Set gnus-simplify-subject-functions in group parameters?

Set gnus-simplify-subject-functions in group parameters?

[Tim Landscheidt]

Hi,

I receive watchlist notifications from Wikipedia and sort
them into a group.  I want to thread them by page, i. e.:

|    [  35: Wikipedia              ] Wikipedia-Seite Diskussion:Lasithi-Hochebene wurde von Langläufer erstellt
|    [  41: Wikipedia              ] Wikipedia-Seite Lasithi-Hochebene wurde von Langläufer geändert
|    [  40: Wikipedia              ] Wikipedia-Seite Lasithi wurde von Langläufer geändert

should be displayed as:

|    [  35: Wikipedia              ] Wikipedia-Seite Diskussion:Lasithi-Hochebene wurde von Langläufer erstellt
|        <  41: Wikipedia              > Wikipedia-Seite Lasithi-Hochebene wurde von Langläufer geändert
|    [  40: Wikipedia              ] Wikipedia-Seite Lasithi wurde von Langläufer geändert

I read "Customizing Threading", thought
gnus-simplify-subject-functions would be a good idea,
created a function for testing and set the group parameters
to:

| ((auto-expire . t)
|  (gnus-simplify-subject-functions
|   (tl-watchlist-subject-munger)))

But when I enter the group, the function is not called.
edebug showed that gnus-gather-threads-by-subject is called,
but gnus-simplify-subject-functions's value there is (the
default) (gnus-simplify-subject-re
gnus-simplify-whitespace).

How can I set gnus-simplify-subject-functions for a group to
a different value?

TIA,
Tim

Re: Set gnus-simplify-subject-functions in group parameters?

[Katsumi Yamaoka]

Er, first of all, does `gnus-simplify-subject-functions' really
work?  I tried this,

(setq gnus-simplify-subject-functions '(gnus-simplify-subject-re))

and confirmed that `gnus-simplify-subject-re' runs.  However I
can still see "Re: "s in the summary lines. :(

On Thu, 23 Feb 2017 13:51:02 +0000, Tim Landscheidt wrote:
> How can I set gnus-simplify-subject-functions for a group to
> a different value?

If it works, something like the following will probably work:

--8<---------------cut here---------------start------------->8---
(defun my-gnus-simplify-subject ()
  (setq gnus-simplify-subject-functions
	(cond ((string-equal "nnfolder:foo.bar" gnus-newsgroup-name)
	       '(tl-watchlist-subject-munger))
	      ((string-match "\\`nnimap:foo\\." gnus-newsgroup-name)
	       '(tl-subject-filter-2))
	      (t nil))))

(add-hook 'gnus-select-group-hook 'my-gnus-simplify-subject)
--8<---------------cut here---------------end--------------->8---

(string-equal "nnfolder:foo.bar" ...) matches the group.
(string-match "\\`nnimap:foo\\." ...) matches the groups of which
the group names begin with "nnimap:foo." .
The last (t nil) must be there.

Unfortunately Gnus isn't designed assuming
`gnus-simplify-subject-functions' to be a group parameter, IIUC.

Re: Set gnus-simplify-subject-functions in group parameters?

[Andreas Schwab]

On Feb 24 2017, Katsumi Yamaoka <yamaoka@jpl.org> wrote:

> The last (t nil) must be there.

Does it?  If no condition succeeds, cond returns nil.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: Set gnus-simplify-subject-functions in group parameters?

[Reiner Steib]

On Fri, Feb 24 2017, Katsumi Yamaoka wrote:

> Er, first of all, does `gnus-simplify-subject-functions' really
> work?  I tried this,
> (setq gnus-simplify-subject-functions '(gnus-simplify-subject-re))
> and confirmed that `gnus-simplify-subject-re' runs.  However I
> can still see "Re: "s in the summary lines. :(

I guess `gnus-simplify-subject-functions' is used for threading and
scoring and doesn't influence the display (in summary and article
buffers).  For the latter, `gnus-list-identifiers' might be useful.

With the following code, I can see that the function rs-test is called
twice for each article (after turning on threading):

| Generating summary...done
| No more unseen articles
| No more unread articles
| SIMPLIFY: subdomain adressing
| SIMPLIFY: Test-von-Reiner
| Generating summary...
| SIMPLIFY: subdomain adressing
| SIMPLIFY: Test-von-Reiner
| Generating summary...done
| Threading is now on

(defun rs-test (s) (message "SIMPLIFY: %s" s))
(setq
 gnus-parameters
 `(;; ...
   ("misc\\.test"
    (gnus-simplify-subject-functions
     '(gnus-simplify-subject-re
       gnus-simplify-whitespace
       rs-test))
    (gnus-summary-line-format "..."))
  ...))

