Vertical Split

[manueldeljesus]

Is there any way to make the REPL open in a vertical split? So that one may have the editor on the left-hand side of the screen and the REPL on the right-hand side.

[tpapp]

julia-repl does not do anything special here, just try the global emacs settings, eg see customizations here, or questions similar to this one. That said, I always found it finicky. See also https://www.emacswiki.org/emacs/ToggleWindowSplit.

[wentasah]

I think that display actions are what you need:

(add-to-list 'display-buffer-alist
             '("\\*julia\\*" (display-buffer-reuse-window display-buffer-in-direction)
           (direction . right)))

[manueldeljesus]

I have been checking the references that @tpapp proposed, but I have not been able to make them work. Display actions look promising, but your code does not seem to work for me.

I have been reading a bit the code, and I have understood -may be wrong- that julia-repl forces the REPL window to open in the bottom part of the frame, am I right? Shouldn't I need to change the function that calls the REPL? Or this is what display actions do? Changing the behavior established by default?

I apologize in advance if what I am asking is so basic. I am always having a hard time wrapping my head around Elisp concepts.

[manueldeljesus]

After several more tests, I have observed that the code works but only if I load it once I have my julia file opened. It looks like I am not configuring display-buffer-alist in the correct moment in my initial config file. Am I assuming correctly that I should add the display action after the julia-repl package has loaded?

[tpapp]

julia-repl forces the REPL window to open in the bottom part of the frame, am I right?

I don't think so. We use pop-to-buffer.

That said, we should be able to specify an action that is passed to display-buffer.

[tpapp]

You can experiment with this by modifying the line pop-to-buffer line in julia-repl --- just add an action you like. If you find one that helps, tell me and I will add a customizable option.

[manueldeljesus]

So far I believe that the problem that I am experiencing is that display-buffer-alist is being modified after my configuration modifies it, and for some reason my modification is being lost somewhere.

I will give an eye to the pop-to-buffer line as you suggest. I will let you know if I get to make it work somehow.

Thanks for the feedback.

[manueldeljesus]

After many tests (it must be said that a noob with respect to Emacs Lisp, so most of the tests may have been absurd to begin with), I can confirm that @wentasah 's code works, so I imagine that the action is well defined and has the intended result.

However, I cannot, for the life of me, pass the action to pop-to-buffer without it complaining or without it having no effect whatsoever. What format should the action have?

What I have been trying that does not work is this:

(pop-to-buffer inferior-buffer ((display-buffer-reuse-window display-buffer-in-direction) (direction . right)))

and some other variations, quoting some parts of the action and such. What may I be missing?

[wentasah]

This works for me:

(pop-to-buffer inferior-buffer '((display-buffer-reuse-window display-buffer-in-direction) (direction . right)))))

Note that actions specified in display-buffer-alist have higher priority than actions passed to pop-to-buffer and similar functions. So the above action will be ignored if display-buffer-alist contains some entry similar to what I posted above.

[manueldeljesus]

I believe that I tried that also and it didn't work, BUT it may have been because of the precedence that you refer to about display-buffer-alist.

The problem may then be with my configuration, that somehow display-buffer-alist is being redefined after I set the value that I want for it. I have already opened a question in Doom Emacs' Discord. Indeed, when I open a julia file, display-buffer-alist gets populated with a julia entry that is not the one that I defined and that set the opening position to bottom.

Thank you very much for your help. I will try to see if I can fix this with Doom. I will let you know if I reach any conclusion.

[manueldeljesus]

It seems that a critical piece of information about the problem was that I was using Doom Emacs, which uses some packages (within the popup module) to simplify the configuration of popup windows. This makes directly dealing with display-buffer-alistalmost impossible.

The solution to my problem was then to include the following code in my config.el:

(after! julia-repl
  (set-popup-rule! "^\\*julia:*.*\\*$" :quit nil :side 'right :width .5)
  )

With this configuration, the display action gets properly added to display-buffer-alist on top of the default one -that was forcing the appearance on the bottom-, and the REPL opens on the right-hand side of the window, occupying 50% of the width.

Again, thank you very much for your help. I hope that this answer serves to other Doom Emacs users.

[manueldeljesus]

Since I provided an explanation for the issue, and since alternatives solutions were provided, I believe that the issue can be closed without any problem.

Again, thank you very much for your help.