/*
 
* Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
 
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 
*
 
* This code is free software; you can redistribute it and/or modify it
 
* under the terms of the GNU General Public License version 2 only, as
 
* published by the Free Software Foundation.
  
Oracle designates this
 
* particular file as subject to the "Classpath" exception as provided
 
* by Oracle in the LICENSE file that accompanied this code.
 
*
 
* This code is distributed in the hope that it will be useful, but WITHOUT
 
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 
* FITNESS FOR A PARTICULAR PURPOSE.
  
See the GNU General Public License
 
* version 2 for more details (a copy is included in the LICENSE file that
 
* accompanied this code).
 
*
 
* You should have received a copy of the GNU General Public License version
 
* 2 along with this work; if not, write to the Free Software Foundation,
 
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 
*
 
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 
* or visit www.oracle.com if you need additional information or have any
 
* questions.
 
*/

package java.util;

import java.util.function.UnaryOperator;

/**
 
* An ordered collection (also known as a <i>sequence</i>).
  
The user of this
 
* interface has precise control over where in the list each element is
 
* inserted.
  
The user can access elements by their integer index (position in
 
* the list), and search for elements in the list.<p>
 
*
 
* Unlike sets, lists typically allow duplicate elements.
  
More formally,
 
* lists typically allow pairs of elements <tt>e1</tt> and <tt>e2</tt>
 
* such that <tt>e1.equals(e2)</tt>, and they typically allow multiple
 
* null elements if they allow null elements at all.
  
It is not inconceivable
 
* that someone might wish to implement a list that prohibits duplicates, by
 
* throwing runtime exceptions when the user attempts to insert them, but we
 
* expect this usage to be rare.<p>
 
*
 
* The <tt>List</tt> interface places additional stipulations, beyond those
 
* specified in the <tt>Collection</tt> interface, on the contracts of the
 
* <tt>iterator</tt>, <tt>add</tt>, <tt>remove</tt>, <tt>equals</tt>, and
 
* <tt>hashCode</tt> methods.
  
Declarations for other inherited methods are
 
* also included here for convenience.<p>
 
*
 
* The <tt>List</tt> interface provides four methods for positional (indexed)
 
* access to list elements.
  
Lists (like Java arrays) are zero based.Note
 
* that these operations may execute in time proportional to the index value
 
* for some implementations (the <tt>LinkedList</tt> class, for
 
* example). Thus, iterating over the elements in a list is typically
 
* preferable to indexing through it if the caller does not know the
 
* implementation.<p>
 
*
 
* The <tt>List</tt> interface provides a special iterator, called a
 
* <tt>ListIterator</tt>, that allows element insertion and replacement, and
 
* bidirectional access in addition to the normal operations that the
 
* <tt>Iterator</tt> interface provides.
  
A method is provided to obtain a
 
* list iterator that starts at a specified position in the list.<p>
 
*
 
* The <tt>List</tt> interface provides two methods to search for a specified
 
* object.
  
From a performance standpoint, these methods should be used with
 
* caution.
  
In many implementations they will perform costly linear
 
* searches.<p>
 
*
 
* The <tt>List</tt> interface provides two methods to efficiently insert and
 
* remove multiple elements at an arbitrary point in the list.<p>
 
*
 
* Note: While it is permissible for lists to contain themselves as elements,
 
* extreme caution is advised: the <tt>equals</tt> and <tt>hashCode</tt>
 
* methods are no longer well defined on such a list.
 
*
 
* <p>Some list implementations have restrictions on the elements that
 
* they may contain.
  
For example, some implementations prohibit null elements,
 
* and some have restrictions on the types of their elements.
  
Attempting to
 
* add an ineligible element throws an unchecked exception, typically
 
* <tt>NullPointerException</tt> or <tt>ClassCastException</tt>.
  
Attempting
 
* to query the presence of an ineligible element may throw an exception,
 
* or it may simply return false; some implementations will exhibit the former
 
* behavior and some will exhibit the latter.
  
