ob-sclang/README.org

#+TITLE: ob-sclang
#+STARTUP: showall
#+STARTUP: showstars

** Why do I even?
[[https://orgmode.org/][Org-mode]] makes [[http://literateprogramming.com/][literate programming]] easy via [[https://orgmode.org/worg/library-of-babel.html][Library of Babel]]. Il simply allows to mix text with executable /code blocks/ (which can also be extracted (/tangled/) into separate, executable files. The beauty of the Library of Babel implementation in org-mode lies in the fact that it supports many languages. I craved support for [[https://github.com/supercollider/supercollider][SuperCollider]] and craving became an itch when I needed to document a working pipeline alternating between executing sclang and shell scripts. I scratched an itch with this little module.

** How to install?
First of all, you will need emacs (>=25) and SuperCollider (with emacs support) installed. Modern emacsen and Spacemacs come with bundled org-mode. At this point I am the sole user of this plugin and have just written it so I am not itching yet for MELPA or inclusion in the official org-mode repositories, so installation is manual. You can either drop [[file:ob-sclang.el]] somewhere in your Emacs' path or add its containing directory to ~load-path~ in =.init= file:

#+BEGIN_SRC elisp
 (add-to-list 'load-path "/path/to/ob-sclang/")
#+END_SRC

You will also have to add it to =(org-babel-do-load-languages)=
#+BEGIN_SRC elisp
(require 'ob-sclang)
(org-babel-do-load-languages
    'org-babel-load-languages
    '((sclang . t)))
#+END_SRC

** And then?

Well, then you type a block like this one:
#+BEGIN_SRC org
  ,#+BEGIN_SRC sclang
    "boo".postln;
  ,#+END_SRC
#+END_SRC
And after you hit /C-c C-c/ you should see the string appear in your =SCLang:PostBuffer*=

*Note:*, make sure you execute =sclang-start= prior to executing any sclang code blocks

*** Use of variables

You can also include variables to be passed to you sclang code:
#+BEGIN_SRC org
  ,#+BEGIN_SRC sclang :var boo="hoo" :var pi=3.14159 :var year=2000 :var buf='foo
    boo.postln;
    pi.postln;
    year.postln;
    buf.postln;
  ,#+END_SRC
#+END_SRC

Will reformat your sclang body to:
#+BEGIN_SRC sclang
"hoo".postln;
3.141590.postln;
2000.postln;
"foo".asSymbol.postln;
#+END_SRC
Before passing it on to the sclang process.

The use of sclang's own global variables is persistent between code blocks so =~boo=

#+BEGIN_SRC org
  ,#+BEGIN_SRC sclang
    ~boo = "hoo";
  ,#+END_SRC
#+END_SRC

is accessible here:

#+BEGIN_SRC org
,#+BEGIN_SRC sclang
  ~boo.postln;
,#+END_SRC
#+END_SRC

** Known issues
At this point, this plugin has a very crude functionality. It allows unidirectional control of SuperCollider process running inside Emacs. As such, here is a list of issues:

Of course feel free to open questions, suggestions, discussions and even pull requests.

* Some tests

The code blocks beyond this point can be executed from an org buffer:

Post some string to SC's Post Buffer:
#+begin_src sclang
"boo".postln;
#+end_src

This python code does not need to be evaluated beforehand because it will be evaluated by sclang block below.
#+name: frompy
#+begin_src python :session sc :results value
[1,2,3,4]
#+end_src

#+RESULTS: frompy
| 1 | 2 | 3 | 4 |

And we will use this table as input data
#+name: tbl
| boo  | 5 | 9 |
| good | 7 | xa |

And here we execute some sclang that simply reads variables specified in code block's header. They include named python codeblock above and the table.
#+begin_src sclang :var x=10 y=11 z=1.1 table=tbl tb=frompy
  x.postln;
  x.class.postln;
  y.postln;
  y.class.postln;
  z.postln;
  z.class.postln;
  table.postln;
  table.class.postln;
  table[0].postln;
  tb.postln;
  tb.class.postln;
#+end_src

And this is the output to SC's Post Buffer.
#+begin_example
10
Integer
11
Integer
1.1
Float
[ [ boo, 5, 9 ], [ good, 7, xa ] ]
Array
[ boo, 5, 9 ]
[ 1, 2, 3, 4 ]
Array
#+end_example

* Local Variables                                                  :noexport:
# Local Variables:
# org-confirm-babel-evaluate: nil
# End: