From 32103b2ddc5476934272b8fa9821f200fcf32dcb Mon Sep 17 00:00:00 2001
From: Jack Kamm <jackkamm@gmail.com>
Date: Tue, 2 May 2017 15:18:23 +0100
Subject: [PATCH] added ess layer variable ess-disable-underscore-assign

---
 layers/+lang/ess/README.org  | 23 ++++++++++++-----------
 layers/+lang/ess/config.el   |  3 +++
 layers/+lang/ess/packages.el |  2 ++
 3 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/layers/+lang/ess/README.org b/layers/+lang/ess/README.org
index 91555210c..e4d9add1e 100644
--- a/layers/+lang/ess/README.org
+++ b/layers/+lang/ess/README.org
@@ -51,19 +51,20 @@ Helpers for inspecting objects at point are available in R buffers only.
 | ~SPC m h t~ | view table using [ess-R-data-view][ess-R-data-view]                 |
 
 * Options
-=ess-smart-equals= is disabled by default. In order to enable it, set in your
-=~/.spacemacs=
+
+To turn off the automatic replacement of underscores by =<-=,
+set in your =~/.spacemacs=:
+
+#+BEGIN_SRC emacs-lisp
+  (setq-default dotspacemacs-configuration-layers '((ess :variables
+                                                         ess-disable-underscore-assign t)))
+#+END_SRC
+
+Alternatively you may enable =ess-smart-equals=, which also disables
+replacement of underscores by =<-=, and additionally replace the equals sign with
+=<-= when appropriate:
 
 #+BEGIN_SRC emacs-lisp
   (setq-default dotspacemacs-configuration-layers '((ess :variables
                                                          ess-enable-smart-equals t)))
 #+END_SRC
-
-To turn off the automatic replacement of underscores by =<-=, add the following
-hook:
-
-#+begin_src emacs-lisp
-  (add-hook 'ess-mode-hook
-            (lambda ()
-              (ess-toggle-underscore nil)))
-#+end_src
diff --git a/layers/+lang/ess/config.el b/layers/+lang/ess/config.el
index 5d33842c7..04902ec93 100644
--- a/layers/+lang/ess/config.el
+++ b/layers/+lang/ess/config.el
@@ -13,3 +13,6 @@
 
 (defvar ess-enable-smart-equals nil
   "If non-nil smart-equal support is enabled")
+
+(defvar ess-disable-underscore-assign nil
+  "If non-nil, disables underscore _ being a shortcut for assignment <-")
diff --git a/layers/+lang/ess/packages.el b/layers/+lang/ess/packages.el
index bea486cc4..9486ced9a 100644
--- a/layers/+lang/ess/packages.el
+++ b/layers/+lang/ess/packages.el
@@ -71,6 +71,8 @@
           ess-expression-offset 2
           ess-nuke-trailing-whitespace-p t
           ess-default-style 'DEFAULT)
+    (if ess-disable-underscore-assign
+      (ess-toggle-underscore nil))
 
     (spacemacs/set-leader-keys-for-major-mode 'ess-julia-mode
       "'"  'julia