Bye, Reiner.

Re: Set gnus-simplify-subject-functions in group parameters?

[Katsumi Yamaoka]

Thanks a lot Andreas and Reiner.  So, Tim, what you want to use
would probably be `gnus-list-identifiers', I guess.  Note that
if it is a regexp, the one atutually used is:

(concat "^\\(?:R[Ee]: +\\)*\\(" regexp " *\\)")

cf. `gnus-summary-remove-list-identifiers'

You can use one of the following ways (all I confirmed):

;; Set it globally:
(setq gnus-list-identifiers "Wikipedia-Seite")

;; Set it per group (use `gnus-parameters'):
(add-to-list
 'gnus-parameters
 '("\\`nnxx:foo\\.bar\\'"
   (gnus-list-identifiers "Wikipedia-Seite")))

;; Set it per group (use the `G c' buffer):
[X] Identifier: [Value Menu] Regexp: Wikipedia-Seite
    If non-nil, specify how to remove ‘identifiers’ from articles’ subject. More

Re: Set gnus-simplify-subject-functions in group parameters?

[Tim Landscheidt]

Reiner Steib <reinersteib+gmane@imap.cc> wrote:

>> Er, first of all, does `gnus-simplify-subject-functions' really
>> work?  I tried this,
>> (setq gnus-simplify-subject-functions '(gnus-simplify-subject-re))
>> and confirmed that `gnus-simplify-subject-re' runs.  However I
>> can still see "Re: "s in the summary lines. :(

> I guess `gnus-simplify-subject-functions' is used for threading and
> scoring and doesn't influence the display (in summary and article
> buffers).  For the latter, `gnus-list-identifiers' might be useful.

Yes, and I do not want to change the display, but just group
together articles that refer to the same "topic".

> With the following code, I can see that the function rs-test is called
> twice for each article (after turning on threading):

> | Generating summary...done
> | No more unseen articles
> | No more unread articles
> | SIMPLIFY: subdomain adressing
> | SIMPLIFY: Test-von-Reiner
> | Generating summary...
> | SIMPLIFY: subdomain adressing
> | SIMPLIFY: Test-von-Reiner
> | Generating summary...done
> | Threading is now on

> (defun rs-test (s) (message "SIMPLIFY: %s" s))
> (setq
>  gnus-parameters
>  `(;; ...
>    ("misc\\.test"
>     (gnus-simplify-subject-functions
>      '(gnus-simplify-subject-re
>        gnus-simplify-whitespace
>        rs-test))
>     (gnus-summary-line-format "..."))
>   ...))

I cannot reproduce this with Gnus v5.13 (GNU Emacs 25.1.1).
If I set:

| (setq gnus-parameters
|       '(("^mail\\.wikipedia\\.watchlist\\.dewiki$"
|          (gnus-thread-sort-functions '(gnus-thread-sort-by-subject)))))

gnus-thread-sort-functions is gnus-thread-sort-by-subject in
the summary buffer (and the sorting is changed from the de-
fault), so the parameters are read.  If I set:

| (setq gnus-parameters
|       '(("^mail\\.wikipedia\\.watchlist\\.dewiki$"
|          (gnus-simplify-subject-functions
|           '(gnus-simplify-subject-re
|             gnus-simplify-whitespace
|             rs-test)))))

(and gnus-verbose to 99), when entering the group *Messages*
only says:

| Retrieving newsgroup: mail.wikipedia.watchlist.dewiki...
| Fetching headers for mail.wikipedia.watchlist.dewiki...done
| Scoring...done
| Sorting threads...done
| Generating summary...done

and gnus-simplify-subject-functions is still
'(gnus-simplify-subject-re gnus-simplify-whitespace).

Tim

Re: Set gnus-simplify-subject-functions in group parameters?

[Tim Landscheidt]

Katsumi Yamaoka <yamaoka@jpl.org> wrote:

> […]

>> How can I set gnus-simplify-subject-functions for a group to
>> a different value?

> If it works, something like the following will probably work:

> (defun my-gnus-simplify-subject ()
>   (setq gnus-simplify-subject-functions
> 	(cond ((string-equal "nnfolder:foo.bar" gnus-newsgroup-name)
> 	       '(tl-watchlist-subject-munger))
> 	      ((string-match "\\`nnimap:foo\\." gnus-newsgroup-name)
> 	       '(tl-subject-filter-2))
> 	      (t nil))))

> (add-hook 'gnus-select-group-hook 'my-gnus-simplify-subject)

> (string-equal "nnfolder:foo.bar" ...) matches the group.
> (string-match "\\`nnimap:foo\\." ...) matches the groups of which
> the group names begin with "nnimap:foo." .
> The last (t nil) must be there.