More generally, attempting an
 
* operation on an ineligible element whose completion would not result in
 
* the insertion of an ineligible element into the list may throw an
 
* exception or it may succeed, at the option of the implementation.
 
* Such exceptions are marked as "optional" in the specification for this
 
* interface.
 
*
 
* <p>This interface is a member of the
 
* <a href="{@docRoot}/../technotes/guides/collections/index.html">
 
* Java Collections Framework</a>.
 
*
 
* @param <E> the type of elements in this list
 
*
 
* @author
  
Josh Bloch
 
* @author
  
Neal Gafter
 
* @see Collection
 
* @see Set
 
* @see ArrayList
 
* @see LinkedList
 
* @see Vector
 
* @see Arrays#asList(Object[])
 
* @see Collections#nCopies(int, Object)
 
* @see Collections#EMPTY_LIST
 
* @see AbstractList
 
* @see AbstractSequentialList
 
* @since 1.2
 
*/


public interface List<E> extends Collection<E> {
    
// Query Operations

    
/**
     
* Returns the number of elements in this list.
  
If this list contains
     
* more than <tt>Integer.MAX_VALUE</tt> elements, returns
     
* <tt>Integer.MAX_VALUE</tt>.
     
*
     
* @return the number of elements in this list
     
*/

    
int size();

    
/**
     
* Returns <tt>true</tt> if this list contains no elements.
     
*
     
* @return <tt>true</tt> if this list contains no elements
     
*/

    
boolean isEmpty();

    
/**
     
* Returns <tt>true</tt> if this list contains the specified element.
     
* More formally, returns <tt>true</tt> if and only if this list contains
     
* at least one element <tt>e</tt> such that
     
* <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
     
*
     
* @param o element whose presence in this list is to be tested
     
* @return <tt>true</tt> if this list contains the specified element
     
* @throws ClassCastException if the type of the specified element
     
*
         
is incompatible with this list
     
* (<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws NullPointerException if the specified element is null and this
     
*
         
list does not permit null elements
     
* (<a href="Collection.html#optional-restrictions">optional</a>)
     
*/

    
boolean contains(Object o);

    
/**
     
* Returns an iterator over the elements in this list in proper sequence.
     
*
     
* @return an iterator over the elements in this list in proper sequence
     
*/

    
Iterator<E> iterator();

    
/**
     
* Returns an array containing all of the elements in this list in proper
     
* sequence (from first to last element).
     
*
     
* <p>The returned array will be "safe" in that no references to it are
     
* maintained by this list.
  
(In other words, this method must
     
* allocate a new array even if this list is backed by an array).
     
* The caller is thus free to modify the returned array.
     
*
     
* <p>This method acts as bridge between array-based and collection-based
     
* APIs.
     
*
     
* @return an array containing all of the elements in this list in proper
     
*
         
sequence
     
* @see Arrays#asList(Object[])
     
*/

    
Object[] toArray();

    
/**
     
* Returns an array containing all of the elements in this list in
     
* proper sequence (from first to last element); the runtime type of
     
* the returned array is that of the specified array.
  
If the list fits
     
* in the specified array, it is returned therein.
  
Otherwise, a new
     
* array is allocated with the runtime type of the specified array and
     
* the size of this list.
     
*
     
* <p>If the list fits in the specified array with room to spare (i.e.,
     
* the array has more elements than the list), the element in the array
     
* immediately following the end of the list is set to <tt>null</tt>.
     
* (This is useful in determining the length of the list <i>only</i> if
     
* the caller knows that the list does not contain any null elements.)
     
*
     
* <p>Like the
 
 
method, this method acts as bridge between
     
* array-based and collection-based APIs.
  
Further, this method allows
     
* precise control over the runtime type of the output array, and may,
     
* under certain circumstances, be used to save allocation costs.
     
*
     
* <p>Suppose <tt>x</tt> is a list known to contain only strings.
     
* The following code can be used to dump the list into a newly
     
* allocated array of <tt>String</tt>:
     
*
     
* <pre>{@code
     
*String[] y = x.toArray(new String[0]);
     
* }</pre>
     
*
     
* Note that <tt>toArray(new Object[0])</tt> is identical in function to
     
* <tt>toArray()</tt>.
     
