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// Simple Example Scanner Class
package java_cup.simple_calc;
import java_cup.runtime.*;
public class scanner {
/* single lookahead character */
protected static int next_char;
/* advance input by one character */
protected static void advance()
throws java.io.IOException
{ next_char = System.in.read(); }
/* initialize the scanner */
public static void init()
throws java.io.IOException
{ advance(); }
/* recognize and return the next complete token */
public static Symbol next_token()
throws java.io.IOException
{
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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