Lists.java

/**
 * Licensed to The Apereo Foundation under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 *
 * The Apereo Foundation licenses this file to you under the Educational
 * Community 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://opensource.org/licenses/ecl2.txt
 *
 * 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.opencastproject.fun.juc;

import java.util.ArrayList;
import java.util.List;

/** Functions for {@link List}s. */
public final class Lists {
  private Lists() {
  }

  /**
   * Create a new immutable list prepending <code>h</code> to list <code>t</code>.
   * <p>
   * Since the implementation is based on the Java Collection classes it cannot make any assumptions about the
   * immutability of <code>t</code> and therefore has to copy it into a new list. Use with care.
   */
  public static <A> List<A> cons(A h, List<? extends A> t) {
    final List<A> a = new ArrayList<A>(t.size() + 1);
    a.add(h);
    a.addAll(t);
    return Immutables.mk(a);
  }
}