João Távora <joaotavora@gmail.com> writes:

> Beatrix Klebe <beeuhtricks@gmail.com> writes:
>
>> I know how to do hotpaches but that doesn't appear to solve the
>> problem I'm having here, unless I've missed something. The problem is
>> with moving the opening bracket, not the insertion point.
>
> Beatrix,
>
> I think you may have missed the fact that I am suggesting alternatives
> that:
>
> * involve cc-mode, or one of its derived modes;
>
> * don't involve M-x c-toggle-auto-newline (turning on what you call
>   auto-newline-mode);
>
> * involve turning on the global electric-layout-mode and a thin
>   customization for it in the buffers where you think it's relevant
>   (presumably cc-mode);
>
> * may involve multiple fixed/patched versions of lisp/electric.el as I
>   understand your problem(s);
>
> As it stands, the last patch I sent you passes my only test which is
> this:  given a file 33794.el which is just:
>
>    (electric-pair-mode)
>    (electric-layout-mode)
>     
>    (add-hook 'c-mode-hook
>              (lambda ()
>                (setq-local electric-layout-rules
>                            '((?\{ . after)
>                              (?\{ . after-stay)))))
>
>
> then running this from a shell:
>
>    $ emacs -Q -l 33794.el something.c
>
> Opens a new c-mode buffer.  Type 'int main ()' and then an opening
> brace.  You should get:
>
>    int main () {
>        <cursor>
>    }
>
> Can you reproduce these results?  If you can come up with more of these
> tests written in this or a similarly simple and exact manner it's easier
> for me to understand what's going on (it's also easier to write
> automated tests).
>
> João
>
>>
>>
>> On Fri, Dec 21, 2018 at 2:20 PM João Távora <joaotavora@gmail.com> wrote:
>>>
>>> Hi Beatrix,
>>>
>>> The solution I propose involves introducing the hotpatch I attached
>>> to fix electric-layout-mode in your emacs, so I wouldn't expect it
>>> to work if you haven't done that.
>>>
>>> Do you know how to do it?
>>>
>>> Though Alan will probably suggest otherwise, I'd also steer away
>>> from c-specific functionality and keep to the triad
>>> electric-indent-mode, electric-pair-mode and electric-indent-mode,
>>> at least while we try to extend/fix these modes to accommodate your
>>> needs.
>>>
>>> After such a solution is evaluated, you can select to keep it or move to something else.
>>>
>>> João
>>>
>>> On Fri, Dec 21, 2018, 19:06 Beatrix Klebe <beeuhtricks@gmail.com wrote:
>>>>
>>>> Here's the link, I believe it was Stefan that answered it:
>>>> https://emacs.stackexchange.com/questions/2837/automatically-formatting-brackets/2853#2853
>>>>
>>>> I have tried this with emacs -Q and it does not fix the issue, which
>>>> is as follows.
>>>>
>>>> Ordinarily in cc-mode when you have auto-newline-mode activated, and
>>>> as far as I can tell, a cc-mode configuration that supports it, (which
>>>> csharp-mode contains), the following happens when opening a block
>>>> (pipe is the cursor):
>>>>
>>>> void Main() {| // opening bracket is typed
>>>>
>>>> becomes
>>>>
>>>> void Main
>>>> {
>>>>     |
>>>>
>>>> when c-toggle-auto-newline is activated. However, if you also want
>>>> your braces automatically paired, with electric-pair-mode, instead the
>>>> following occurs:
>>>>
>>>> void Main() {| // opening bracket is typed
>>>>
>>>> void Main() {|} // electric-pair-mode closes the open bracket, but
>>>> auto-newline-mode does not appear to do anything.
>>>>
>>>> void Main() {
>>>>     |
>>>> } // user hits return, inserting the cursor at the correct indent
>>>> level, but leaving the opening brace where it is.
>>>>
>>>> The ideal/desired behavior is:
>>>>
>>>> void Main() {| // opening bracket is typed
>>>>
>>>> void Main()
>>>> {
>>>>     |
>>>> } // user hits return key, electric-pair-mode pairs up the brackets,
>>>> and auto-newline-mode formats the braces correctly
>>>>
>>>> It would also probably suffice to format with the newline before
>>>> hitting enter as well, although I think I prefer hitting enter to open
>>>> the block. I'm quite curious as to the internals of these formatting
>>>> systems and would be happy to help with a fix/feature if that would be
>>>> desired, I am mostly an OCaml programmer but C# is my day job and I've
>>>> just recently gotten deeper into Emacs Lisp.
