lexer.java

是一款用JAVA 编写的编译器 具有很强的编译功能

/*
 * Copyright 2005 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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 General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package com.sun.tools.javac.parser;

import com.sun.tools.javac.util.*;
import com.sun.tools.javac.util.Position.LineMap;

/**
 * The lexical analyzer maps an input stream consisting of ASCII
 * characters and Unicode escapes into a token sequence.
 *
 * <p><b>This is NOT part of any API supported by Sun Microsystems.
 * If you write code that depends on this, you do so at your own risk.
 * This code and its internal interfaces are subject to change or
 * deletion without notice.</b>
 */
public interface Lexer {

    /**
     * Has a @deprecated been encountered in last doc comment?
     * This needs to be reset by client with resetDeprecatedFlag.
     */
    boolean deprecatedFlag();

    void resetDeprecatedFlag();

    /**
     * Returns the documentation string of the current token.
     */
    String docComment();

    /**
     * Return the last character position of the current token.
     */
    int endPos();

    /**
     * Return the position where a lexical error occurred;
     */
    int errPos();

    /**
     * Set the position where a lexical error occurred;
     */
    void errPos(int pos);

    /**
     * Build a map for translating between line numbers and
     * positions in the input.
     * 
     * @return a LineMap
     */
    LineMap getLineMap();

    /**
     * Returns a copy of the input buffer, up to its inputLength.
     * Unicode escape sequences are not translated.
     */
    char[] getRawCharacters();

    /**
     * Returns a copy of a character array subset of the input buffer.
     * The returned array begins at the <code>beginIndex</code> and
     * extends to the character at index <code>endIndex - 1</code>.
     * Thus the length of the substring is <code>endIndex-beginIndex</code>.
     * This behavior is like 
     * <code>String.substring(beginIndex, endIndex)</code>.
     * Unicode escape sequences are not translated.
     * 
     * @param beginIndex the beginning index, inclusive.
     * @param endIndex the ending index, exclusive.
     * @throws IndexOutOfBounds if either offset is outside of the
     *         array bounds
     */
    char[] getRawCharacters(int beginIndex, int endIndex);

    /**
     * Return the name of an identifier or token for the current token.
     */
    Name name();

    /**
     * Read token.
     */
    void nextToken();

    /**
     * Return the current token's position: a 0-based
     *  offset from beginning of the raw input stream
     *  (before unicode translation)
     */
    int pos();

    /**
     * Return the last character position of the previous token.
     */
    int prevEndPos();

    /**
     * Return the radix of a numeric literal token.
     */
    int radix();

    /**
     * The value of a literal token, recorded as a string.
     *  For integers, leading 0x and 'l' suffixes are suppressed.
     */
    String stringVal();

    /**
     * Return the current token, set by nextToken().
     */
    Token token();

    /**
     * Sets the current token.
     */
    void token(Token token);
}