How to stop emacs from replacing underbar with <- in ess-mode

Question

ess-mode is \"Emacs speaks statistics.\" This mode is useful for editing programs for R or Splus (two separate statistics packages).

In my buffer, when

Answer 1

A more recent version which seemed to work for me, and is a lot less verbose (you essentially keep normal underscores, but can set your own key for this smart behaviour!):

(global-set-key (kbd "C-;")  (lambda () (interactive) (insert " <- ")))
(ess-toggle-underscore nil)

Insert your shortkey choice instead of C-;.