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Java 1.8+ Library with tons of utility classes required in all projects
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/*
 * Copyright (C) 2014-2024 Philip Helger (www.helger.com)
 * philip[at]helger[dot]com
 *
 * Licensed 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 com.helger.commons.collection;

import java.util.Collection;
import java.util.function.Function;
import java.util.function.Predicate;

import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.Immutable;

import com.helger.commons.annotation.ReturnsMutableCopy;

@Immutable
public final class StackHelper
{
  private StackHelper ()
  {}

  @Nonnull
  @ReturnsMutableCopy
  public static  NonBlockingStack  newStack (@Nonnegative final int nInitialCapacity)
  {
    return new NonBlockingStack <> (nInitialCapacity);
  }

  @Nonnull
  @ReturnsMutableCopy
  public static  NonBlockingStack  newStack ()
  {
    return new NonBlockingStack <> ();
  }

  @Nonnull
  @ReturnsMutableCopy
  public static  NonBlockingStack  newStackMapped (@Nullable final Collection  aCollection,
                                                                              @Nonnull final Function  aMapper)
  {
    if (CollectionHelper.isEmpty (aCollection))
      return newStack (0);
    final NonBlockingStack  ret = newStack (aCollection.size ());
    for (final SRCTYPE aValue : aCollection)
      ret.push (aMapper.apply (aValue));
    return ret;
  }

  @Nonnull
  @ReturnsMutableCopy
  public static  NonBlockingStack  newStackMapped (@Nullable final SRCTYPE [] aArray,
                                                                              @Nonnull final Function  aMapper)
  {
    if (ArrayHelper.isEmpty (aArray))
      return newStack (0);
    final NonBlockingStack  ret = newStack (aArray.length);
    for (final SRCTYPE aValue : aArray)
      ret.push (aMapper.apply (aValue));
    return ret;
  }

  /**
   * Create a new stack with a single element.
   *
   * @param 
   *        The type of elements contained in the stack.
   * @param aValue
   *        The value to push. Maybe null.
   * @return A non-null stack.
   */
  @Nonnull
  @ReturnsMutableCopy
  public static  NonBlockingStack  newStack (@Nullable final ELEMENTTYPE aValue)
  {
    final NonBlockingStack  ret = newStack ();
    ret.push (aValue);
    return ret;
  }

  /**
   * Create a new stack from the given array.
   *
   * @param 
   *        The type of elements contained in the stack.
   * @param aValues
   *        The values that are to be pushed on the stack. The last element will
   *        be the top element on the stack. May not be null .
   * @return A non-null stack object.
   */
  @Nonnull
  @ReturnsMutableCopy
  @SafeVarargs
  public static  NonBlockingStack  newStack (@Nullable final ELEMENTTYPE... aValues)
  {
    return new NonBlockingStack <> (aValues);
  }

  @Nonnull
  @ReturnsMutableCopy
  public static  NonBlockingStack  newStack (@Nullable final Collection  aCollection,
                                                                       @Nonnull final Predicate  aFilter)
  {
    if (CollectionHelper.isEmpty (aCollection))
      return newStack (0);
    final NonBlockingStack  ret = newStack (aCollection.size ());
    CollectionHelper.findAll (aCollection, aFilter, ret::add);
    return ret;
  }

  /**
   * Create a new stack from the given collection.
   *
   * @param 
   *        The type of elements contained in the stack.
   * @param aValues
   *        The values that are to be pushed on the stack. The last element will
   *        be the top element on the stack. May not be null .
   * @return A non-null stack object.
   */
  @Nonnull
  @ReturnsMutableCopy
  public static  NonBlockingStack  newStack (@Nullable final Collection  aValues)
  {
    return new NonBlockingStack <> (aValues);
  }

  @Nullable
  @ReturnsMutableCopy
  public static  NonBlockingStack  getStackCopyWithoutTop (@Nullable final NonBlockingStack  aStack)
  {
    if (CollectionHelper.isEmpty (aStack))
      return null;

    final NonBlockingStack  ret = new NonBlockingStack <> (aStack);
    ret.pop ();
    return ret;
  }
}