bug#45767: icomplete-in-buffer completion does not work with dabbrev-completion

bug#45767: icomplete-in-buffer completion does not work with dabbrev-completion

[simon254--- via Bug reports for GNU Emacs, the Swiss army knife of text editors]

emacs -Q
in *scratch* evaluate
(setq icomplete-in-buffer t)
(icomplete-mode t)

type:
asdf1
asdf2
asdf followed by C-M-/ (dabbrev-completion) 
-> default completion is invoked, not icomplete-mode


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bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Lars Ingebrigtsen]

simon254@mailbox.org writes:

> emacs -Q
> in *scratch* evaluate
> (setq icomplete-in-buffer t)
> (icomplete-mode t)
>
> type:
> asdf1
> asdf2
> asdf followed by C-M-/ (dabbrev-completion) 
> -> default completion is invoked, not icomplete-mode

(I'm going through old bug reports that unfortunately weren't resolved
at the time.)

I can reproduce this on the current trunk, too, but skimming the code,
I'm not quite sure how this is supposed to work.  I've added Stefan to
the CCs; it looks like he added the icomplete-in-buffer thing back in
2013.

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

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Lars Ingebrigtsen [2022-05-06 21:04:18] wrote:

> simon254@mailbox.org writes:
>
>> emacs -Q
>> in *scratch* evaluate
>> (setq icomplete-in-buffer t)
>> (icomplete-mode t)
>>
>> type:
>> asdf1
>> asdf2
>> asdf followed by C-M-/ (dabbrev-completion) 
>> -> default completion is invoked, not icomplete-mode
>
> (I'm going through old bug reports that unfortunately weren't resolved
> at the time.)
>
> I can reproduce this on the current trunk, too, but skimming the code,
> I'm not quite sure how this is supposed to work.  I've added Stefan to
> the CCs; it looks like he added the icomplete-in-buffer thing back in
> 2013.

The problem is that `icomplete-in-buffer` relies on
`completion-in-region-mode-predicate` being passed to
`completion-in-region` (this is needed so Icomplete can know when you've
finished the completion), which `completion-at-point` does but which
`dabbrev-completion` does not do, so `icomplete-in-buffer` is not used
when completing via `dabbrev-completion`.


        Stefan

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Lars Ingebrigtsen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> The problem is that `icomplete-in-buffer` relies on
> `completion-in-region-mode-predicate` being passed to
> `completion-in-region` (this is needed so Icomplete can know when you've
> finished the completion), which `completion-at-point` does but which
> `dabbrev-completion` does not do, so `icomplete-in-buffer` is not used
> when completing via `dabbrev-completion`.

I see.  I've now added this to the doc string on icomplete-in-buffer,
and since this is working as intended, I'm closing this bug report.

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

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Lars Ingebrigtsen [2022-05-07 12:16:16] wrote:
> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> The problem is that `icomplete-in-buffer` relies on
>> `completion-in-region-mode-predicate` being passed to
>> `completion-in-region` (this is needed so Icomplete can know when you've
>> finished the completion), which `completion-at-point` does but which
>> `dabbrev-completion` does not do, so `icomplete-in-buffer` is not used
>> when completing via `dabbrev-completion`.
> I see.  I've now added this to the doc string on icomplete-in-buffer,
> and since this is working as intended, I'm closing this bug report.

No, it's not working as intended: what I wrote just means that the
problem is in `dabbrev-completion` which shouldn't just call
`completion-in-region` as it does.  It should either do it within
a let-binding of `completion-in-region-mode-predicate` or with a call
to `completion-at-point` instead (which will take care to bind
`completion-in-region-mode-predicate`).

I just pushed a patch doing the latter (and providing a new
`dabbrev-capf` function).


