001/*
002 * Copyright (c) 2015-2020, Oracle and/or its affiliates. All rights reserved.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.tribuo.data.text;
018
019import com.oracle.labs.mlrg.olcut.config.Configurable;
020import com.oracle.labs.mlrg.olcut.provenance.ConfiguredObjectProvenance;
021import com.oracle.labs.mlrg.olcut.provenance.Provenancable;
022import org.tribuo.Feature;
023
024import java.util.List;
025
026/**
027 * A feature transformer maps a list of features to a new list of features
028 * Useful for example to apply the hashing trick to a set of features
029 */
030public interface FeatureTransformer extends Configurable, Provenancable<ConfiguredObjectProvenance> {
031
032    /**
033     * Transforms features into a new list of features
034     * @param tag The feature name tag.
035     * @param features The features to transform.
036     * @return The transformed features.
037     */
038    public List<Feature> map(String tag, List<Feature> features);
039    
040}