Thanks, I'll try (something like) that.

> Unfortunately Gnus isn't designed assuming
> `gnus-simplify-subject-functions' to be a group parameter, IIUC.

What is the difference between "good" and "bad" group para-
meters in Lisp?  I. e., why does gnus-thread-sort-functions
work, but gnus-simplify-subject-functions does not?

Tim

Re: Set gnus-simplify-subject-functions in group parameters?

[Tim Landscheidt]

I wrote:

> […]

> Thanks, I'll try (something like) that.

> […]

I found that the solution with
gnus-simplify-subject-functions does not meet my use case; I
wanted:

|    [  35: Wikipedia              ] Wikipedia-Seite Diskussion:Lasithi-Hochebene wurde von Langläufer erstellt
|    [  41: Wikipedia              ] Wikipedia-Seite Lasithi-Hochebene wurde von Langläufer geändert
|    [  40: Wikipedia              ] Wikipedia-Seite Lasithi wurde von Langläufer geändert

to be displayed as:

|    [  35: Wikipedia              ] Wikipedia-Seite Diskussion:Lasithi-Hochebene wurde von Langläufer erstellt
|        <  41: Wikipedia              > Wikipedia-Seite Lasithi-Hochebene wurde von Langläufer geändert
|    [  40: Wikipedia              ] Wikipedia-Seite Lasithi wurde von Langläufer geändert

However, with gnus-simplify-subject-functions munging the
subject, I ended up with (IIRC, did not record it):

|    [  35: Wikipedia              ] Wikipedia-Seite Diskussion:Lasithi-Hochebene wurde von Langläufer erstellt
|        [  41: Wikipedia              ]
|    [  40: Wikipedia              ] Wikipedia-Seite Lasithi wurde von Langläufer geändert

i. e. the different subjects were not displayed.  So I
looked a bit more at the threading code and viewed my prob-
lem as the addition of a reference to a fake thread root
"Wikipedia page Lasithi-Hochebene".  I set the group parame-
ters to:

| ((gnus-alter-header-function
|   (lambda
|     (header)
|     (let*
|         ((references
|           (mail-header-references header))
|          (subject
|           (mail-header-subject header))
|          (reference-to-add
|           (cond
|            ((string-match "^Wikipedia-Seite \\(Benutzer\\|Hilfe\\|Kategorie\\|Portal\\|Vorlage\\|Wikipedia\\)\\(?: Diskussion\\)?:\\(.*\\) wurde von .* \\(?:erstellt\\|geändert\\|gelöscht\\)$" subject)
|             (concat
|              (match-string 1 subject)
|              ":"
|              (match-string 2 subject)))
|            ((string-match "^Wikipedia-Seite \\(?:Diskussion:\\)?\\(.*\\) wurde von .* \\(?:erstellt\\|geändert\\|gelöscht\\)$" subject)
|             (match-string 1 subject)))))
|       (if reference-to-add
|           (let
|               ((encoded-reference-to-add
|                 (concat "<"
|                         (base64-encode-string reference-to-add t)
|                         "@de.wikipedia.org>")))
|             (mail-header-set-references header
|                                         (if
|                                             (string-equal "" references)
|                                             encoded-reference-to-add
|                                           (concat references " " encoded-reference-to-add))))))))
|  (gnus-summary-thread-gathering-function
|   (lambda
|     (threads)
|     (gnus-gather-threads-by-references threads))))

It is currently not possible to directly set
gnus-summary-thread-gathering-function to
gnus-gather-threads-by-references due to
https://debbugs.gnu.org/26105, so the latter setting works
around for that.

The function for gnus-alter-header-function should be easy
to understand; encoding the page title in Base64 is probably
overly cautious and careless at the same time (is "=" legal
in message IDs?), but it works for me so far.

After a long session with edebug, I also added:

| (setq gnus-newsgroup-variables '(gnus-alter-header-function))

to my ~/.emacs.  This is necessary because
gnus-get-newsgroup-headers-xover calls gnus-nov-parse-line
(which calls gnus-alter-header-function) framed by:

| […]
|     (with-current-buffer nntp-server-buffer
| […]

Without gnus-newsgroup-variables the group parameters are
only set for the summary buffer, so
gnus-alter-header-function would be always nil (or whatever
the global value is).

HTH,
Tim