blue.lapis.pore.util.PoreCollections.java Source code

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Here is the source code for blue.lapis.pore.util.PoreCollections.java

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/*
 * Pore
 * Copyright (c) 2014-2015, Lapis <https://github.com/LapisBlue>
 *
 * The MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package blue.lapis.pore.util;

import com.google.common.base.Function;
import com.google.common.collect.Collections2;
import com.google.common.collect.Lists;

import java.util.Collection;
import java.util.List;

public final class PoreCollections {

    private PoreCollections() {
    }

    public static <F, T> Collection<T> transform(Collection<F> from, Function<? super F, T> function) {
        if (from instanceof List) {
            return Lists.transform((List<F>) from, function);
        }
        return Collections2.transform(from, function);
    }

    public static <F, T> List<T> transformToList(Collection<F> from, Function<? super F, ? extends T> function) {
        // If we have a list already we can transform it directly
        if (from instanceof List) {
            return Lists.transform((List<F>) from, function);
        }

        // There is no other good way than copying everything, meh
        List<T> result = Lists.newArrayListWithCapacity(from.size());
        for (F element : from) {
            result.add(function.apply(element));
        }
        return result;
    }
}