package org.apache.lucene.analysis.synonym;
/*
* 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.
*/
import java.io.IOException;
import java.io.LineNumberReader;
import java.io.Reader;
import java.text.ParseException;
import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.util.CharsRef;
/**
* Parser for wordnet prolog format
* <p>
* See http://wordnet.princeton.edu/man/prologdb.5WN.html for a description of the format.
* @lucene.experimental
*/
// TODO: allow you to specify syntactic categories (e.g. just nouns, etc)
public class WordnetSynonymParser extends SynonymMap.Builder {
private final boolean expand;
private final Analyzer analyzer;
public WordnetSynonymParser(boolean dedup, boolean expand, Analyzer analyzer) {
super(dedup);
this.expand = expand;
this.analyzer = analyzer;
}
public void add(Reader in) throws IOException, ParseException {
LineNumberReader br = new LineNumberReader(in);
try {
String line = null;
String lastSynSetID = "";
CharsRef synset[] = new CharsRef[8];
int synsetSize = 0;
while ((line = br.readLine()) != null) {
String synSetID = line.substring(2, 11);
if (!synSetID.equals(lastSynSetID)) {
addInternal(synset, synsetSize);
synsetSize = 0;
}
if (synset.length <= synsetSize+1) {
CharsRef larger[] = new CharsRef[synset.length * 2];
System.arraycopy(synset, 0, larger, 0, synsetSize);
synset = larger;
}
synset[synsetSize] = parseSynonym(line, synset[synsetSize]);
synsetSize++;
lastSynSetID = synSetID;
}
// final synset in the file
addInternal(synset, synsetSize);
} catch (IllegalArgumentException e) {
ParseException ex = new ParseException("Invalid synonym rule at line " + br.getLineNumber(), 0);
ex.initCause(e);
throw ex;
} finally {
br.close();
}
}
private CharsRef parseSynonym(String line, CharsRef reuse) throws IOException {
if (reuse == null) {
reuse = new CharsRef(8);
}
int start = line.indexOf('\'')+1;
int end = line.lastIndexOf('\'');
String text = line.substring(start, end).replace("''", "'");
return analyze(analyzer, text, reuse);
}
private void addInternal(CharsRef synset[], int size) {
if (size <= 1) {
return; // nothing to do
}
if (expand) {
for (int i = 0; i < size; i++) {
for (int j = 0; j < size; j++) {
add(synset[i], synset[j], false);
}
}
} else {
for (int i = 0; i < size; i++) {
add(synset[i], synset[0], false);
}
}
}
}