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/*
* This file is part of Petascope.
*
* Petascope is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* Petascope 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Petascope. If not, see <http://www.gnu.org/licenses/>.
*
* For more information please see <http://www.Petascope.org>
* or contact Peter Baumann via <baumann@rasdaman.com>.
*
* Copyright 2009 Jacobs University Bremen, Peter Baumann.
*/
package java_cup.runtime;
/**
* Defines the Symbol class, which is used to represent all terminals
* and nonterminals while parsing. The lexer should pass CUP Symbols
* and CUP returns a Symbol.
*/
/* ****************************************************************
Class Symbol
what the parser expects to receive from the lexer.
the token is identified as follows:
sym: the symbol type
parse_state: the parse state.
value: is the lexical value of type Object
left : is the left position in the original input file
right: is the right position in the original input file
******************************************************************/
public class Symbol {
/*******************************
Constructor for l,r values
*******************************/
public Symbol(int id, int l, int r, Object o) {
this(id);
left = l;
right = r;
value = o;
}
/*******************************
Constructor for no l,r values
********************************/
public Symbol(int id, Object o) {
this(id, -1, -1, o);
}
/*****************************
Constructor for no value
***************************/
public Symbol(int id, int l, int r) {
this(id, l, r, null);
}
/***********************************
Constructor for no value or l,r
***********************************/
public Symbol(int sym_num) {
this(sym_num, -1);
left = -1;
right = -1;
value = null;
}
/***********************************
Constructor to give a start state
***********************************/
Symbol(int sym_num, int state)
{
sym = sym_num;
parse_state = state;
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** The symbol number of the terminal or non terminal being represented */
public int sym;
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** The parse state to be recorded on the parse stack with this symbol.
* This field is for the convenience of the parser and shouldn't be
* modified except by the parser.
*/
public int parse_state;
/** This allows us to catch some errors caused by scanners recycling
* symbols. For the use of the parser only. [CSA, 23-Jul-1999] */
boolean used_by_parser = false;
/*******************************
The data passed to parser
*******************************/
public int left, right;
public Object value;
/*****************************
Printing this token out. (Override for pretty-print).
****************************/
public String toString() { return "#"+sym; }
}
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