How do I add support for Shift+Space to insert half-spaces?

[NightMachinery]

I know there are workarounds implemented:

 ("B" ?\u200C)     ;; ZWNJ -- ZERO WIDTH NON-JOINER  فاصلهٔ مجازى

But I like to keep my muscle memory and press shift+space. Is it possible to do this?

[NightMachinery]

My current workaround:

(defun night/insert-persian-half-space ()
  "Insert a Persian half-space (zero-width non-joiner) character."
  (interactive)
  (insert-char ?\u200C))

(defun night/insert-shift-space ()
  (interactive)
  (cond
   ((string= current-input-method "farsi-isiri-9147")
    (night/insert-persian-half-space))
   (t
    (insert-char ?\s)
    ;; It'd be best if we could do shift+space from the original map, e.g., [help:org-self-insert-command], [help:lispy-space], but I don't know how to do that.
    ;; It still doesn't matter much, as we never use shift+space in non-Persian buffers anyway.
    )))

;; `map!' needs Doom.
(map!
 :i
 "S-SPC" #'night/insert-shift-space
 )

[mohsenBanan]

Salaam Feraidoon, @NightMachinery . Sorry about the delay in responding. I just did not see your note until just now. What you have done is a fine solution for yourself. We can't do a S-SPC in quail-define-rules. So, it has to be done outside of there. As a general solution, the mapping should not be global. I can create a minor mode with a keymap that includes the S-SPC. Then we could add that to selection of the input method, optionally and accomplish S-SPC mapping. I myself don't use isiri-9147 and did not know about the importance of S-SPC. Is this something that would be highly desired by most isiri-9147 users?

[NightMachinery]

@mohsenBanan Hi, thanks! I don't quite get how the minor mode solution would work, but, yes, half-spaces are very important in writing Persian correctly. I think adding a built-in workaround for inserting half-spaces is worth the additional complexity.