--- /dev/null
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.lucene.analysis.wikipedia;
+
+import org.apache.lucene.analysis.Tokenizer;
+import org.apache.lucene.analysis.tokenattributes.CharTermAttribute;
+import org.apache.lucene.analysis.tokenattributes.FlagsAttribute;
+import org.apache.lucene.analysis.tokenattributes.OffsetAttribute;
+import org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute;
+import org.apache.lucene.analysis.tokenattributes.TypeAttribute;
+import org.apache.lucene.util.AttributeSource;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.util.*;
+
+
+/**
+ * Extension of StandardTokenizer that is aware of Wikipedia syntax. It is based off of the
+ * Wikipedia tutorial available at http://en.wikipedia.org/wiki/Wikipedia:Tutorial, but it may not be complete.
+ * <p/>
+ * <p/>
+ * @lucene.experimental
+ */
+public final class WikipediaTokenizer extends Tokenizer {
+ public static final String INTERNAL_LINK = "il";
+ public static final String EXTERNAL_LINK = "el";
+ //The URL part of the link, i.e. the first token
+ public static final String EXTERNAL_LINK_URL = "elu";
+ public static final String CITATION = "ci";
+ public static final String CATEGORY = "c";
+ public static final String BOLD = "b";
+ public static final String ITALICS = "i";
+ public static final String BOLD_ITALICS = "bi";
+ public static final String HEADING = "h";
+ public static final String SUB_HEADING = "sh";
+
+ public static final int ALPHANUM_ID = 0;
+ public static final int APOSTROPHE_ID = 1;
+ public static final int ACRONYM_ID = 2;
+ public static final int COMPANY_ID = 3;
+ public static final int EMAIL_ID = 4;
+ public static final int HOST_ID = 5;
+ public static final int NUM_ID = 6;
+ public static final int CJ_ID = 7;
+ public static final int INTERNAL_LINK_ID = 8;
+ public static final int EXTERNAL_LINK_ID = 9;
+ public static final int CITATION_ID = 10;
+ public static final int CATEGORY_ID = 11;
+ public static final int BOLD_ID = 12;
+ public static final int ITALICS_ID = 13;
+ public static final int BOLD_ITALICS_ID = 14;
+ public static final int HEADING_ID = 15;
+ public static final int SUB_HEADING_ID = 16;
+ public static final int EXTERNAL_LINK_URL_ID = 17;
+
+ /** String token types that correspond to token type int constants */
+ public static final String [] TOKEN_TYPES = new String [] {
+ "<ALPHANUM>",
+ "<APOSTROPHE>",
+ "<ACRONYM>",
+ "<COMPANY>",
+ "<EMAIL>",
+ "<HOST>",
+ "<NUM>",
+ "<CJ>",
+ INTERNAL_LINK,
+ EXTERNAL_LINK,
+ CITATION,
+ CATEGORY,
+ BOLD,
+ ITALICS,
+ BOLD_ITALICS,
+ HEADING,
+ SUB_HEADING,
+ EXTERNAL_LINK_URL
+ };
+
+ /**
+ * Only output tokens
+ */
+ public static final int TOKENS_ONLY = 0;
+ /**
+ * Only output untokenized tokens, which are tokens that would normally be split into several tokens
+ */
+ public static final int UNTOKENIZED_ONLY = 1;
+ /**
+ * Output the both the untokenized token and the splits
+ */
+ public static final int BOTH = 2;
+ /**
+ * This flag is used to indicate that the produced "Token" would, if {@link #TOKENS_ONLY} was used, produce multiple tokens.
+ */
+ public static final int UNTOKENIZED_TOKEN_FLAG = 1;
+ /**
+ * A private instance of the JFlex-constructed scanner
+ */
+ private final WikipediaTokenizerImpl scanner;
+
+ private int tokenOutput = TOKENS_ONLY;
+ private Set<String> untokenizedTypes = Collections.emptySet();
+ private Iterator<AttributeSource.State> tokens = null;
+
+ private final OffsetAttribute offsetAtt = addAttribute(OffsetAttribute.class);
+ private final TypeAttribute typeAtt = addAttribute(TypeAttribute.class);
+ private final PositionIncrementAttribute posIncrAtt = addAttribute(PositionIncrementAttribute.class);
+ private final CharTermAttribute termAtt = addAttribute(CharTermAttribute.class);
+ private final FlagsAttribute flagsAtt = addAttribute(FlagsAttribute.class);
+
+ /**
+ * Creates a new instance of the {@link WikipediaTokenizer}. Attaches the
+ * <code>input</code> to a newly created JFlex scanner.
