scanner.java

来自「tiger run time supporting files」· Java 代码 · 共 23 行

package java_cup.runtime;

/**
 * Defines the Scanner interface, which CUP uses in the default
 * implementation of <code>lr_parser.scan()</code>.  Integration
 * of scanners implementing <code>Scanner</code> is facilitated.
 *
 * @version last updated 23-Jul-1999
 * @author David MacMahon <[e-mail]>
 */

/*******************************************************************************
 * Interface Scanner
 * 
 * Declares the next_token() method that should be implemented by scanners. This
 * method is typically called by lr_parser.scan(). End-of-file can be indicated
 * either by returning <code>new Symbol(lr_parser.EOF_sym())</code> or <code>null</code>.
 ******************************************************************************/
public interface Scanner {
	/** Return the next token, or <code>null</code> on end-of-file. */
	public Symbol next_token() throws java.lang.Exception;
}