(defun fennel-open-error-at-point ()
  (interactive)
  (pcase-let ((`(,file ,line)
               (string-split
                (substring-no-properties
                 (symbol-name
                  (symbol-at-point)))
                ":")))
    (find-file-other-window file)
    (goto-line (string-to-number line))))

(define-key fennel-repl-mode-map (kbd "C-c .") 'fennel-open-error-at-point)

Generated by alexjgriffith using scpaste at Fri Apr 21 18:46:10 2023. EDT. (original)