Automatically reload interactive haskell-mode buffers (Doom emacs)

auto-reload-haskell.el

  (add-hook 'interactive-haskell-mode-hook 'haskell-auto-reload-minor-mode)

  (defvar haskell-auto-reload-every-n-sec 1
    "When non-nil, automatically reloads haskell buffers after Emacs has been idle for N seconds.")

  (defvar haskell-reload-timer nil
    "Variable used to store the idle timer.")

  (define-minor-mode haskell-auto-reload-minor-mode
    "Minor mode for automatically reloading interactive haskell buffers."
    :lighter "HR"

    (when haskell-reload-timer (cancel-timer haskell-reload-timer))

    (if haskell-auto-reload-minor-mode
        (progn
          ;; don't trim whitespace in the buffer
          (when (featurep 'ws-butler)
            (setq ws-butler-keep-whitespace-before-point t))
          (add-hook 'after-save-hook 'try-reload-haskell nil t)
          (add-hook 'evil-normal-state-entry-hook 'try-save-haskell nil t)
          (when haskell-auto-reload-every-n-sec
            (setq haskell-reload-timer
                  (run-with-idle-timer
                   haskell-auto-reload-every-n-sec t
                   'try-save-haskell))))
      (progn
        (remove-hook 'after-save-hook 'try-reload-haskell t))))

  (defun try-reload-haskell ()
    (when (and
           (derived-mode-p 'haskell-mode)
           (haskell-session-maybe))
      (haskell-process-reload)))

  (defun try-save-haskell ()
    (when (and
           (evil-normal-state-p)
           (buffer-modified-p)
           (derived-mode-p 'haskell-mode)
           (haskell-session-maybe))
      (save-buffer)))