[ESS] ess-toggle-underscore not working in init.el

[Stephen Eglen]

> Hi All,
>
> I'm using Vincent Goulet's fine Emacs for OSX with ess bundled.
>
> For some reason, "(ess-toggle-underscore nil)" is generating an error
> message when I include it in my .emacs.d/init.el file:
>
> Warning (initialization): An error occurred while loading
> `/Users/warnes/.emacs.d/init.el':
>
> Symbol's function definition is void: ess-toggle-underscore
>
>
> I recall this working in the past, and executing "(ess-toggle-underscore
> nil)" after emacs starts up successfully works properly.
>
> I suppose that emacs introduced 'lazy-loading' of the ess code, so that
> ess-toggle-underscore simply isn't defined until after startup is
> complete.

Yes, I think this is because of the way ESS is loaded in Vincent's fine
package.  Does something like the following (untested) work?

(eval-after-load  "ess-mode" '(ess-toggle-underscore))