Add ReasonML

languages/reason.el

@@ -0,0 +1,21 @@
+(use-package merlin
+  :defer t
+  :ensure t)
+
+(use-package reason-mode
+  :defer t
+  :ensure t
+  :config (setq refmt-command 'opam))
+
+(let ((opam-share (ignore-errors (car (process-lines "opam" "config" "var" "share")))))
+  (when (and opam-share (file-directory-p opam-share))
+    ;; Register Merlin
+    (add-to-list 'load-path (expand-file-name "emacs/site-lisp" opam-share))
+    (autoload 'merlin-mode "merlin" nil t nil)
+    ;; Use opam switch to lookup ocamlmerlin binary
+    (setq merlin-command 'opam)))
+
+(add-hook 'reason-mode-hook
+          (lambda ()
+            (add-hook 'before-save-hook #'refmt-before-save)))
+(add-hook 'reason-mode-hook 'merlin-mode)