bug#51852: Gnus: Add User-Defined Spec example

bug#51852: Gnus: Add User-Defined Spec example

[積丹尼 Dan Jacobson]

(info "(gnus) Formatting Basics") says

   Also Gnus supports some extended format specifications, such as
‘%&user-date;’.

OK, please say what user-date is, and list the rest.

Wait, on (info "(gnus) User-Defined Specs") we see it is something we
create ourselves. So on (info "(gnus) Formatting Basics") the "foo"
example should be used, and not "user-date".

And mainly, on (info "(gnus) User-Defined Specs") there is no example of
how to make a User-Defined Spec. E.g., how to continue the example on
(info "(gnus) Advanced Formatting") to finally get 96/08/09 .

By the way, that (info "(gnus) Advanced Formatting") example,

       Let’s take an example.  The ‘%o’ spec in the summary mode lines will
    return a date in compact ISO8601 format—‘19960809T230410’.  This is
    quite a mouthful, so we want to shave off the century number and the
    time, leaving us with a six-character date.  That would be ‘%~(cut-left
    2)~(max-right 6)~(pad 6)o’.  (Cutting is done before maxing, and we need
    the padding to ensure that the date is never less than 6 characters to
    make it look nice in columns.)

is bad programming: not Y10K proof.

bug#51852: Gnus: Add User-Defined Spec example

[Lars Ingebrigtsen]

積丹尼 Dan Jacobson <jidanni@jidanni.org> writes:

> (info "(gnus) Formatting Basics") says
>
>    Also Gnus supports some extended format specifications, such as
> ‘%&user-date;’.
>
> OK, please say what user-date is, and list the rest.

It's documented in the "Summary Buffer Lines" node:

@item &user-date;
Age sensitive date format.  Various date format is defined in
@code{gnus-user-date-format-alist}.

There is (currently) no rest to list.

> And mainly, on (info "(gnus) User-Defined Specs") there is no example of
> how to make a User-Defined Spec. E.g., how to continue the example on
> (info "(gnus) Advanced Formatting") to finally get 96/08/09 .

This seems sufficient?

---
All the specs allow for inserting user defined specifiers---@samp{u}.
The next character in the format string should be a letter.  Gnus
will call the function @code{gnus-user-format-function-}@samp{X}, where
@samp{X} is the letter following @samp{%u}.  The function will be passed
a single parameter---what the parameter means depends on what buffer
it's being called from.
---

So there doesn't seem to be anything here to do, and I'm closing this
bug report.  If you want help with using Gnus, then I suggest asking on
an Emacs help-oriented mailing list.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#51852: Gnus: Add User-Defined Spec example

[積丹尼 Dan Jacobson]

Yes you have an example of how to call the function, but
I'm saying you need to add at least one example of the function itself.
E.g., like on https://www.emacswiki.org/emacs/GnusFormatting#h5o-7