+ *
+ * @param input The Input Reader
+ */
+ public WikipediaTokenizer(Reader input) {
+ this(input, TOKENS_ONLY, Collections.<String>emptySet());
+ }
+
+ /**
+ * Creates a new instance of the {@link org.apache.lucene.analysis.wikipedia.WikipediaTokenizer}. Attaches the
+ * <code>input</code> to a the newly created JFlex scanner.
+ *
+ * @param input The input
+ * @param tokenOutput One of {@link #TOKENS_ONLY}, {@link #UNTOKENIZED_ONLY}, {@link #BOTH}
+ * @param untokenizedTypes
+ */
+ public WikipediaTokenizer(Reader input, int tokenOutput, Set<String> untokenizedTypes) {
+ super(input);
+ this.scanner = new WikipediaTokenizerImpl(input);
+ init(tokenOutput, untokenizedTypes);
+ }
+
+ /**
+ * Creates a new instance of the {@link org.apache.lucene.analysis.wikipedia.WikipediaTokenizer}. Attaches the
+ * <code>input</code> to a the newly created JFlex scanner. Uses the given {@link org.apache.lucene.util.AttributeSource.AttributeFactory}.
+ *
+ * @param input The input
+ * @param tokenOutput One of {@link #TOKENS_ONLY}, {@link #UNTOKENIZED_ONLY}, {@link #BOTH}
+ * @param untokenizedTypes
+ */
+ public WikipediaTokenizer(AttributeFactory factory, Reader input, int tokenOutput, Set<String> untokenizedTypes) {
+ super(factory, input);
+ this.scanner = new WikipediaTokenizerImpl(input);
+ init(tokenOutput, untokenizedTypes);
+ }
+
+ /**
+ * Creates a new instance of the {@link org.apache.lucene.analysis.wikipedia.WikipediaTokenizer}. Attaches the
+ * <code>input</code> to a the newly created JFlex scanner. Uses the given {@link AttributeSource}.
+ *
+ * @param input The input
+ * @param tokenOutput One of {@link #TOKENS_ONLY}, {@link #UNTOKENIZED_ONLY}, {@link #BOTH}
+ * @param untokenizedTypes
+ */
+ public WikipediaTokenizer(AttributeSource source, Reader input, int tokenOutput, Set<String> untokenizedTypes) {
+ super(source, input);
+ this.scanner = new WikipediaTokenizerImpl(input);
+ init(tokenOutput, untokenizedTypes);
+ }
+
+ private void init(int tokenOutput, Set<String> untokenizedTypes) {
+ this.tokenOutput = tokenOutput;
+ this.untokenizedTypes = untokenizedTypes;
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see org.apache.lucene.analysis.TokenStream#next()
+ */
+ @Override
+ public final boolean incrementToken() throws IOException {
+ if (tokens != null && tokens.hasNext()){
+ AttributeSource.State state = tokens.next();
+ restoreState(state);
+ return true;
+ }
+ clearAttributes();
+ int tokenType = scanner.getNextToken();
+
+ if (tokenType == WikipediaTokenizerImpl.YYEOF) {
+ return false;
+ }
+ String type = WikipediaTokenizerImpl.TOKEN_TYPES[tokenType];
+ if (tokenOutput == TOKENS_ONLY || untokenizedTypes.contains(type) == false){
+ setupToken();
+ } else if (tokenOutput == UNTOKENIZED_ONLY && untokenizedTypes.contains(type) == true){
+ collapseTokens(tokenType);
+
+ }
+ else if (tokenOutput == BOTH){
+ //collapse into a single token, add it to tokens AND output the individual tokens
+ //output the untokenized Token first
+ collapseAndSaveTokens(tokenType, type);
+ }
+ posIncrAtt.setPositionIncrement(scanner.getPositionIncrement());
+ typeAtt.setType(type);
+ return true;
+ }
+
+ private void collapseAndSaveTokens(int tokenType, String type) throws IOException {
+ //collapse
+ StringBuilder buffer = new StringBuilder(32);
+ int numAdded = scanner.setText(buffer);
+ //TODO: how to know how much whitespace to add
+ int theStart = scanner.yychar();
+ int lastPos = theStart + numAdded;
+ int tmpTokType;