*
     
* @param a the array into which the elements of this list are to
     
*
          
be stored, if it is big enough; otherwise, a new array of the
     
*
          
same runtime type is allocated for this purpose.
     
* @return an array containing the elements of this list
     
* @throws ArrayStoreException if the runtime type of the specified array
     
*
         
is not a supertype of the runtime type of every element in
     
*
         
this list
     
* @throws NullPointerException if the specified array is null
     
*/

    
<T> T[] toArray(T[] a);


    
// Modification Operations

    
/**
     
* Appends the specified element to the end of this list (optional
     
* operation).
     
*
     
* <p>Lists that support this operation may place limitations on what
     
* elements may be added to this list.
  
In particular, some
     
* lists will refuse to add null elements, and others will impose
     
* restrictions on the type of elements that may be added.
  
List
     
* classes should clearly specify in their documentation any restrictions
     
* on what elements may be added.
     
*
     
* @param e element to be appended to this list
     
* @return <tt>true</tt> (as specified by {@link Collection#add})
     
* @throws UnsupportedOperationException if the <tt>add</tt> operation
     
*
         
is not supported by this list
     
* @throws ClassCastException if the class of the specified element
     
*
         
prevents it from being added to this list
     
* @throws NullPointerException if the specified element is null and this
     
*
         
list does not permit null elements
     
* @throws IllegalArgumentException if some property of this element
     
*
         
prevents it from being added to this list
     
*/

    
boolean add(E e);

    
/**
     
* Removes the first occurrence of the specified element from this list,
     
* if it is present (optional operation).
  
If this list does not contain
     
* the element, it is unchanged.
  
More formally, removes the element with
     
* the lowest index <tt>i</tt> such that
     
* <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>
     
* (if such an element exists).
  
Returns <tt>true</tt> if this list
     
* contained the specified element (or equivalently, if this list changed
     
* as a result of the call).
     
*
     
* @param o element to be removed from this list, if present
     
* @return <tt>true</tt> if this list contained the specified element
     
* @throws ClassCastException if the type of the specified element
     
*
         
is incompatible with this list
     
* (<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws NullPointerException if the specified element is null and this
     
*
         
list does not permit null elements
     
* (<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws UnsupportedOperationException if the <tt>remove</tt> operation
     
*
         
is not supported by this list
     
*/

    
boolean remove(Object o);


    
// Bulk Modification Operations

    
/**
     
* Returns <tt>true</tt> if this list contains all of the elements of the
     
* specified collection.
     
*
     
* @param
  
c collection to be checked for containment in this list
     
* @return <tt>true</tt> if this list contains all of the elements of the
     
*
         
specified collection
     
* @throws ClassCastException if the types of one or more elements
     
*
         
in the specified collection are incompatible with this
     
*
         
list
     
* (<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws NullPointerException if the specified collection contains one
     
*
         
or more null elements and this list does not permit null
     
*
         
elements
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>),
     
*
         
or if the specified collection is null
     
* @see #contains(Object)
     
*/

    
boolean containsAll(Collection<?> c);

    
/**
     
* Appends all of the elements in the specified collection to the end of
     
* this list, in the order that they are returned by the specified
     
* collection's iterator (optional operation).
  
The behavior of this
     
* operation is undefined if the specified collection is modified while
     
* the operation is in progress.
  
(Note that this will occur if the
     
* specified collection is this list, and it's nonempty.)
     
*
     
* @param c collection containing elements to be added to this list
     
* @return <tt>true</tt> if this list changed as a result of the call
     
* @throws UnsupportedOperationException if the <tt>addAll</tt> operation
     
*
         
is not supported by this list
     
* @throws ClassCastException if the class of an element of the specified
     
*
         
collection prevents it from being added to this list
     
* @throws NullPointerException if the specified collection contains one
     
*
         
or more null elements and this list does not permit null
     
*
         
elements, or if the specified collection is null
     
* @throws IllegalArgumentException if some property of an element of the
     
*
         
specified collection prevents it from being added to this list
     
* @see #add(Object)
     
*/

    
boolean addAll(Collection<? extends E> c);

    
/**
     
* Inserts all of the elements in the specified collection into this
     
* list at the specified position (optional operation).
  
