org.lenskit.util.keys.KeyedObjectMapBuilder.java Source code

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Here is the source code for org.lenskit.util.keys.KeyedObjectMapBuilder.java

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/*
 * LensKit, an open source recommender systems toolkit.
 * Copyright 2010-2014 LensKit Contributors.  See CONTRIBUTORS.md.
 * Work on LensKit has been funded by the National Science Foundation under
 * grants IIS 05-34939, 08-08692, 08-12148, and 10-17697.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
package org.lenskit.util.keys;

import com.google.common.collect.ImmutableList;

/**
 * Builder for keyed object maps.
 * @param <T> The type of item.
 */
public class KeyedObjectMapBuilder<T> {
    private final KeyExtractor<? super T> extractor;
    private final ImmutableList.Builder<T> builder;

    public KeyedObjectMapBuilder(KeyExtractor<? super T> ex) {
        extractor = ex;
        builder = ImmutableList.builder();
    }

    public KeyedObjectMapBuilder<T> add(T item) {
        builder.add(item);
        return this;
    }

    public KeyedObjectMapBuilder<T> addAll(Iterable<? extends T> items) {
        builder.addAll(items);
        return this;
    }

    public KeyedObjectMapBuilder<T> add(T... items) {
        builder.add(items);
        return this;
    }

    public KeyedObjectMap<T> build() {
        return new KeyedObjectMap<>(builder.build(), extractor);
    }
}