/*
* 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.classification.document;
import java.io.IOException;
import java.util.List;
import org.apache.lucene.classification.ClassificationResult;
import org.apache.lucene.document.Document;
/**
* A classifier, see <code>http://en.wikipedia.org/wiki/Classifier_(mathematics)</code>, which assign classes of type
* <code>T</code> to a {@link org.apache.lucene.document.Document}s
*
* @lucene.experimental
*/
public interface DocumentClassifier<T> {
/**
* Assign a class (with score) to the given {@link org.apache.lucene.document.Document}
*
* @param document a {@link org.apache.lucene.document.Document} to be classified. Fields are considered features for the classification.
* @return a {@link org.apache.lucene.classification.ClassificationResult} holding assigned class of type <code>T</code> and score
* @throws java.io.IOException If there is a low-level I/O error.
*/
ClassificationResult<T> assignClass(Document document) throws IOException;
/**
* Get all the classes (sorted by score, descending) assigned to the given {@link org.apache.lucene.document.Document}.
*
* @param document a {@link org.apache.lucene.document.Document} to be classified. Fields are considered features for the classification.
* @return the whole list of {@link org.apache.lucene.classification.ClassificationResult}, the classes and scores. Returns <code>null</code> if the classifier can't make lists.
* @throws java.io.IOException If there is a low-level I/O error.
*/
List<ClassificationResult<T>> getClasses(Document document) throws IOException;
/**
* Get the first <code>max</code> classes (sorted by score, descending) assigned to the given text String.
*
* @param document a {@link org.apache.lucene.document.Document} to be classified. Fields are considered features for the classification.
* @param max the number of return list elements
* @return the whole list of {@link org.apache.lucene.classification.ClassificationResult}, the classes and scores. Cut for "max" number of elements. Returns <code>null</code> if the classifier can't make lists.
* @throws java.io.IOException If there is a low-level I/O error.
*/
List<ClassificationResult<T>> getClasses(Document document, int max) throws IOException;
}