Shifts the
     
* element currently at that position (if any) and any subsequent
     
* elements to the right (increases their indices).
  
The new elements
     
* will appear in this list in the order that they are returned by the
     
* specified collection's iterator.
  
The behavior of this operation is
     
* undefined if the specified collection is modified while the
     
* operation is in progress.
  
(Note that this will occur if the specified
     
* collection is this list, and it's nonempty.)
     
*
     
* @param index index at which to insert the first element from the
     
*
              
specified collection
     
* @param c collection containing elements to be added to this list
     
* @return <tt>true</tt> if this list changed as a result of the call
     
* @throws UnsupportedOperationException if the <tt>addAll</tt> operation
     
*
         
is not supported by this list
     
* @throws ClassCastException if the class of an element of the specified
     
*
         
collection prevents it from being added to this list
     
* @throws NullPointerException if the specified collection contains one
     
*
         
or more null elements and this list does not permit null
     
*
         
elements, or if the specified collection is null
     
* @throws IllegalArgumentException if some property of an element of the
     
*
         
specified collection prevents it from being added to this list
     
* @throws IndexOutOfBoundsException if the index is out of range
     
*
         
(<tt>index &lt; 0 || index &gt; size()</tt>)
     
*/

    
boolean addAll(int index, Collection<? extends E> c);

    
/**
     
* Removes from this list all of its elements that are contained in the
     
* specified collection (optional operation).
     
*
     
* @param c collection containing elements to be removed from this list
     
* @return <tt>true</tt> if this list changed as a result of the call
     
* @throws UnsupportedOperationException if the <tt>removeAll</tt> operation
     
*
         
is not supported by this list
     
* @throws ClassCastException if the class of an element of this list
     
*
         
is incompatible with the specified collection
     
* (<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws NullPointerException if this list contains a null element and the
     
*
         
specified collection does not permit null elements
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>),
     
*
         
or if the specified collection is null
     
* @see #remove(Object)
     
* @see #contains(Object)
     
*/

    
boolean removeAll(Collection<?> c);

    
/**
     
* Retains only the elements in this list that are contained in the
     
* specified collection (optional operation).
  
In other words, removes
     
* from this list all of its elements that are not contained in the
     
* specified collection.
     
*
     
* @param c collection containing elements to be retained in this list
     
* @return <tt>true</tt> if this list changed as a result of the call
     
* @throws UnsupportedOperationException if the <tt>retainAll</tt> operation
     
*
         
is not supported by this list
     
* @throws ClassCastException if the class of an element of this list
     
*
         
is incompatible with the specified collection
     
* (<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws NullPointerException if this list contains a null element and the
     
*
         
specified collection does not permit null elements
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>),
     
*
         
or if the specified collection is null
     
* @see #remove(Object)
     
* @see #contains(Object)
     
*/

    
boolean retainAll(Collection<?> c);

    
/**
     
* Replaces each element of this list with the result of applying the
     
* operator to that element.
  
Errors or runtime exceptions thrown by
     
* the operator are relayed to the caller.
     
*
     
* @implSpec
     
* The default implementation is equivalent to, for this {@code list}:
     
* <pre>{@code
     
*final ListIterator<E> li = list.listIterator();
     
*while (li.hasNext()) {
     
*
         
li.set(operator.apply(li.next()));
     
*}
     
* }</pre>
     
*
     
* If the list's list-iterator does not support the {@code set} operation
     
* then an {@code UnsupportedOperationException} will be thrown when
     
* replacing the first element.
     
*
     
* @param operator the operator to apply to each element
     
* @throws UnsupportedOperationException if this list is unmodifiable.
     
