001/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
002 *
003 * Copyright © 2025 microBean™.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
006 * the License. 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 distributed under the License is distributed on
011 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
012 * specific language governing permissions and limitations under the License.
013 */
014package org.microbean.attributes;
015
016import java.util.List;
017
018import java.lang.constant.ClassDesc;
019import java.lang.constant.DynamicConstantDesc;
020import java.lang.constant.MethodHandleDesc;
021import java.lang.constant.MethodTypeDesc;
022
023import java.util.Optional;
024
025import org.microbean.constant.Constables;
026
027import static java.lang.constant.ConstantDescs.BSM_INVOKE;
028import static java.lang.constant.ConstantDescs.CD_List;
029import static java.lang.constant.DirectMethodHandleDesc.Kind.STATIC;
030
031/**
032 * A {@link Value} holding other {@link Value}s.
033 *
034 * @param <T> the type of the {@link Value}s
035 *
036 * @param value a non-{@code null} {@link List} of {@link Value}s
037 *
038 * @author <a href="https://about.me/lairdnelson" target="_top">Laird Nelson</a>
039 */
040public final record ListValue<T extends Value<T>>(List<T> value) implements Value<ListValue<T>> {
041
042  /**
043   * Creates a new {@link ListValue}.
044   *
045   * @param value a non-{@code null} {@link List} of {@link Value}s
046   *
047   * @exception NullPointerException if {@code value} is {@code null}
048   */
049  public ListValue {
050    value = List.copyOf(value);
051  }
052
053  @Override // Comparable<ListValue<T>>
054  public final int compareTo(final ListValue<T> other) {
055    if (other == null) {
056      return -1;
057    } else if (this.equals(other)) {
058      return 0;
059    }
060    return this.toString().compareTo(other.toString());
061  }
062
063  @Override // Constable
064  public final Optional<DynamicConstantDesc<ListValue<T>>> describeConstable() {
065    final ClassDesc me = ClassDesc.of(this.getClass().getName());
066    return Constables.describeConstable(this.value())
067      .map(valueDesc -> DynamicConstantDesc.of(BSM_INVOKE,
068                                               MethodHandleDesc.ofMethod(STATIC,
069                                                                         me,
070                                                                         "of",
071                                                                         MethodTypeDesc.of(me,
072                                                                                           CD_List)),
073                                               valueDesc));
074  }
075
076  @Override // Record
077  public final boolean equals(final Object other) {
078    return
079      other == this ||
080      // Follow java.lang.annotation.Annotation requirements.
081      other != null && other.getClass() == this.getClass() && this.value().equals(((ListValue<?>)other).value());
082  }
083
084  @Override // Record
085  public final int hashCode() {
086    // Follow java.lang.annotation.Annotation requirements.
087    return this.value().hashCode();
088  }
089
090  @Override // Record
091  public final String toString() {
092    return this.value().toString();
093  }
094
095  /**
096   * Returns a {@link ListValue} suitable for the supplied argument.
097   *
098   * @param <T> the type of {@link Value} held by the returned {@link ListValue}
099   *
100   * @param value a non-{@code null} {@link List} of suitably-typed {@link Value}s
101   *
102   * @return a non-{@code null} {@link ListValue}
103   *
104   * @exception NullPointerException if {@code value} is {@code null}
105   */
106  @SuppressWarnings("unchecked")
107  // Called by #describeConstable()
108  public static final <T extends Value<T>> ListValue<T> of(final List<T> value) {
109    return new ListValue<>(value);
110  }
111
112}