ob-sclang.el: add ob-sclang for sclang Org-mode babel support

* ob-sclang.el (org-babel-execute:sclang): support evaluating sclang
  code in Org-mode Babel.

Support sclang evaluation in Org-mode Babel.

contrib/lisp/ob-sclang.el

@@ -0,0 +1,102 @@
+;;; ob-sclang.el --- SCLang support for Org-mode Babel -*- lexical-binding: t; -*-
+;;; -*- coding: utf-8 -*-
+
+;; Copyright (C) 2011-2017 Free Software Foundation, Inc.
+
+;; Authors: stardiviner <numbchild@gmail.com>
+;; Package-Version: 0.1
+;; Keywords: babel sclang
+
+;; This file is not part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; `ob-sclang' requires `sclang-interp' from SuperCollider.
+;; Usually SuperCollider dependencies for Emacs are at /usr/share/emacs/site-lisp/SuperCollider/
+;; You can install SuperCollider following this article:
+;; https://github.com/supercollider/supercollider#building-the-source-code
+
+;; Usage:
+
+;; Support to evaluate sclang Org-mode src block with function `sclang-eval-string'.
+
+;; For example:
+
+;; #+BEGIN_SRC sclang :results none
+;; "Hello World".postln;
+;; #+END_SRC
+;;
+;; *NOTE* Temporary output to org-babel result output is not supported.
+;; Because `sclang-eval-string' will send output to Sclang Post Buffer.
+;; And command line `sclang' execute will not automatically stop after finished execution.
+;;
+;; #+BEGIN_SRC sclang :results none
+;; // modulate a sine frequency and a noise amplitude with another sine
+;; // whose frequency depends on the horizontal mouse pointer position
+;; {
+;; var x = SinOsc.ar(MouseX.kr(1, 100));
+;; SinOsc.ar(300 * x + 800, 0, 0.1)
+;; +
+;; PinkNoise.ar(0.1 * x + 0.1)
+;; }.play;
+;; #+END_SRC
+
+
+;;; Code:
+;;; ----------------------------------------------------------------------------
+(require 'org)
+(require 'ob)
+
+(require 'sclang-interp)
+
+(defgroup ob-sclang nil
+  "org-mode blocks for SuperCollider SCLang."
+  :group 'org)
+
+;;;###autoload
+(defun org-babel-execute:sclang (body params)
+  "Org-mode Babel sclang hook for evaluate `BODY' with `PARAMS'."
+  (unless (or (equal (buffer-name) sclang-post-buffer)
+              (sclang-get-process))
+    (sclang-start))
+  
+  ;; (let* ((db (or (cdr (assoc :db params))
+  ;;                ob-mongo:default-db))
+  ;;        (cmd (mapconcat 'identity (list "mongo" "--quiet" db) " ")))
+  ;;   (org-babel-eval cmd body))
+  
+  (sclang-eval-string body t)
+
+  ;; (let ((cmd "sclang -r -s -D"))
+  ;;   (org-babel-eval cmd body))
+  )
+
+(defvar org-babel-default-header-args:sclang nil)
+
+(setq org-babel-default-header-args:sclang
+      '((:session . "*SCLang:Workspace*")
+        (:output . "none")) ; TODO: temporary can't find way to let sclang output to stdout for org-babel.
+      )
+
+;;;###autoload
+(with-eval-after-load "org"
+  (add-to-list 'org-src-lang-modes '("sclang" . sclang)))
+
+;;; ----------------------------------------------------------------------------
+
+(provide 'ob-sclang)
+
+;;; ob-sclang.el ends here