abochannek@google.com>