Re: ebnf2ps for babel

[Eric Schulte <schulte.eric@gmail.com>]

Hi Michael,

Thanks for sharing this.

Michael Gauland <mikelygee@amuri.net> writes:

> 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.
>

I think you could probably remove the following lines.

(require 'ob-ref)
(require 'ob-comint)
(require 'ob-eval)

Aside from that nothing looks amiss.

>
> Would anyone else find this useful?
>

Personally, I hope I don't have to write a grammar any time soon, but
you never know what's around the corner...

If you could re-send ob-ebnf2ps as a patch (as generated with git
format-patch), and also add ebnf2ps to the `org-babel-load-languages'
variable in org.el I'd be very happy to apply this to the repository.

Thanks,

>
> 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
>

-- 
Eric Schulte
https://cs.unm.edu/~eschulte
PGP: 0x614CA05D