Best way to send an arbitrary sequence of key presses to an X window?

[BettaGeorge]

Sometimes I would like to insert text into an input field in an X application, which is of course not possible (okay, there is a shared clipboard, but that is not sufficient). However, if I could send raw key presses to the currently selected window, I could essentially make LISP type out my text for me. Clearly sending key presses to windows is possible (both exwm-input-send-next-key and simulation keys exist), so is there a way to tell EXWM to just take a sequence (a string) and send them in quick succession?
Obviously I could programmatically define simulation keys to do this, but if I want to be able to insert arbitrary strings, that would very quickly fill up the available disk space in the universe.
Edit: Github does not like org formatting.

[BettaGeorge]

I am going to answer my own question, but if anyone has a nicer way, I am all ears.

The following essentially accomplishes arbitrary string insertion into X windows:

  (defun exwm-send-string (str)
    "Takes a string and sends it (character by character) to the currently selected window if it is an X window."
    (if exwm-window-type
        (mapcar (lambda (char)
      		(exwm-input--fake-key (aref (read-kbd-macro (string char)) 0)))
  	      str
  	      )))

This is obviously horribly unsafe if you are not currently focusing some kind of text input. Just imagine the havoc this could wreak if you for some reason happen to have a graphical vim instance open in normal mode. But I do not believe it is possible to reliably figure out whether an X application currently thinks it has a text input, so this is probably best possible.

[QiangF]

Maybe you can use an input method. See sinic/autocharmode#1
But your function doesn't work for unicode chars. To send any string, we may also need the input method fcitx/fcitx5#1489

[BettaGeorge]

Oh, nice! I am indeed looking for a way to input Chinese characters, so I am going to have a look at that. I did not know that fcitx can distinguish whether we are in an input field! Do you know whether fcitx works reliably with different kinds of applications? Certain GTK versions tend to simply ignore my input method.
Do you use EXWM with a Chinese input method? If so, would you mind sharing your setup? Reasonable pinyin input would make my desktop so much better.

[QiangF]

fcitx5 has the best compatibility, I have not come across any issue.
But rime is more popular among chinese users, because it is cross platform.
I don't use pinyin. I think it is better to install fcitx5-rime plugin, and use a rime setting such as this
https://github.com/LIPiston/rime-ice