I've had a play with adding babel support for ebnf2ps, to generate
railroad diagrams for a grammar.
I'd appreciate any comments on the attached code.
Would anyone else find this useful?
Kind Regards,
Mike Gauland
;;; ob-ebnf.el --- org-babel functions for ebnf evaluation
;; Copyright (C) your name here
;; Author: Michael Gauland
;; 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:
;;; Org-Babel support for using ebnf2ps to generate encapsulated postscript
;;; railroad diagrams. It recogises these arguments:
;;;
;;; :file is required; it must include the extension '.eps.' All the rules
;;; in the block will be drawn in the same file. This is done by
;;; inserting a '[<file>' comment at the start of the block (see the
;;; documentation for ebnf-eps-buffer for more information).
;;;
;;; :style specifies a value in ebnf-style-database. This provides the
;;; ability to customise the output. The style can also specify the
;;; gramnmar syntax (by setting ebnf-syntax); note that only ebnf,
;;; iso-ebnf, and yacc are supported by this file.
;;; Requirements:
;;; Code:
(require 'ob)
(require 'ob-ref)
(require 'ob-comint)
(require 'ob-eval)
(require 'ebnf2ps)
;; optionally declare default header arguments for this language
(defvar org-babel-default-header-args:ebnf '((:style . nil)))
;; Use ebnf-eps-buffer to produce an encapsulated postscript file.
;;
(defun org-babel-execute:ebnf (body params)
"Execute a block of Ebnf code with org-babel. This function is
called by `org-babel-execute-src-block'"
(save-excursion
(let* ((dest-file (cdr (assoc :file params)))
(dest-dir (file-name-directory dest-file))
(dest-root (file-name-sans-extension
(file-name-nondirectory dest-file)))
(dest-ext (file-name-extension dest-file))
(style (cdr (assoc :style params)))
(current-dir default-directory)
(result nil))
(with-temp-buffer
(when style (ebnf-push-style style))
(let
((comment-format
(cond ((string= ebnf-syntax 'yacc) "/*%s*/")
((string= ebnf-syntax 'ebnf) ";%s")
((string= ebnf-syntax 'iso-ebnf) "(*%s*)")
(t (setq result
(format "EBNF error: format %s not supported."
ebnf-syntax))))))
(setq ebnf-eps-prefix dest-dir)
(insert (format comment-format (format "[%s" dest-root)))
(newline)
(insert body)
(newline)
(insert (format comment-format (format "]%s" dest-root)))
(ebnf-eps-buffer)
(when style (ebnf-pop-style))))
result
)))
(provide 'ob-ebnf)
;;; ob-ebnf.el ends here
#+TITLE: Org Babel EBNF Sample
#+AUTHOR: Michael Gauland
#+EMAIL: mikely...@amuri.net
#+DATE: {{{time(%Y-%m-%d %H:%M)}}}
#+LaTeX_CLASS: article
#+LaTeX_CLASS_OPTIONS: [a4paper]
#+LaTeX_HEADER: \usepackage{epstopdf}
#+LATEX_HEADER: \definecolor{mygray}{gray}{0.8}
#+LATEX_HEADER: \lstset{rulesepcolor=\color{mygray}}
#+LaTeX_HEADER:
\lstdefinelanguage{ebnf}{rulesepcolor=\color{cyan},frameround=tttt,backgroundcolor=\color{mygray}}
#+PROPERTY: exports both
* EBNF
#+HEADER: :file (org-babel-temp-file "./temp" ".eps")
#+BEGIN_SRC ebnf
sequence = "this" "that".
alternation = "this" | "that".
#+END_SRC
#+RESULTS:
[[file:/tmp/babel-5910UgK/temp5910f9T.eps]]
* ISO-EBNF
#+HEADER: :file (org-babel-temp-file "./temp" ".eps")
#+HEADER: :style 'iso-ebnf
#+BEGIN_SRC ebnf
sequence = "this", "that";
alternation = "this" | "that";
#+END_SRC
#+RESULTS:
[[file:/tmp/babel-5910UgK/temp5910S6B.eps]]
* YACC
#+HEADER: :file (org-babel-temp-file "./temp" ".eps")
#+HEADER: :style 'yacc
#+BEGIN_SRC ebnf
%%
sequence: 'this' 'that';
alternation: 'this' | 'that';
#+END_SRC
#+RESULTS:
[[file:/tmp/babel-5910UgK/temp5910Uun.eps]]
