feat(emacs/README.md): add elisp which installs required packages

src/emacs/README.md

@@ -11,10 +11,11 @@ Requirement
 ``lean-mode`` requires [Emacs 24][emacs24] and following (optional)
 packages which can be installed via <kbd>M-x package-install</kbd>.
 
+ - [company][company]
  - [dash][dash]
  - [dash-functional][dash]
- - [flycheck][flycheck]
  - [fill-column-indicator][fci]
+ - [flycheck][flycheck]
  - [whitespace-cleanup-mode][wcm]
 
 To install them, you need to have [MELPA][MELPA] in your
@@ -32,13 +33,26 @@ code:
 [wcm]: https://github.com/purcell/whitespace-cleanup-mode
 [MELPA]: http://melpa.milkbox.net
 [dash]: https://github.com/magnars/dash.el
-
+[company]: http://company-mode.github.io/
-Setup
 -----
 
 Put the following elisp code on your emacs setup:
 
 ```elisp
+(require 'package)
+(add-to-list 'package-archives
+             '("melpa" . "http://melpa.milkbox.net/packages/") t)
+(package-initialize)
+(when (not package-archive-contents) (package-refresh-contents))
+
+;; Install required packages for lean-mode
+(defvar lean-mode-required-packages
+  '(company dash dash-functional flycheck whitespace-cleanup-mode fill-column-indicator))
+(dolist (p lean-mode-required-packages)
+  (when (not (package-installed-p p))
+    (package-install p)))
+
+;; Set up lean-root path
 (setq lean-rootdir "~/projects/lean")
 (setq-local lean-emacs-path
             (concat (file-name-as-directory lean-rootdir)
@@ -47,11 +61,10 @@ Put the following elisp code on your emacs setup:
 (add-to-list 'load-path (expand-file-name lean-emacs-path))
 (require 'lean-mode)
 
-;; lean customization
+;; Customization for lean-mode
-(customize-set-variable 'lean-show-rule-column-method 'vline)
-(customize-set-variable 'lean-rule-column 100)
-(customize-set-variable 'lean-rule-color "#ff0000")
 (customize-set-variable 'lean-delete-trailing-whitespace t)
+(customize-set-variable 'lean-flycheck-use t)
+(customize-set-variable 'lean-eldoc-use t)
 ```
 
 Key Bindings

src/emacs/lean-company.el

@@ -0,0 +1,81 @@
+(require 'company)
+(defun company-lean ()
+  (set (make-local-variable 'company-backends) '(company-lean))
+  (company-mode))
+(add-hook 'lean-mode-hook 'company-lean)
+
+(setq company-tooltip-limit 20)                      ; bigger popup window
+(setq company-idle-delay .3)                         ; decrease delay before autocompletion popup shows
+(setq company-echo-delay 0)                          ; remove annoying blinking
+(setq company-begin-commands '(self-insert-command)) ; start autocompletion only after typing
+
+(defun company-lean--prefix ()
+  "Returns the symbol to complete. Also, if point is on a dot,
+triggers a completion immediately."
+  (if company-lean-begin-after-member-access
+      (company-grab-symbol-cons "\\." 1)
+    (company-grab-symbol)))
+
+(defun company-go--invoke-autocomplete ()
+  (let ((temp-buffer (generate-new-buffer "*leancompany*")))
+    (prog2
+	(call-process-region (point-min)
+			     (point-max)
+			     "leancompany"
+			     nil
+			     temp-buffer
+			     nil
+			     "-f=csv"
+			     "autocomplete"
+			     (or (buffer-file-name) "")
+			     (concat "c" (int-to-string (- (point) 1))))
+	(with-current-buffer temp-buffer (buffer-string))
+      (kill-buffer temp-buffer))))
+
+(defun company-lean--candidates ()
+  (company-lean--get-candidates (split-string (company-lean--invoke-autocomplete) "\n" t)))
+
+;;;###autoload
+(defun company-lean (command &optional arg &rest ignored)
+  (case command
+    (prefix (and (derived-mode-p 'lean-mode)
+                 (not (company-in-string-or-comment))
+                 (or (company-lean--prefix) 'stop)))
+    (candidates (company-lean--candidates))
+    (meta (get-text-property 0 'meta arg))
+    (annotation
+     (when company-lean-show-annotation
+       (get-text-property 0 'meta arg)))
+    (location (company-lean--location arg))
+    (sorted t)))
+
+(provide 'company-lean)
+
+(defun company-lean--doc-buffer (candidate)
+    (message "doc candidate = %S" candidate)
+  (company-doc-buffer (get-text-property 0 'doc candidate)))
+
+(defun company-lean--annotation (candidate)
+  (message "annotation candidate = %S" candidate)
+    (let ((anno (get-text-property 0 'kind candidate)))
+      (when anno (concat " blabla" anno)))
+    " : annotation1")
+
+(defun company-lean--candidates (prefix)
+  (cl-loop for x in '("foobar" "foobaz" "foobarbaz")
+           collect x
+           ))
+
+(defun company-my-backend (command &optional arg &rest ignored)
+  (interactive (list 'interactive))
+  (case command
+    (interactive (company-begin-backend 'company-my-backend))
+    (prefix (when (looking-back "foo\\>")
+              (match-string 0)))
+    (candidates (company-lean--candidates arg))
+    (annotation (company-lean--annotation arg))
+    ))
+
+(set (make-local-variable 'company-backends) '(company-my-backend))
+(company-mode)
+