duke@1: /*
jjg@816: * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
duke@1: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@1: *
duke@1: * This code is free software; you can redistribute it and/or modify it
duke@1: * under the terms of the GNU General Public License version 2 only, as
ohair@554: * published by the Free Software Foundation. Oracle designates this
duke@1: * particular file as subject to the "Classpath" exception as provided
ohair@554: * by Oracle in the LICENSE file that accompanied this code.
duke@1: *
duke@1: * This code is distributed in the hope that it will be useful, but WITHOUT
duke@1: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@1: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@1: * version 2 for more details (a copy is included in the LICENSE file that
duke@1: * accompanied this code).
duke@1: *
duke@1: * You should have received a copy of the GNU General Public License version
duke@1: * 2 along with this work; if not, write to the Free Software Foundation,
duke@1: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@1: *
ohair@554: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@554: * or visit www.oracle.com if you need additional information or have any
ohair@554: * questions.
duke@1: */
duke@1:
duke@1: package com.sun.tools.javac.parser;
duke@1:
duke@1: import java.nio.*;
mcimadamore@1144: import java.util.List;
mcimadamore@1144: import java.util.ArrayList;
duke@1:
mcimadamore@1113: import com.sun.tools.javac.util.Position.LineMap;
mcimadamore@1113: import com.sun.tools.javac.parser.JavaTokenizer.*;
duke@1:
mcimadamore@1113: import static com.sun.tools.javac.parser.Tokens.*;
duke@1:
duke@1: /** The lexical analyzer maps an input stream consisting of
duke@1: * ASCII characters and Unicode escapes into a token sequence.
duke@1: *
jjg@581: *
This is NOT part of any supported API.
jjg@581: * If you write code that depends on this, you do so at your own risk.
duke@1: * This code and its internal interfaces are subject to change or
duke@1: * deletion without notice.
duke@1: */
duke@1: public class Scanner implements Lexer {
duke@1:
mcimadamore@1113: private Tokens tokens;
duke@1:
duke@1: /** The token, set by nextToken().
duke@1: */
duke@1: private Token token;
duke@1:
mcimadamore@1113: /** The previous token, set by nextToken().
duke@1: */
mcimadamore@1113: private Token prevToken;
duke@1:
mcimadamore@1144: /** Buffer of saved tokens (used during lookahead)
mcimadamore@1144: */
mcimadamore@1144: private List savedTokens = new ArrayList();
mcimadamore@1144:
mcimadamore@1113: private JavaTokenizer tokenizer;
duke@1: /**
duke@1: * Create a scanner from the input array. This method might
duke@1: * modify the array. To avoid copying the input array, ensure
duke@1: * that {@code inputLength < input.length} or
duke@1: * {@code input[input.length -1]} is a white space character.
duke@1: *
duke@1: * @param fac the factory which created this Scanner
duke@1: * @param input the input, might be modified
duke@1: * @param inputLength the size of the input.
duke@1: * Must be positive and less than or equal to input.length.
duke@1: */
mcimadamore@1113: protected Scanner(ScannerFactory fac, CharBuffer buf) {
mcimadamore@1113: this(fac, new JavaTokenizer(fac, buf));
duke@1: }
duke@1:
mcimadamore@1113: protected Scanner(ScannerFactory fac, char[] buf, int inputLength) {
mcimadamore@1113: this(fac, new JavaTokenizer(fac, buf, inputLength));
duke@1: }
duke@1:
mcimadamore@1113: protected Scanner(ScannerFactory fac, JavaTokenizer tokenizer) {
mcimadamore@1113: this.tokenizer = tokenizer;
mcimadamore@1113: tokens = fac.tokens;
mcimadamore@1113: token = prevToken = DUMMY;
duke@1: }
duke@1:
duke@1: public Token token() {
mcimadamore@1144: return token(0);
duke@1: }
duke@1:
mcimadamore@1144: public Token token(int lookahead) {
mcimadamore@1144: if (lookahead == 0) {
mcimadamore@1144: return token;
mcimadamore@1144: } else {
mcimadamore@1144: ensureLookahead(lookahead);
mcimadamore@1144: return savedTokens.get(lookahead - 1);
mcimadamore@1144: }
mcimadamore@1144: }
mcimadamore@1144: //where
mcimadamore@1144: private void ensureLookahead(int lookahead) {
mcimadamore@1144: for (int i = savedTokens.size() ; i < lookahead ; i ++) {
mcimadamore@1144: savedTokens.add(tokenizer.readToken());
mcimadamore@1144: }
mcimadamore@1144: }
mcimadamore@1144:
mcimadamore@1113: public Token prevToken() {
mcimadamore@1113: return prevToken;
duke@1: }
duke@1:
mcimadamore@1113: public void nextToken() {
mcimadamore@1113: prevToken = token;
mcimadamore@1144: if (!savedTokens.isEmpty()) {
mcimadamore@1144: token = savedTokens.remove(0);
mcimadamore@1144: } else {
mcimadamore@1144: token = tokenizer.readToken();
mcimadamore@1144: }
duke@1: }
duke@1:
mcimadamore@1113: public Token split() {
mcimadamore@1113: Token[] splitTokens = token.split(tokens);
mcimadamore@1113: prevToken = splitTokens[0];
mcimadamore@1113: token = splitTokens[1];
mcimadamore@1113: return token;
duke@1: }
duke@1:
mcimadamore@1113: public LineMap getLineMap() {
mcimadamore@1113: return tokenizer.getLineMap();
duke@1: }
duke@1:
duke@1: public int errPos() {
mcimadamore@1113: return tokenizer.errPos();
duke@1: }
duke@1:
duke@1: public void errPos(int pos) {
mcimadamore@1113: tokenizer.errPos(pos);
duke@1: }
duke@1: }