>>>>
>>>> On Fri, Dec 21, 2018 at 1:49 PM João Távora <joaotavora@gmail.com> wrote:
>>>> >
>>>> > Beatrix Klebe <beeuhtricks@gmail.com> writes:
>>>> >
>>>> > > I believe I saw your Stack Overflow answer about this while searching
>>>> > > for the solution. electric-layout-mode works with some quirks, such as
>>>> > > that if you put a space after parens in a function definition, the
>>>> > > space gets carried on to the newline with that method, which is a bit
>>>> > > annoying. What would be ideal, and what I'm looking for, is to get
>>>> > > auto-pairing of brackets with braces being placed where they should be
>>>> > > automatically and the insertion point getting put in between them at
>>>> > > the correct indent level, such as what happens with Visual Studio, or
>>>> > > Visual Studio Code, or several other editors with this functionality.
>>>> > > Perhaps it is not emacslike to have such behavior be totally
>>>> > > automated, but I am used to it and finds it decreases my ordinary
>>>> > > levels of frustration when working with verbose and imperative
>>>> > > languages. I am currently trying to write some insert specifiers for
>>>> > > smartparens to do this, but it is proving more difficult to find an
>>>> > > elegant solution than I had expected.
>>>> >
>>>> > It is quite emacslike (though maybe not activated by default): you just
>>>> > have to report the bugs to the Emacs developers as efficiently as
>>>> > possible.
>>>> >
>>>> > 1. Though Alan possibly has already, I still cannot understand the
>>>> >    original problem.  Can you start by describing what the buffer looked
>>>> >    like before, what you did, what it looked like afterwards, and what
>>>> >    you expected it to look like?  If possible start with a clean Emacs
>>>> >    -Q recpe.
>>>> >
>>>> > 2. I have experimented with nicer-playing like alternatives like
>>>> >    electric-layout-mode.  I came across a few quirks myself (though I'm
>>>> >    not sure if they are the same as yours). So I prepared a patch (in
>>>> >    branch scratch/fix-33794-extend-electric-layout-mode) and attached
>>>> >    it after the sig.
>>>> >
>>>> > After loading this patch, in a simple Emacs -Q the configuration:
>>>> >
>>>> >    (electric-pair-mode)
>>>> >    (electric-layout-mode)
>>>> >
>>>> >    (add-hook 'c-mode-hook
>>>> >           (lambda ()
>>>> >             (setq-local electric-layout-rules
>>>> >                         '((?\{ . after)
>>>> >                           (?\{ . after-stay)))))
>>>> >
>>>> > And, when visiting a C file, if I press `{' I get the expected
>>>> > pair+layout+indent behaviour.  Sor example opening a brace after
>>>> > int main () gives me:
>>>> >
>>>> >     int main () {
>>>> >         <cursor here>
>>>> >     }
>>>> >
>>>> > I, like Stefan, think cc-mode could/should set electric-layout-rules
>>>> > buffer-locally to reflect whatever c-style the user has selected.
>>>> >
>>>> > Thanks,
>>>> > João
>>>> >
>>>> > PS: Also, can you link to the the relevant to the stack overflow answer you
>>>> > mentioned?
>>>> >
>>>> > commit ab036bdedbb49ecc96d550b5e883e43bb03eaccc
>>>> > Author: João Távora <joaotavora@gmail.com>
>>>> > Date:   Fri Dec 21 18:00:08 2018 +0000
>>>> >
>>>> >     Extend electric-layout-mode to handle more complex layouts
>>>> >
>>>> >     Also, have it play nice with electric-pair-mode.
>>>> >
>>>> >     Multiple matching entries in `electric-layout-rules' are executed in
>>>> >     order of appearance.  When inserting a newline in the 'after-stay
>>>> >     rule, ensure electric-pair-open-newline-between-pairs is nil.
>>>> >
>>>> >     Arguably the logic behind electric-pair-open-newline-between-pairs
>>>> >     should be moved to electric-layout-mode, but the current rule-matching
>>>> >     engine doesn't allow for it.  The current solution seems to be good
>>>> >     enough for the situations reported in bug#33794.
>>>> >
>>>> >     * lisp/electric.el (electric-layout-rules): Adjust docstring.
>>>> >     (electric-layout-post-self-insert-function): Loop through rules.  Bind
>>>> >     electric-pair-open-newline-between-pairs to nil when handling
>>>> >     after-stay.