        Stefan

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Lars Ingebrigtsen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> No, it's not working as intended: what I wrote just means that the
> problem is in `dabbrev-completion` which shouldn't just call
> `completion-in-region` as it does.  It should either do it within
> a let-binding of `completion-in-region-mode-predicate` or with a call
> to `completion-at-point` instead (which will take care to bind
> `completion-in-region-mode-predicate`).
>
> I just pushed a patch doing the latter (and providing a new
> `dabbrev-capf` function).

Ah; thanks.

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

bug#45768: bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Juri Linkov]

>> (setq icomplete-in-buffer t)
>> (icomplete-mode t)
>>
>> type:
>> asdf1
>> asdf2
>> asdf followed by C-M-/ (dabbrev-completion)
>> -> default completion is invoked, not icomplete-mode
>
> I can reproduce this on the current trunk, too, but skimming the code,
> I'm not quite sure how this is supposed to work.

Could you explain where do you see that icomplete-mode is not invoked?
Should it enable icomplete keys in the buffer?  Or there is some
visual difference before the fixes and after?

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Lars Ingebrigtsen]

Juri Linkov <juri@linkov.net> writes:

> Could you explain where do you see that icomplete-mode is not invoked?
> Should it enable icomplete keys in the buffer?  Or there is some
> visual difference before the fixes and after?

Stefan fixed this now, I think?

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

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Juri Linkov]

>> Could you explain where do you see that icomplete-mode is not invoked?
>> Should it enable icomplete keys in the buffer?  Or there is some
>> visual difference before the fixes and after?
>
> Stefan fixed this now, I think?

How do you see that it's fixed?

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Stefan Monnier via Bug reports for GNU Emacs, the Swiss army knife of text editors]

Juri Linkov [2022-05-09 21:41:13] wrote:
>>> Could you explain where do you see that icomplete-mode is not invoked?
>>> Should it enable icomplete keys in the buffer?  Or there is some
>>> visual difference before the fixes and after?
>> Stefan fixed this now, I think?
> How do you see that it's fixed?

Try the recipe given in the bug report.  You should see now that after
M-C-/ the possible completions get listed (in icomplete-mode style) on
the same line (via an overlay).

The `icomplete-in-buffer` functionality is very rough around the edges.
I only implemented it as a kind of "proof of concept".  I think things
like `corfu-mode` work much better (because they don't displace
existing text in the buffer, they are just drawn on top of it).
[ To be honest, in my memory (from when I wrote the code), the list was
  shown in the echo area rather than "inline".  ]


        Stefan

bug#45767: bug#45768: icomplete-mode does not provide in region completion for dabbrev-completion

[Juri Linkov]

> Try the recipe given in the bug report.  You should see now that after
> M-C-/ the possible completions get listed (in icomplete-mode style) on
> the same line (via an overlay).

Sorry, I temporarily removed these lines from `completion-at-point`:

              (completion-in-region-mode-predicate
               (lambda ()
                 ;; We're still in the same completion field.
                 (let ((newstart (car-safe (funcall hookfun))))
                   (and newstart (= newstart start)))))

to be able to use the new `minibuffer-next-completion`
(this puzzle is still unsolved).

> The `icomplete-in-buffer` functionality is very rough around the edges.
> I only implemented it as a kind of "proof of concept".  I think things
> like `corfu-mode` work much better (because they don't displace
> existing text in the buffer, they are just drawn on top of it).

Now `C-,` (icomplete-backward-completions) and `C-.` (icomplete-forward-completions)
work fine inline after `M-C-/`.  But typing `C-j` (icomplete-force-complete-and-exit)
erases the current buffer and replaces its contents with the selected completion.
Then it signals an error while trying to call `exit-minibuffer`.  It seems inline
completions need more work to be as smooth as in the minibuffer.

> [ To be honest, in my memory (from when I wrote the code), the list was
>   shown in the echo area rather than "inline".  ]

Maybe as an option inline completion could just activate the minibuffer
with initial input as a string under point from the original buffer.
This will allow to use normal completion in the minibuffer.  Then
exiting the minibuffer will replace the initial string with the string
returned from the minibuffer.