// Copyright (c) 2017, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
package com.android.tools.r8.ir.analysis.type;

import com.android.tools.r8.graph.AppInfo;
import com.android.tools.r8.graph.DexType;

public class BottomTypeLatticeElement extends TypeLatticeElement {
  private static final BottomTypeLatticeElement INSTANCE = new BottomTypeLatticeElement();

  private BottomTypeLatticeElement() {
    super(true);
  }

  @Override
  public TypeLatticeElement asNullable() {
    return this;
  }

  static BottomTypeLatticeElement getInstance() {
    return INSTANCE;
  }

  @Override
  public boolean isBottom() {
    return true;
  }

  @Override
  public TypeLatticeElement arrayGet(AppInfo appInfo) {
    return this;
  }

  @Override
  public TypeLatticeElement checkCast(AppInfo appInfo, DexType castType) {
    return this;
  }

  @Override
  public String toString() {
    return "BOTTOM (empty)";
  }

  @Override
  public boolean equals(Object o) {
    return this == o;
  }

  @Override
  public int hashCode() {
    return System.identityHashCode(INSTANCE);
  }
}