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Posted to commits@lucene.apache.org by mi...@apache.org on 2013/09/12 23:26:29 UTC
svn commit: r1522733 - in /lucene/dev/trunk/lucene: CHANGES.txt
core/src/java/org/apache/lucene/search/FuzzyQuery.java
core/src/test/org/apache/lucene/search/FuzzyTermOnShortTermsTest.java
Author: mikemccand
Date: Thu Sep 12 21:26:29 2013
New Revision: 1522733
URL: http://svn.apache.org/r1522733
Log:
LUCENE-5206: fix javadocs to clarify FuzzyQuery's unexpected behaviour on short terms
Added:
lucene/dev/trunk/lucene/core/src/test/org/apache/lucene/search/FuzzyTermOnShortTermsTest.java (with props)
Modified:
lucene/dev/trunk/lucene/CHANGES.txt
lucene/dev/trunk/lucene/core/src/java/org/apache/lucene/search/FuzzyQuery.java
Modified: lucene/dev/trunk/lucene/CHANGES.txt
URL: http://svn.apache.org/viewvc/lucene/dev/trunk/lucene/CHANGES.txt?rev=1522733&r1=1522732&r2=1522733&view=diff
==============================================================================
--- lucene/dev/trunk/lucene/CHANGES.txt (original)
+++ lucene/dev/trunk/lucene/CHANGES.txt Thu Sep 12 21:26:29 2013
@@ -63,6 +63,11 @@ Bug Fixes
* LUCENE-4998: Fixed a few places to pass IOContext.READONCE instead
of IOContext.READ (Shikhar Bhushan via Mike McCandless)
+Documentation
+
+* LUCENE-5206: Clarify FuzzyQuery's unexpected behavior on short
+ terms. (Tim Allison via Mike McCandless)
+
Changes in backwards compatibility policy
* LUCENE-5204: Directory doesn't have default implementations for
Modified: lucene/dev/trunk/lucene/core/src/java/org/apache/lucene/search/FuzzyQuery.java
URL: http://svn.apache.org/viewvc/lucene/dev/trunk/lucene/core/src/java/org/apache/lucene/search/FuzzyQuery.java?rev=1522733&r1=1522732&r2=1522733&view=diff
==============================================================================
--- lucene/dev/trunk/lucene/core/src/java/org/apache/lucene/search/FuzzyQuery.java (original)
+++ lucene/dev/trunk/lucene/core/src/java/org/apache/lucene/search/FuzzyQuery.java Thu Sep 12 21:26:29 2013
@@ -43,6 +43,13 @@ import org.apache.lucene.util.automaton.
* will match a significant amount of the term dictionary. If you really want this, consider
* using an n-gram indexing technique (such as the SpellChecker in the
* <a href="{@docRoot}/../suggest/overview-summary.html">suggest module</a>) instead.
+ *
+ * <p>NOTE: terms of length 1 or 2 will sometimes not match because of how the scaled
+ * distance between two terms is computed. For a term to match, the edit distance between
+ * the terms must be less than the minimum length term (either the input term, or
+ * the candidate term). For example, FuzzyQuery on term "abcd" with maxEdits=2 will
+ * not match an indexed term "ab", and FuzzyQuery on term "a" with maxEdits=2 will not
+ * match an indexed term "abc".
*/
public class FuzzyQuery extends MultiTermQuery {
Added: lucene/dev/trunk/lucene/core/src/test/org/apache/lucene/search/FuzzyTermOnShortTermsTest.java
URL: http://svn.apache.org/viewvc/lucene/dev/trunk/lucene/core/src/test/org/apache/lucene/search/FuzzyTermOnShortTermsTest.java?rev=1522733&view=auto
==============================================================================
--- lucene/dev/trunk/lucene/core/src/test/org/apache/lucene/search/FuzzyTermOnShortTermsTest.java (added)
+++ lucene/dev/trunk/lucene/core/src/test/org/apache/lucene/search/FuzzyTermOnShortTermsTest.java Thu Sep 12 21:26:29 2013
@@ -0,0 +1,99 @@
+/*
+ * 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.search;
+
+
+import java.io.IOException;
+import java.io.Reader;
+
+import org.apache.lucene.analysis.Analyzer;
+import org.apache.lucene.analysis.MockTokenizer;
+import org.apache.lucene.analysis.Tokenizer;
+import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
+import org.apache.lucene.index.DirectoryReader;
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.RandomIndexWriter;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.store.Directory;
+import org.apache.lucene.util.LuceneTestCase;
+import org.apache.lucene.util._TestUtil;
+import org.junit.Test;
+
+
+public class FuzzyTermOnShortTermsTest extends LuceneTestCase {
+ private final static String FIELD = "field";
+
+ @Test
+ public void test() throws Exception {
+ // proves rule that edit distance between the two terms
+ // must be > smaller term for there to be a match
+ Analyzer a = getAnalyzer();
+ //these work
+ countHits(a, new String[]{"abc"}, new FuzzyQuery(new Term(FIELD, "ab"), 1), 1);
+ countHits(a, new String[]{"ab"}, new FuzzyQuery(new Term(FIELD, "abc"), 1), 1);
+
+ countHits(a, new String[]{"abcde"}, new FuzzyQuery(new Term(FIELD, "abc"), 2), 1);
+ countHits(a, new String[]{"abc"}, new FuzzyQuery(new Term(FIELD, "abcde"), 2), 1);
+
+ //these don't
+ countHits(a, new String[]{"ab"}, new FuzzyQuery(new Term(FIELD, "a"), 1), 0);
+ countHits(a, new String[]{"a"}, new FuzzyQuery(new Term(FIELD, "ab"), 1), 0);
+
+ countHits(a, new String[]{"abc"}, new FuzzyQuery(new Term(FIELD, "a"), 2), 0);
+ countHits(a, new String[]{"a"}, new FuzzyQuery(new Term(FIELD, "abc"), 2), 0);
+
+ countHits(a, new String[]{"abcd"}, new FuzzyQuery(new Term(FIELD, "ab"), 2), 0);
+ countHits(a, new String[]{"ab"}, new FuzzyQuery(new Term(FIELD, "abcd"), 2), 0);
+ }
+
+ private void countHits(Analyzer analyzer, String[] docs, Query q, int expected) throws Exception {
+ Directory d = getDirectory(analyzer, docs);
+ IndexReader r = DirectoryReader.open(d);
+ IndexSearcher s = new IndexSearcher(r);
+ TotalHitCountCollector c = new TotalHitCountCollector();
+ s.search(q, c);
+ assertEquals(q.toString(), expected, c.getTotalHits());
+ r.close();
+ d.close();
+ }
+
+ public static Analyzer getAnalyzer(){
+ return new Analyzer() {
+ @Override
+ public TokenStreamComponents createComponents(String fieldName, Reader reader) {
+ Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.SIMPLE, true);
+ return new TokenStreamComponents(tokenizer, tokenizer);
+ }
+ };
+ }
+ public static Directory getDirectory(Analyzer analyzer, String[] vals) throws IOException{
+ Directory directory = newDirectory();
+ RandomIndexWriter writer = new RandomIndexWriter(random(), directory,
+ newIndexWriterConfig(TEST_VERSION_CURRENT, analyzer)
+ .setMaxBufferedDocs(_TestUtil.nextInt(random(), 100, 1000)).setMergePolicy(newLogMergePolicy()));
+
+ for (String s : vals){
+ Document d = new Document();
+ d.add(newTextField(FIELD, s, Field.Store.YES));
+ writer.addDocument(d);
+
+ }
+ writer.close();
+ return directory;
+ }
+}