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/*
* This file is part of %PACKAGENAME%.
*
* %PACKAGENAME% 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.
*
* %PACKAGENAME% 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 %PACKAGENAME%. If not, see <http://www.gnu.org/licenses/>.
*
* For more information please see <http://www.%PACKAGENAME%.org>
* or contact Peter Baumann via <baumann@rasdaman.com>.
*
* Copyright 2009 Jacobs University Bremen, Peter Baumann.
*/
// Simple Example Scanner Class
package java_cup.simple_calc;
import java_cup.runtime.Symbol;
public class scanner implements java_cup.runtime.Scanner {
final java.io.InputStream instream;
public scanner(java.io.InputStream is) throws java.io.IOException {
instream = is;
}
public scanner() throws java.io.IOException { this(System.in); }
/* single lookahead character */
protected int next_char = -2;
/* advance input by one character */
protected void advance()
throws java.io.IOException
{ next_char = instream.read(); }
/* initialize the scanner */
private void init()
throws java.io.IOException
{ advance(); }
/* recognize and return the next complete token */
public Symbol next_token()
throws java.io.IOException
{
if (next_char==-2) init(); // set stuff up first time we are called.
for (;;)
switch (next_char)
{
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
/* parse a decimal integer */
int i_val = 0;
do {
i_val = i_val * 10 + (next_char - '0');
advance();
} while (next_char >= '0' && next_char <= '9');
return new Symbol(sym.NUMBER, new Integer(i_val));
case ';': advance(); return new Symbol(sym.SEMI);
case '+': advance(); return new Symbol(sym.PLUS);
case '-': advance(); return new Symbol(sym.MINUS);
case '*': advance(); return new Symbol(sym.TIMES);
case '/': advance(); return new Symbol(sym.DIVIDE);
case '%': advance(); return new Symbol(sym.MOD);
case '(': advance(); return new Symbol(sym.LPAREN);
case ')': advance(); return new Symbol(sym.RPAREN);
case -1: return new Symbol(sym.EOF);
default:
/* in this simple scanner we just ignore everything else */
advance();
break;
}
}
};
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