1 package java_cup.runtime;
4 * Defines the Scanner interface, which CUP uses in the default
5 * implementation of <code>lr_parser.scan()</code>. Integration
6 * of scanners implementing <code>Scanner</code> is facilitated.
8 * @version last updated 23-Jul-1999
9 * @author David MacMahon <davidm@smartsc.com>
12 /* *************************************************
15 Declares the next_token() method that should be
16 implemented by scanners. This method is typically
17 called by lr_parser.scan(). End-of-file can be
18 indicated either by returning
19 <code>new Symbol(lr_parser.EOF_sym())</code> or
21 ***************************************************/
22 public interface Scanner {
23 /** Return the next token, or <code>null</code> on end-of-file. */
24 public Symbol next_token() throws java.lang.Exception;