Re: How to autoload Tramp methods

[Michael Albinus]

Eshel Yaron <me@eshelyaron.com> writes:

> Hi,

Hi Eshel,

> One option that comes to mind is something like:
>
> diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
> index 8961b872a8a..a82a3e564d8 100644
> --- a/lisp/net/tramp.el
> +++ b/lisp/net/tramp.el
> @@ -1794,7 +1794,12 @@ tramp-dissect-file-name
>                    :port port :localname localname :hop hop))
>         ;; The method must be known.
>         (unless (or nodefault non-essential
> -                   (assoc method tramp-methods))
> +                   (assoc method tramp-methods)
> +                      (when-let ((enable-fun
> +                                  (intern-soft
> +                                   (format "tramp-enable-%s-method" method)))
> +                                 ((functionp enable-fun)))
> +                        (funcall enable-fun)))
>           (tramp-user-error
>            v "Method `%s' is not known" method))
>         ;; Only some methods from tramp-sh.el do support multi-hops.
>
> Then in foo-tramp I could define tramp-enable-foo-method, have it return
> non-nil, give it an autoload cookie, and that's it.  How would you feel
> about such an approach?

The idea is good. However, tramp-dissect-file-name is the most often
calles function in Tramp (a workhorse), I wouldn't like to make it
heavier.

How about defining and autoloading tramp-enable-foo-method, and *also*
adding in foo-tramp.el

--8<---------------cut here---------------start------------->8---
;;;###autoload
(tramp-enable-method "foo")
--8<---------------cut here---------------end--------------->8---

In order to avoid loading foo-tramp due to this call, you must autoload
the *implementation* of tramp-enable-foo-method, like

--8<---------------cut here---------------start------------->8---
;;;###autoload
(progn (defun tramp-enable-foo-method ()
  "Enable connection to foo."
  (add-to-list 'tramp-methods
               `("foo"
                 ...))))
--8<---------------cut here---------------end--------------->8---

> Best regards,
>
> Eshel

Best regards, Michael.