example.lisp

   1 ;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10; -*-
   2 ;;;
   3 ;;; example.lisp --- Sample code showing use of cl-opossum.
   4
   5 ;; Copyright (C) 2008 Utz-Uwe Haus <lisp@uuhaus.de>
   6 ;; $Id$
   7 ;; This code is free software; you can redistribute it and/or modify
   8 ;; it under the terms of the version 3 of the GNU General
   9 ;; Public License as published by the Free Software Foundation, as
  10 ;; clarified by the prequel found in LICENSE.Lisp-GPL-Preface.
  11 ;;
  12 ;; This code is distributed in the hope that it will be useful, but
  13 ;; without any warranty; without even the implied warranty of
  14 ;; merchantability or fitness for a particular purpose. See the GNU
  15 ;; Lesser General Public License for more details.
  16 ;;
  17 ;; Version 3 of the GNU General Public License is in the file
  18 ;; LICENSE.GPL that was distributed with this file. If it is not
  19 ;; present, you can access it from
  20 ;; http://www.gnu.org/copyleft/gpl.txt (until superseded by a
  21 ;; newer version) or write to the Free Software Foundation, Inc., 59
  22 ;; Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23 ;;
  24 ;; Commentary:
  25
  26 ;; Load this file into your lisp to see how cl-opossum can be utilized
  27 ;; in your own programs.
  28
  29 ;;; Code:
  30
  31
  32
  33 (in-package #:CL-USER)
  34 \f
  35 ;; load the opossum package
  36 (asdf:operate 'asdf:load-op :opossum)
  37
  38 ;; Create a parser for the grammar defined in example.peg, in a fresh package
  39 (setq *p* (opossum:make-string-parser "example.peg"))
  40 ;; => ...
  41
  42 ;; use the parser to parse a string
  43 (setq *t* (funcall *p* "14+7*(1+1)^2"))
  44 ;; => ...
  45
  46 ;; and try out the code generated by the grammar
  47 (eval *t*)
  48 ;; => 42