>>>> >
>>>> > diff --git a/lisp/electric.el b/lisp/electric.el
>>>> > index 6dbf46b80c..6a307a49b9 100644
>>>> > --- a/lisp/electric.el
>>>> > +++ b/lisp/electric.el
>>>> > @@ -370,38 +370,43 @@ electric-layout-rules
>>>> >
>>>> >  The symbols specify where in relation to CHAR the newline
>>>> >  character(s) should be inserted. `after-stay' means insert a
>>>> > -newline after CHAR but stay in the same place.")
>>>> > +newline after CHAR but stay in the same place.
>>>> > +
>>>> > +If multiple rules match, they are all executed in order of
>>>> > +appearance.")
>>>> >
>>>> >  (defun electric-layout-post-self-insert-function ()
>>>> > -  (let* ((rule (cdr (assq last-command-event electric-layout-rules)))
>>>> > -         pos)
>>>> > -    (when (and rule
>>>> > -               (setq pos (electric--after-char-pos))
>>>> > +  (let (pos)
>>>> > +    (when (and (setq pos (electric--after-char-pos))
>>>> >                 ;; Not in a string or comment.
>>>> >                 (not (nth 8 (save-excursion (syntax-ppss pos)))))
>>>> > -      (let ((end (point-marker))
>>>> > -            (sym (if (functionp rule) (funcall rule) rule)))
>>>> > -        (set-marker-insertion-type end (not (eq sym 'after-stay)))
>>>> > -        (goto-char pos)
>>>> > -        (pcase sym
>>>> > -          ;; FIXME: we used `newline' down here which called
>>>> > -          ;; self-insert-command and ran post-self-insert-hook recursively.
>>>> > -          ;; It happened to make electric-indent-mode work automatically with
>>>> > -          ;; electric-layout-mode (at the cost of re-indenting lines
>>>> > -          ;; multiple times), but I'm not sure it's what we want.
>>>> > -          ;;
>>>> > -          ;; FIXME: check eolp before inserting \n?
>>>> > -          ('before (goto-char (1- pos)) (skip-chars-backward " \t")
>>>> > -                   (unless (bolp) (insert "\n")))
>>>> > -          ('after  (insert "\n"))
>>>> > -          ('after-stay (save-excursion
>>>> > -                         (let ((electric-layout-rules nil))
>>>> > -                           (newline 1 t))))
>>>> > -          ('around (save-excursion
>>>> > -                     (goto-char (1- pos)) (skip-chars-backward " \t")
>>>> > -                     (unless (bolp) (insert "\n")))
>>>> > -                   (insert "\n")))      ; FIXME: check eolp before inserting \n?
>>>> > -        (goto-char end)))))
>>>> > +      (goto-char pos)
>>>> > +      (dolist (rule electric-layout-rules)
>>>> > +        (when (eq last-command-event (car rule))
>>>> > +          (let* ((end (point-marker))
>>>> > +                 (rule (cdr rule))
>>>> > +                 (sym (if (functionp rule) (funcall rule) rule)))
>>>> > +            (set-marker-insertion-type end (not (eq sym 'after-stay)))
>>>> > +            (pcase sym
>>>> > +              ;; FIXME: we used `newline' down here which called
>>>> > +              ;; self-insert-command and ran post-self-insert-hook recursively.
>>>> > +              ;; It happened to make electric-indent-mode work automatically with
>>>> > +              ;; electric-layout-mode (at the cost of re-indenting lines
>>>> > +              ;; multiple times), but I'm not sure it's what we want.
>>>> > +              ;;
>>>> > +              ;; FIXME: check eolp before inserting \n?
>>>> > +              ('before (goto-char (1- pos)) (skip-chars-backward " \t")
>>>> > +                       (unless (bolp) (insert "\n")))
>>>> > +              ('after  (insert "\n"))
>>>> > +              ('after-stay (save-excursion
>>>> > +                             (let ((electric-layout-rules nil)
>>>> > +                                   (electric-pair-open-newline-between-pairs nil))
>>>> > +                               (newline 1 t))))
>>>> > +              ('around (save-excursion
>>>> > +                         (goto-char (1- pos)) (skip-chars-backward " \t")
>>>> > +                         (unless (bolp) (insert "\n")))
>>>> > +                       (insert "\n")))      ; FIXME: check eolp before inserting \n?
>>>> > +            (goto-char end)))))))
>>>> >
>>>> >  (put 'electric-layout-post-self-insert-function 'priority  40)
>>>> >