package org.apache.lucene.sandbox.queries.regex;
import org.apache.lucene.util.BytesRef;
/*
* 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.
*/
/**
* Defines basic operations needed by {@link RegexQuery} for a regular
* expression implementation.
*/
public interface RegexCapabilities {
/**
* Called by the constructor of {@link RegexTermsEnum} allowing
* implementations to cache a compiled version of the regular
* expression pattern.
*
* @param pattern regular expression pattern
*/
public RegexMatcher compile(String pattern);
/**
* Interface for basic regex matching.
* <p>
* Implementations return true for {@link #match} if the term
* matches the regex.
* <p>
* Implementing {@link #prefix()} can restrict the TermsEnum to only
* a subset of terms when the regular expression matches a constant
* prefix.
* <p>
* NOTE: implementations cannot seek.
*/
public interface RegexMatcher {
/**
*
* @param term The term in bytes.
* @return true if string matches the pattern last passed to {@link #compile}.
*/
public boolean match(BytesRef term);
/**
* A wise prefix implementation can reduce the term enumeration (and thus increase performance)
* of RegexQuery dramatically!
*
* @return static non-regex prefix of the pattern last passed to {@link #compile}. May return null.
*/
public String prefix();
}
}