package org.apache.lucene.search.regex;
/**
* Copyright 2006 The Apache Software Foundation
*
* Licensed 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 org.apache.lucene.search.FilteredTermEnum;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.Term;
import java.io.IOException;
/**
* Subclass of FilteredTermEnum for enumerating all terms that match the
* specified regular expression term using the specified regular expression
* implementation.
* <p>
* Term enumerations are always ordered by Term.compareTo(). Each term in
* the enumeration is greater than all that precede it.
*/
public class RegexTermEnum extends FilteredTermEnum {
private String field = "";
private String pre = "";
private boolean endEnum = false;
private RegexCapabilities regexImpl;
public RegexTermEnum(IndexReader reader, Term term, RegexCapabilities regexImpl) throws IOException {
super();
field = term.field();
String text = term.text();
this.regexImpl = regexImpl;
regexImpl.compile(text);
pre = regexImpl.prefix();
if (pre == null) pre = "";
setEnum(reader.terms(new Term(term.field(), pre)));
}
protected final boolean termCompare(Term term) {
if (field == term.field()) {
String searchText = term.text();
if (searchText.startsWith(pre)) {
return regexImpl.match(searchText);
}
}
endEnum = true;
return false;
}
public final float difference() {
// TODO: adjust difference based on distance of searchTerm.text() and term().text()
return 1.0f;
}
public final boolean endEnum() {
return endEnum;
}
public void close() throws IOException {
super.close();
field = null;
}
}
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