net.hydromatic.morel.util.ComparableSingletonList Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of morel Show documentation

Standard ML interpreter, with relational extensions, implemented in Java

There is a newer version: 0.7.0

/*
 * Licensed to Julian Hyde under one or more contributor license
 * agreements.  See the NOTICE file distributed with this work
 * for additional information regarding copyright ownership.
 * Julian Hyde 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 net.hydromatic.morel.util;

import java.util.AbstractList;
import java.util.Objects;

/** A comparable singleton list.
 *
 * @param  Element type */
public class ComparableSingletonList>
    extends AbstractList
    implements Comparable> {
  private final E element;

  ComparableSingletonList(E element) {
    this.element = Objects.requireNonNull(element);
  }

  /** Creates a ComparableSingletonList. */
  public static > ComparableSingletonList of(E e) {
    return new ComparableSingletonList<>(e);
  }

  @Override public E get(int index) {
    assert index == 0;
    return element;
  }

  @Override public int size() {
    return 1;
  }

  @Override public int compareTo(ComparableSingletonList o) {
    return element.compareTo(o.element);
  }
}

// End ComparableSingletonList.java