/*
 * [The "BSD licence"]
 * Copyright (c) 2005-2008 Terence Parr
 * All rights reserved.
 *
 * Conversion to C#:
 * Copyright (c) 2008-2009 Sam Harwell, Pixel Mine, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

tree grammar DebugTreeGrammar;

options
{
	language=CSharp3;
	tokenVocab=DebugGrammar;
	ASTLabelType=CommonTree;
}

// START:members
@header
{
//import java.util.Map;
//import java.util.HashMap;
using BigInteger = java.math.BigInteger;
using Console = System.Console;
}
// END:members

// START:rules
prog:   stat*
    ;

stat:   expr                       { string result = $expr.value.ToString();
                                     Console.Out.WriteLine($expr.value + " (about " + result[0] + "*10^" + (result.Length-1) + ")");
                                   }
    |   ^('=' ID expr)             { globalMemory[$ID.text] = $expr.value; }
    |   ^(FUNC .+)	               // ignore FUNCs - we added them to functionDefinitions already in parser.
    ;

expr returns [BigInteger value]
    :   ^('+' a=expr b=expr)       { $value = $a.value.add($b.value); }
    |   ^('-' a=expr b=expr)       { $value = $a.value.subtract($b.value); }
    |   ^('*' a=expr b=expr)       { $value = $a.value.multiply($b.value); }
    |   ^('/' a=expr b=expr)       { $value = $a.value.divide($b.value); }
    |   ^('%' a=expr b=expr)       { $value = $a.value.remainder($b.value); }
    |   ID                         { $value = getValue($ID.text); }
    |   INT                        { $value = new BigInteger($INT.text); }
    |   call                       { $value = $call.value; }
    ;

call returns [BigInteger value]
    :   ^(CALL ID expr)            { BigInteger p = $expr.value;
                                     CommonTree funcRoot = findFunction($ID.text, p);
                                     if (funcRoot == null) {
                                         Console.Error.WriteLine("No match found for " + $ID.text + "(" + p + ")");
                                     } else {
                                         // Here we set up the local evaluator to run over the
                                         // function definition with the parameter value.
                                         // This re-reads a sub-AST of our input AST!
                                         DebugTreeGrammar e = new DebugTreeGrammar(funcRoot, functionDefinitions, globalMemory, p);
                                         $value = e.expr();
                                     }
                                   }
    ;
// END:rules