;;; ob-ebnf.el --- Babel Functions for EBNF -*- lexical-binding: t; -*- ;; Copyright (C) 2013-2021 Free Software Foundation, Inc. ;; Author: Michael Gauland ;; Keywords: literate programming, reproducible research ;; Homepage: https://orgmode.org ;; This file is part of GNU Emacs. ;; GNU Emacs 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 of the License, or ;; (at your option) any later version. ;; GNU Emacs 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. If not, see . ;;; Commentary: ;; Org-Babel support for using ebnf2ps to generate encapsulated postscript ;; railroad diagrams. It recognizes 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 '[' 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 customize the output. The style can also specify the ;; grammar syntax (by setting ebnf-syntax); note that only ebnf, ;; iso-ebnf, and yacc are supported by this file. ;;; Requirements: ;;; Code: (require 'ob) (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 (assq :file params))) (dest-dir (file-name-directory dest-file)) (dest-root (file-name-sans-extension (file-name-nondirectory dest-file))) (style (cdr (assq :style params))) (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