How to evaluate javascript buffer (by node.js) from within Emacs on Windows

Question

I am watching one of Jim Weirich's presentations about Y combinator using JavaScript in Emacs, at http://v.youku.com/v_show/id_XNDQ4NDY0NjM2.html

(The presentation is pretty much similar, I think, to what he gave at RubyConf 2012 using Ruby instead of javascript .. http://confreaks.com/videos/1287-rubyconf2012-y-not-adventures-in-functional-programming )

One thing I noticed that he was evaluating JS in the buffer from within Emacs (by node.js, as some of the error msgs shown) via "Cc v" short-cut, and also got the output back into another buffer.

I am wondering is there a simple instruction (before diving into comint/call-process details) on how to get that setup on latest Emacs on windows ...I searched, but so far no success. Btw, I alreay get node.exe installed, and can get node interactively run as a REPL in Emacs by "Mx run-js", following instruction at in an article "setting-up-emacs-as-a-javascript-editing-environment-for-fun-and-profit" (sorry not able to post more than 2 links...)

Thanks,

/bruin

Answer 1

I defined the following function and its key map. So far it works.

(defun node-js-eval-region-or-buffer ()
  "Evaluate the current buffer (or region if mark-active),
   and return the result into another buffer,
   which is to be shown in a window."
  (interactive)
  (let ((debug-on-error t) (start 1) (end 1))
    (cond
     (mark-active
      (setq start (point))
      (setq end (mark)))
     (t
      (setq start (point-min))
      (setq end (point-max))))
    (call-process-region
     start end     ; seems the order does not matter
     "node"        ; node.js
     nil           ; don't delete region
     "node.js"     ; output buffer
     nil)          ; no redisply during output
    (message "Region or buffer evaluated!")
    (setq deactivate-mark t))) ; deactive the region, regardless

(define-key global-map (kbd "C-c v") 'node-js-eval-region-or-buffer)

I still have another thing to dig a bit: how to automatically split the screen to show the output buffer? I guess it should be not too difficult...

Btw, I install Git and Node.js for Windows, and copy "node.exe" into Git's "/bin" directory (which has been added to PATH environment during installation).

Answer 2

install js3-mode

then:

(require 'js-comint)
(setq inferior-js-program-command "node --interactive")
(setenv "NODE_NO_READLINE" "1")
;; Use your favorited js mode here:
(add-hook 'js3-mode-hook '(lambda () 
                (local-set-key "\C-x\C-e" 
                       'js-send-last-sexp)
                (local-set-key "\C-\M-x" 
                       'js-send-last-sexp-and-go)
                (local-set-key "\C-cb" 
                       'js-send-buffer)
                (local-set-key "\C-c\C-b" 
                       'js-send-buffer-and-go)
                (local-set-key "\C-cl" 
                       'js-load-file-and-go)
                ))