\
\  INFIX CALCULATOR GRAMMAR DEFINITIONS
\
\  Copyright (C) 1990 by Mikael R.K. Patel
\
\  Computer Aided Design Laboratory (CADLAB)
\  Department of Computer and Information Science
\  Linkoping University
\  S-581 83 LINKOPING
\  SWEDEN
\
\  Email: mip@ida.liu.se
\
\  Started on: 21 February 1990
\
\  Last updated on: 22 February 1990
\
\  Dependencies:
\       (forth) forth, parser, bnf
\
\  Description:
\       Infix notation grammar definitions and semantic binding.
\       Translates infix notation to postfix (forth).
\	Grammar defined using Extended Backus-Naur Form package.
\
\  Copying:
\       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 1, 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 this program; see the file COPYING.  If not, write to
\       the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 

.( Loading Backus-Naur Form Infix Calculator definitions...) cr

#include parser.f83
#include bnf.f83

parser forth definitions

\ Exported calculator grammar symbol

vocabulary calculator

symbol calc

parser calculator definitions

\ Internal semantic actions

: .number ( x -- )
  . 					( Semantic action to show binding)
;

\ Internal grammar symbols

symbol expr
symbol $
symbol term
symbol expr0
symbol expr1
symbol -
symbol +
symbol fact
symbol term0
symbol *
symbol /
symbol mod
symbol (
symbol )

\ Factorized and left-to-right execution grammar for expressions

bnf interact

<calc> ::= <expr> <eoln> @ calculator: .number	
<expr> ::= <term> <expr0>
<expr0> ::= <expr1> <expr0>
         |  <empty> 
<expr1> ::= - <term> @ forth: -
	  |  + <term> @ forth: + 
<term> ::= <fact> <term0> 
<term0> ::= * <term> @ forth: * 
	 |  / <term> @ forth: / 
         |  mod <term> @ forth: mod 
	 |  <empty> 
<fact> ::= ( <expr> ) 
        |  - <fact> @ forth: negate 
	|  <number> 

forth

forth only