Send Nix code from Emacs to Kitty
I’m learning Nix by following this tutorial and taking notes using Org
Mode. I organized the notes with my thoughts and some code examples. Doom Emacs
provides a function +eval/send-region-to-repl to run code in a language’s REPL
buffer. It’s useful until multiple-line input comes, which prints like so:
nix-repl> let
first_name = "Yejun";
last_name = "Su";
in
{
full_name = "${first_name} ${last_name}";
}
let
first_name = "Yejun";
last_name = "Su";
in
{
full_name = "${first_name} ${last_name}";
}
{ full_name = "Yejun Su"; }
It appears that the input is also getting printed along with the result, which
isn’t expected. However, when I tried with nix repl in Kitty, I didn’t encounter
this problem. A viable solution that emerged is to send the Nix code from the
org-babel source block directly to the Nix REPL in Kitty.
Thanks to the Kitty’s remote control, it’s easy to advise the
+eval/send-region-to-repl function to send the Nix code to Kitty:
(defun kitty--ensure-nix-repl-tab ()
(unless (zerop (shell-command "kitty @ ls | grep -q '\"title\": \"nix-repl\"'"))
(shell-command "kitty @ launch --type tab --tab-title nix-repl nix repl")))
(defun kitty--send-region-to-nix-repl-tab ()
(shell-command-on-region
(if (use-region-p) (region-beginning) (point-min))
(if (use-region-p) (region-end) (point-max))
"kitty @ send-text --match-tab title:nix-repl --stdin"))
(defun org-babel-src-block-language-p (language)
(let ((block-info (org-element-at-point)))
(and (eq (car block-info) 'src-block)
(string= language (org-element-property :language block-info)))))
(defadvice +eval/send-region-to-repl (around my-send-region-to-repl activate)
(if (and (eq major-mode 'org-mode)
(org-babel-src-block-language-p "nix"))
(progn
(kitty--ensure-nix-repl-tab)
(kitty--send-region-to-nix-repl-tab))
ad-do-it))
When calling the +eval/send-region-to-repl function (SPC c s), if current major
mode is org-mode and the language of the org-babel source block is nix, it sends
the selected code to Kitty’s nix-repl tab, which runs the nix repl so that the
code is evaluated in the Nix REPL. The tab will be created if not exist.
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