*
         
Implementations may throw this exception if an element
     
*
         
cannot be replaced or if, in general, modification is not
     
*
         
supported
     
* @throws NullPointerException if the specified operator is null or
     
*
         
if the operator result is a null value and this list does
     
*
         
not permit null elements
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>)
     
* @since 1.8
     
*/

    
default void replaceAll(UnaryOperator<E> operator) {
        
Objects.requireNonNull(operator);
        
final ListIterator<E> li = this.listIterator();
        
while (li.hasNext()) {
            
li.set(operator.apply(li.next()));
        
}
    
}

    
/**
     
* Sorts this list according to the order induced by the specified
     
* {@link Comparator}.
     
*
     
* <p>All elements in this list must be <i>mutually comparable</i> using the
     
* specified comparator (that is, {@code c.compare(e1, e2)} must not throw
     
* a {@code ClassCastException} for any elements {@code e1} and {@code e2}
     
* in the list).
     
*
     
* <p>If the specified comparator is {@code null} then all elements in this
     
* list must implement the {@link Comparable} interface and the elements'
     
* {@linkplain Comparable natural ordering} should be used.
     
*
     
* <p>This list must be modifiable, but need not be resizable.
     
*
     
* @implSpec
     
* The default implementation obtains an array containing all elements in
     
* this list, sorts the array, and iterates over this list resetting each
     
* element from the corresponding position in the array. (This avoids the
     
* n<sup>2</sup> log(n) performance that would result from attempting
     
* to sort a linked list in place.)
     
*
     
* @implNote
     
* This implementation is a stable, adaptive, iterative mergesort that
     
* requires far fewer than n lg(n) comparisons when the input array is
     
* partially sorted, while offering the performance of a traditional
     
* mergesort when the input array is randomly ordered.
  
If the input array
     
* is nearly sorted, the implementation requires approximately n
     
* comparisons.
  
Temporary storage requirements vary from a small constant
     
* for nearly sorted input arrays to n/2 object references for randomly
     
* ordered input arrays.
     
*
     
* <p>The implementation takes equal advantage of ascending and
     
* descending order in its input array, and can take advantage of
     
* ascending and descending order in different parts of the same
     
* input array.
  
It is well-suited to merging two or more sorted arrays:
     
* simply concatenate the arrays and sort the resulting array.
     
*
     
* <p>The implementation was adapted from Tim Peters's list sort for Python
     
* (<a href=" http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
     
* TimSort</a>).
  
It uses techniques from Peter McIlroy's "Optimistic
     
* Sorting and Information Theoretic Complexity", in Proceedings of the
     
* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
     
* January 1993.
     
*
     
* @param c the {@code Comparator} used to compare list elements.
     
*
          
A {@code null} value indicates that the elements'
     
*
          
{@linkplain Comparable natural ordering} should be used
     
* @throws ClassCastException if the list contains elements that are not
     
*
         
<i>mutually comparable</i> using the specified comparator
     
* @throws UnsupportedOperationException if the list's list-iterator does
     
*
         
not support the {@code set} operation
     
* @throws IllegalArgumentException
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>)
     
*
         
if the comparator is found to violate the {@link Comparator}
     
*
         
contract
     
* @since 1.8
     
*/

    
@SuppressWarnings({"unchecked", "rawtypes"})
    
default void sort(Comparator<? super E> c) {
        
Object[] a = this.toArray();
        
Arrays.sort(a, (Comparator) c);
        
ListIterator<E> i = this.listIterator();
        
for (Object e : a) {
            
i.next();
            
i.set((E) e);
        
}
    
}

    
/**
     
* Removes all of the elements from this list (optional operation).
     
* The list will be empty after this call returns.
     
*
     
* @throws UnsupportedOperationException if the <tt>clear</tt> operation
     
*
         
is not supported by this list
     
*/

    
void clear();


    
// Comparison and hashing

    
/**
     
* Compares the specified object with this list for equality.
  
Returns
     
* <tt>true</tt> if and only if the specified object is also a list, both
     
* lists have the same size, and all corresponding pairs of elements in
     
* the two lists are <i>equal</i>.
  
