From 1709deacfdbb6eb76edf5878df106d9e1cc676fa Mon Sep 17 00:00:00 2001
From: William Waites <wwaites@tardis.ed.ac.uk>
Date: Wed, 25 Sep 2013 12:18:55 +0100
Subject: [PATCH 1/2] Initial version of ABC notation handling for Babel

---
 lisp/ob-abc.el |   87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)
 create mode 100644 lisp/ob-abc.el

diff --git a/lisp/ob-abc.el b/lisp/ob-abc.el
new file mode 100644
index 0000000..5ad7409
--- /dev/null
+++ b/lisp/ob-abc.el
@@ -0,0 +1,87 @@
+;;; ob-abc.el --- org-babel functions for template evaluation
+
+;; Copyright (C) Free Software Foundation
+
+;; Author: William Waites
+;; Keywords: literate programming, music
+;; Homepage: http://www.tardis.ed.ac.uk/wwaites
+;; 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:
+
+;;; This file adds support to Org Babel for music in ABC notation.
+;;; It requires that the abcm2ps program is installed.
+;;; See http://moinejf.free.fr/
+
+(require 'ob)
+
+;; optionally define a file extension for this language
+(add-to-list 'org-babel-tangle-lang-exts '("abc" . "abc"))
+
+;; optionally declare default header arguments for this language
+(defvar org-babel-default-header-args:abc
+  '((:results . "file") (:exports . "results"))
+  "Default arguments to use when evaluating an ABC source block.")
+
+(defun org-babel-expand-body:abc (body params)
+  "Expand BODY according to PARAMS, return the expanded body."
+  (let ((vars (mapcar #'cdr (org-babel-get-header params :var))))
+    (mapc
+     (lambda (pair)
+       (let ((name (symbol-name (car pair)))
+	     (value (cdr pair)))
+	 (setq body
+	       (replace-regexp-in-string
+		(concat "\$" (regexp-quote name))
+		(if (stringp value) value (format "%S" value))
+		body))))
+     vars)
+    body))
+
+(defun org-babel-execute:abc (body params)
+  "Execute a block of ABC code with org-babel.  This function is
+   called by `org-babel-execute-src-block'"
+  (message "executing Abc source code block")
+  (let* ((result-params (split-string (or (cdr (assoc :results params)))))
+	 (cmdline (cdr (assoc :cmdline params)))
+	 (out-file ((lambda (el)
+		      (or el
+			  (error "abc code block requires :file header argument")))
+		    ;;; For SVG or EPS output, abcm2ps will add a number for a particular page
+		    ;;; automatically. This needs to be specified in the :file argument and stripped
+		    ;;; stripped out here. There is likely a better way to do this.
+		    (replace-regexp-in-string "001" "" (cdr (assoc :file params)))))
+	 (in-file (org-babel-temp-file "abc-"))
+	 (cmd (concat "abcm2ps" " " cmdline
+		      " -O " (org-babel-process-file-name out-file)
+		      " " (org-babel-process-file-name in-file))))
+    (with-temp-file in-file (insert (org-babel-expand-body:abc body params)))
+    (org-babel-eval cmd "")
+    ;;; indicate that the file has been written
+    nil))
+
+;; This function should be used to assign any variables in params in
+;; the context of the session environment.
+(defun org-babel-prep-session:abc (session params)
+  "Return an error because abc does not support sessions."
+  (error "ABC does not support sessions"))
+
+(provide 'ob-abc)
+;;; ob-abc.el ends here
--
1.7.10.4