Rough first draft of antifennel.el, a way to call `antifennel` CLI from within Emacs buffers

antifennel.el

;; antifennel.el --- Turn Lua code into Fennel code

(defgroup antifennel nil
  "Tool to convert Lua code into Fennel code."
  :group 'tools)

(defcustom antifennel-cli "antifennel"
  "Path to the antifennel executable"
  :type 'string
  :group 'antifennel)

;;;###autoload
(defun antifennel (beginning end)
  (interactive "r")
  (save-excursion
    (kill-ring-save beginning end)
    (let ((temp-file (make-temp-file "antifennel")))
      (write-region (substring-no-properties (car kill-ring)) nil temp-file 'append)
      (thread-first (list antifennel-cli temp-file)
        (string-join " ")
        shell-command-to-string
        kill-new)
      (switch-to-buffer
       (get-buffer-create "*antifennel*"))
      (insert (car kill-ring-yank-pointer)))))

(provide 'antifennel)

;;; antifennel.el ends here