;;; org-babel-lob.el --- The Library of Babel: off-the-shelf functions for data analysis and plotting using org-babel

;; Copyright (C) 2009 Dan Davison, Eric Schulte

;; Author: Dan Davison, Eric Schulte
;; Keywords: literate programming, reproducible research
;; Homepage: http://orgmode.org
;; Version: 0.01

;;; License:

;; This program 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, or (at your option)
;; any later version.
;;
;; This program 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;; See org-babel.org in the parent directory for more information

;;; Code:
(require 'org)

(defun org-babel-execute:babel (body params)
  "Execute a library-of-babel block.

  These blocks do not have their own body. Instead they use a :srcname
  header argument to reference a different source block, whose body
  they use. Source blocks in the library of babel should use a
  standard naming scheme for the variable containing the input data
  for analysis / plotting. E.g. if that variable is always called
  __data__ then one of these bodyless babel blocks will call a library
  of babel block using :var __data__=<some reference>

  This function is called by `org-babel-execute-src-block'."
  (message "executing babel source code block...")
  (save-window-excursion
    (let ((srcname (cdr (assoc :srcname params))))
      
      ;; now locate the source block specified by srcname (it might be
      ;; in the library of babel), and construct a new source block
      ;; as follows:
      ;;
      ;; 1. The lang is the lang of the referenced source block
      ;; 2. The header args are those from the current #+begin_src babel block
      ;; 3. The body is from the reference source block

      ;; If using a library of babel function, then the
      ;; resposnsibility id on the caller to name the :var arg(s)
      ;; correctly. We could adopt a standard name such as __data__
      ;; for the input data for plotting / analysis. Thus in lob
      ;; source blocks the data variable would be referred to as
      ;; __data__ in the code, and the babel block would use :var
      ;; __data__=<some reference>

      ;; Now execute the constructed source block, ensuring that this
      ;; buffer receives the appropriate output, and only receives a
      ;; copy of the referenced source block if requested
)))

(provide 'org-babel-lob)