lisp/ob-ebnf.el

   1 ;;; ob-ebnf.el --- Babel Functions for EBNF          -*- lexical-binding: t; -*-
   2
   3 ;; Copyright (C) 2013-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Michael Gauland
   6 ;; Keywords: literate programming, reproducible research
   7 ;; Homepage: http://orgmode.org
   8 ;; Version: 1.00
   9
  10 ;;; License:
  11
  12 ;; This program is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 3, or (at your option)
  15 ;; any later version.
  16 ;;
  17 ;; This program is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21 ;;
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, USA.
  26
  27 ;;; Commentary:
  28
  29 ;;; Org-Babel support for using ebnf2ps to generate encapsulated postscript
  30 ;;; railroad diagrams. It recogises these arguments:
  31 ;;;
  32 ;;;     :file is required; it must include the extension '.eps.' All the rules
  33 ;;;           in the block will be drawn in the same file. This is done by
  34 ;;;           inserting a '[<file>' comment at the start of the block (see the
  35 ;;;           documentation for ebnf-eps-buffer for more information).
  36 ;;;
  37 ;;;     :style specifies a value in ebnf-style-database. This provides the
  38 ;;;            ability to customise the output. The style can also specify the
  39 ;;;            grammar syntax (by setting ebnf-syntax); note that only ebnf,
  40 ;;;            iso-ebnf, and yacc are supported by this file.
  41
  42 ;;; Requirements:
  43
  44 ;;; Code:
  45 (require 'ob)
  46 (require 'ebnf2ps)
  47
  48 ;; optionally declare default header arguments for this language
  49 (defvar org-babel-default-header-args:ebnf '((:style . nil)))
  50
  51 ;; Use ebnf-eps-buffer to produce an encapsulated postscript file.
  52 ;;
  53 (defun org-babel-execute:ebnf (body params)
  54   "Execute a block of Ebnf code with org-babel.  This function is
  55 called by `org-babel-execute-src-block'"
  56   (save-excursion
  57     (let* ((dest-file (cdr (assq :file params)))
  58            (dest-dir (file-name-directory dest-file))
  59            (dest-root (file-name-sans-extension
  60                        (file-name-nondirectory dest-file)))
  61            (style (cdr (assq :style params)))
  62            (result nil))
  63       (with-temp-buffer
  64         (when style (ebnf-push-style style))
  65         (let ((comment-format
  66                (cond ((string= ebnf-syntax 'yacc) "/*%s*/")
  67                      ((string= ebnf-syntax 'ebnf) ";%s")
  68                      ((string= ebnf-syntax 'iso-ebnf) "(*%s*)")
  69                      (t (setq result
  70                               (format "EBNF error: format %s not supported."
  71                                       ebnf-syntax))))))
  72           (setq ebnf-eps-prefix dest-dir)
  73           (insert (format comment-format (format "[%s" dest-root)))
  74           (newline)
  75           (insert body)
  76           (newline)
  77           (insert (format comment-format (format "]%s" dest-root)))
  78           (ebnf-eps-buffer)
  79           (when style (ebnf-pop-style))))
  80       result)))
  81
  82 (provide 'ob-ebnf)
  83 ;;; ob-ebnf.el ends here