165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn/* 265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * Copyright (C) 2011 The Android Open Source Project 365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * 465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * Licensed under the Apache License, Version 2.0 (the "License"); 565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * you may not use this file except in compliance with the License. 665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * You may obtain a copy of the License at 765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * 865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * http://www.apache.org/licenses/LICENSE-2.0 965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * 1065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * Unless required by applicable law or agreed to in writing, software 1165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * distributed under the License is distributed on an "AS IS" BASIS, 1265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * See the License for the specific language governing permissions and 1465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * limitations under the License. 1565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn */ 1665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 1765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 1865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Rennpackage android.filterfw.io; 1965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 2065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Rennimport java.util.regex.Matcher; 2165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Rennimport java.util.regex.Pattern; 2265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 2365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn/** 2465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn * @hide 2565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn */ 2665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Rennpublic class PatternScanner { 2765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 2865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn private String mInput; 2965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn private Pattern mIgnorePattern; 3065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn private int mOffset = 0; 3165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn private int mLineNo = 0; 3265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn private int mStartOfLine = 0; 3365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 3465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public PatternScanner(String input) { 3565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn mInput = input; 3665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 3765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 3865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public PatternScanner(String input, Pattern ignorePattern) { 3965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn mInput = input; 4065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn mIgnorePattern = ignorePattern; 4165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn skip(mIgnorePattern); 4265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 4365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 4465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public String tryEat(Pattern pattern) { 4565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn // Skip ignore pattern 4665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn if (mIgnorePattern != null) { 4765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn skip(mIgnorePattern); 4865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 4965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 5065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn // Create the matcher 5165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn Matcher matcher = pattern.matcher(mInput); 5265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn matcher.region(mOffset, mInput.length()); 5365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 5465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn // Attempt to match 5565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn String result = null; 5665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn if (matcher.lookingAt()) { 5765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn updateLineCount(mOffset, matcher.end()); 5865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn mOffset = matcher.end(); 5965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn result = mInput.substring(matcher.start(), matcher.end()); 6065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 6165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 6265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn // Skip ignore pattern 6365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn if (result != null && mIgnorePattern != null) { 6465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn skip(mIgnorePattern); 6565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 6665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 6765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn return result; 6865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 6965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 7065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public String eat(Pattern pattern, String tokenName) { 7165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn String result = tryEat(pattern); 7265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn if (result == null) { 7365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn throw new RuntimeException(unexpectedTokenMessage(tokenName)); 7465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 7565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn return result; 7665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 7765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 7865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public boolean peek(Pattern pattern) { 7965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn // Skip ignore pattern 8065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn if (mIgnorePattern != null) { 8165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn skip(mIgnorePattern); 8265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 8365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 8465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn // Create the matcher 8565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn Matcher matcher = pattern.matcher(mInput); 8665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn matcher.region(mOffset, mInput.length()); 8765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 8865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn // Attempt to match 8965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn return matcher.lookingAt(); 9065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 9165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 9265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public void skip(Pattern pattern) { 9365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn Matcher matcher = pattern.matcher(mInput); 9465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn matcher.region(mOffset, mInput.length()); 9565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn if (matcher.lookingAt()) { 9665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn updateLineCount(mOffset, matcher.end()); 9765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn mOffset = matcher.end(); 9865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 9965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 10065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 10165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public boolean atEnd() { 10265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn return mOffset >= mInput.length(); 10365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 10465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 10565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public int lineNo() { 10665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn return mLineNo; 10765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 10865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 10965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public String unexpectedTokenMessage(String tokenName) { 11065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn String line = mInput.substring(mStartOfLine, mOffset); 11165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn return "Unexpected token on line " + (mLineNo + 1) + " after '" + line + "' <- Expected " + 11265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn tokenName + "!"; 11365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 11465953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn 11565953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn public void updateLineCount(int start, int end) { 11665953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn for (int i = start; i < end; ++i) { 11765953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn if (mInput.charAt(i) == '\n') { 11865953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn ++mLineNo; 11965953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn mStartOfLine = i + 1; 12065953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 12165953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 12265953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn } 12365953da4636fbf5f0a24b8f5f2b5fa7d76ff13d9Marius Renn} 124