+ int numSeen = 0;
+ List<AttributeSource.State> tmp = new ArrayList<AttributeSource.State>();
+ setupSavedToken(0, type);
+ tmp.add(captureState());
+ //while we can get a token and that token is the same type and we have not transitioned to a new wiki-item of the same type
+ while ((tmpTokType = scanner.getNextToken()) != WikipediaTokenizerImpl.YYEOF && tmpTokType == tokenType && scanner.getNumWikiTokensSeen() > numSeen){
+ int currPos = scanner.yychar();
+ //append whitespace
+ for (int i = 0; i < (currPos - lastPos); i++){
+ buffer.append(' ');
+ }
+ numAdded = scanner.setText(buffer);
+ setupSavedToken(scanner.getPositionIncrement(), type);
+ tmp.add(captureState());
+ numSeen++;
+ lastPos = currPos + numAdded;
+ }
+ //trim the buffer
+ // TODO: this is inefficient
+ String s = buffer.toString().trim();
+ termAtt.setEmpty().append(s);
+ offsetAtt.setOffset(correctOffset(theStart), correctOffset(theStart + s.length()));
+ flagsAtt.setFlags(UNTOKENIZED_TOKEN_FLAG);
+ //The way the loop is written, we will have proceeded to the next token. We need to pushback the scanner to lastPos
+ if (tmpTokType != WikipediaTokenizerImpl.YYEOF){
+ scanner.yypushback(scanner.yylength());
+ }
+ tokens = tmp.iterator();
+ }
+
+ private void setupSavedToken(int positionInc, String type){
+ setupToken();
+ posIncrAtt.setPositionIncrement(positionInc);
+ typeAtt.setType(type);
+ }
+
+ private void collapseTokens(int tokenType) throws IOException {
+ //collapse
+ StringBuilder buffer = new StringBuilder(32);
+ int numAdded = scanner.setText(buffer);
+ //TODO: how to know how much whitespace to add
+ int theStart = scanner.yychar();
+ int lastPos = theStart + numAdded;
+ int tmpTokType;
+ int numSeen = 0;
+ //while we can get a token and that token is the same type and we have not transitioned to a new wiki-item of the same type
+ while ((tmpTokType = scanner.getNextToken()) != WikipediaTokenizerImpl.YYEOF && tmpTokType == tokenType && scanner.getNumWikiTokensSeen() > numSeen){
+ int currPos = scanner.yychar();
+ //append whitespace
+ for (int i = 0; i < (currPos - lastPos); i++){
+ buffer.append(' ');
+ }
+ numAdded = scanner.setText(buffer);
+ numSeen++;
+ lastPos = currPos + numAdded;
+ }
+ //trim the buffer
+ // TODO: this is inefficient
+ String s = buffer.toString().trim();
+ termAtt.setEmpty().append(s);
+ offsetAtt.setOffset(correctOffset(theStart), correctOffset(theStart + s.length()));
+ flagsAtt.setFlags(UNTOKENIZED_TOKEN_FLAG);
+ //The way the loop is written, we will have proceeded to the next token. We need to pushback the scanner to lastPos
+ if (tmpTokType != WikipediaTokenizerImpl.YYEOF){
+ scanner.yypushback(scanner.yylength());
+ } else {
+ tokens = null;
+ }
+ }
+
+ private void setupToken() {
+ scanner.getText(termAtt);
+ final int start = scanner.yychar();
+ offsetAtt.setOffset(correctOffset(start), correctOffset(start + termAtt.length()));
+ }
+
+ /*
+ * (non-Javadoc)
+ *
+ * @see org.apache.lucene.analysis.TokenStream#reset()
+ */
+ @Override
+ public void reset() throws IOException {
+ super.reset();
+ scanner.yyreset(input);
+ }
+
+ @Override
+ public void reset(Reader reader) throws IOException {
+ super.reset(reader);
+ reset();
+ }
+
+ @Override
+ public void end() throws IOException {
+ // set final offset
+ final int finalOffset = correctOffset(scanner.yychar() + scanner.yylength());
+ this.offsetAtt.setOffset(finalOffset, finalOffset);
+ }
+}
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fnp / pylucene.git / blobdiff