bug#70846: Imenu flatten

[Juri Linkov <juri@linkov.net>]

>> >> >> >> BTW, the manual says in (info "(emacs) Imenu"):
>> >> >> >>
>> >> >> >>      You can customize the way the menus are sorted by setting the
>> >> >> >>   variable ‘imenu-sort-function’.  By default, names are ordered as they
>> >> >> >>   occur in the buffer; if you want alphabetic sorting, use the symbol
>> >> >> >>   ‘imenu--sort-by-name’ as the value.  You can also define your own
>> >> >> >>   comparison function by writing Lisp code.
>> >> >>
>> >> >> The "menus" above are pertaining only to popup menus,
>> >> >> and the variable ‘imenu-sort-function’ can't be used
>> >> >> to change the sorting order of Imenu completion candidates.
>> >> >> Only the following customization changes this order:
>> >> >>
>> >> >>   (add-to-list 'completion-category-overrides
>> >> >>                '(imenu (display-sort-function . identity)))
>> >> >>
>> >> >> Using this setting is especially essential for Imenu
>> >> >> on a PDF document with doc-view.el to keep the order
>> >> >> of chapters for the table of contents.
>> >> >>
>> >> >> But I have no idea how to document this customization.
>> >> >
>> >> > Now I'm confused: I thought the change you installed was supposed to
>> >> > make sure the completion candidates are sorted using the same sort
>> >> > order as determined by imenu-sort-function.  If not, then what did
>> >> > your change do in this matter?
>> >>
>> >> Completions can be sorted only by 'display-sort-function'.
>> >> There is no other way to sort completions.
>> >
>> > Then what did the change you installed do wrt sorting of candidates?
>>
>> It allows the users to customize the sorting order of
>> completion candidates displayed by 'imenu'.
>
> And the only way to customize that is via add-to-list as above?  IOW,
> without the change you installed, even the add-to-list method would
> not have worked?

Yes, there was no way to customize sorting of Imenu completion candidates.

Ok, I could add display-sort-function directly to the imenu completing-read
that will depend on the value of display-sort-function.  Then there will be
no need to change the manual.