| /* |
| * Copyright (c) 1999, 2013, Oracle and/or its affiliates. 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.tools.javac.parser; |
| |
| import java.nio.*; |
| import java.util.List; |
| import java.util.ArrayList; |
| |
| import com.sun.tools.javac.util.Position.LineMap; |
| import com.sun.tools.javac.parser.JavaTokenizer.*; |
| |
| import static com.sun.tools.javac.parser.Tokens.*; |
| |
| /** 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 supported API. |
| * 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 class Scanner implements Lexer { |
| |
| private Tokens tokens; |
| |
| /** The token, set by nextToken(). |
| */ |
| private Token token; |
| |
| /** The previous token, set by nextToken(). |
| */ |
| private Token prevToken; |
| |
| /** Buffer of saved tokens (used during lookahead) |
| */ |
| private List<Token> savedTokens = new ArrayList<Token>(); |
| |
| private JavaTokenizer tokenizer; |
| |
| /** |
| * Create a scanner from the input array. This method might |
| * modify the array. To avoid copying the input array, ensure |
| * that {@code inputLength < input.length} or |
| * {@code input[input.length -1]} is a white space character. |
| * |
| * @param fac the factory which created this Scanner |
| * @param buf the input, might be modified |
| * Must be positive and less than or equal to input.length. |
| */ |
| protected Scanner(ScannerFactory fac, CharBuffer buf) { |
| this(fac, new JavaTokenizer(fac, buf)); |
| } |
| |
| protected Scanner(ScannerFactory fac, char[] buf, int inputLength) { |
| this(fac, new JavaTokenizer(fac, buf, inputLength)); |
| } |
| |
| protected Scanner(ScannerFactory fac, JavaTokenizer tokenizer) { |
| this.tokenizer = tokenizer; |
| tokens = fac.tokens; |
| token = prevToken = DUMMY; |
| } |
| |
| public Token token() { |
| return token(0); |
| } |
| |
| public Token token(int lookahead) { |
| if (lookahead == 0) { |
| return token; |
| } else { |
| ensureLookahead(lookahead); |
| return savedTokens.get(lookahead - 1); |
| } |
| } |
| //where |
| private void ensureLookahead(int lookahead) { |
| for (int i = savedTokens.size() ; i < lookahead ; i ++) { |
| savedTokens.add(tokenizer.readToken()); |
| } |
| } |
| |
| public Token prevToken() { |
| return prevToken; |
| } |
| |
| public void nextToken() { |
| prevToken = token; |
| if (!savedTokens.isEmpty()) { |
| token = savedTokens.remove(0); |
| } else { |
| token = tokenizer.readToken(); |
| } |
| } |
| |
| public Token split() { |
| Token[] splitTokens = token.split(tokens); |
| prevToken = splitTokens[0]; |
| token = splitTokens[1]; |
| return token; |
| } |
| |
| public LineMap getLineMap() { |
| return tokenizer.getLineMap(); |
| } |
| |
| public int errPos() { |
| return tokenizer.errPos(); |
| } |
| |
| public void errPos(int pos) { |
| tokenizer.errPos(pos); |
| } |
| } |