(Two elements <tt>e1</tt> and
     
* <tt>e2</tt> are <i>equal</i> if <tt>(e1==null ? e2==null :
     
* e1.equals(e2))</tt>.)
  
In other words, two lists are defined to be
     
* equal if they contain the same elements in the same order.
  
This
     
* definition ensures that the equals method works properly across
     
* different implementations of the <tt>List</tt> interface.
     
*
     
* @param o the object to be compared for equality with this list
     
* @return <tt>true</tt> if the specified object is equal to this list
     
*/

    
boolean equals(Object o);

    
/**
     
* Returns the hash code value for this list.
  
The hash code of a list
     
* is defined to be the result of the following calculation:
     
* <pre>{@code
     
*int hashCode = 1;
     
*for (E e : list)
     
*
         
hashCode = 31*hashCode + (e==null ? 0 : e.hashCode());
     
* }</pre>
     
* This ensures that <tt>list1.equals(list2)</tt> implies that
     
* <tt>list1.hashCode()==list2.hashCode()</tt> for any two lists,
     
* <tt>list1</tt> and <tt>list2</tt>, as required by the general
     
* contract of {@link Object#hashCode}.
     
*
     
* @return the hash code value for this list
     
* @see Object#equals(Object)
     
* @see #equals(Object)
     
*/

    
int hashCode();


    
// Positional Access Operations

    
/**
     
* Returns the element at the specified position in this list.
     
*
     
* @param index index of the element to return
     
* @return the element at the specified position in this list
     
* @throws IndexOutOfBoundsException if the index is out of range
     
*
         
(<tt>index &lt; 0 || index &gt;= size()</tt>)
     
*/

    
E get(int index);

    
/**
     
* Replaces the element at the specified position in this list with the
     
* specified element (optional operation).
     
*
     
* @param index index of the element to replace
     
* @param element element to be stored at the specified position
     
* @return the element previously at the specified position
     
* @throws UnsupportedOperationException if the <tt>set</tt> operation
     
*
         
is not supported by this list
     
* @throws ClassCastException if the class of the specified element
     
*
         
prevents it from being added to this list
     
* @throws NullPointerException if the specified element is null and
     
*
         
this list does not permit null elements
     
* @throws IllegalArgumentException if some property of the specified
     
*
         
element prevents it from being added to this list
     
* @throws IndexOutOfBoundsException if the index is out of range
     
*
         
(<tt>index &lt; 0 || index &gt;= size()</tt>)
     
*/

    
E set(int index, E element);

    
/**
     
* Inserts the specified element at the specified position in this list
     
* (optional operation).
  
Shifts the element currently at that position
     
* (if any) and any subsequent elements to the right (adds one to their
     
* indices).
     
*
     
* @param index index at which the specified element is to be inserted
     
* @param element element to be inserted
     
* @throws UnsupportedOperationException if the <tt>add</tt> operation
     
*
         
is not supported by this list
     
* @throws ClassCastException if the class of the specified element
     
*
         
prevents it from being added to this list
     
* @throws NullPointerException if the specified element is null and
     
*
         
this list does not permit null elements
     
* @throws IllegalArgumentException if some property of the specified
     
*
         
element prevents it from being added to this list
     
* @throws IndexOutOfBoundsException if the index is out of range
     
*
         
(<tt>index &lt; 0 || index &gt; size()</tt>)
     
*/

    
void add(int index, E element);

    
/**
     
* Removes the element at the specified position in this list (optional
     
* operation).
  
Shifts any subsequent elements to the left (subtracts one
     
* from their indices).
  
Returns the element that was removed from the
     
* list.
     
*
     
* @param index the index of the element to be removed
     
* @return the element previously at the specified position
     
* @throws UnsupportedOperationException if the <tt>remove</tt> operation
     
*
         
is not supported by this list
     
* @throws IndexOutOfBoundsException if the index is out of range
     
*
         
(<tt>index &lt; 0 || index &gt;= size()</tt>)
     
*/

    
E remove(int index);


    
// Search Operations

    
/**
     
* Returns the index of the first occurrence of the specified element
     
* in this list, or -1 if this list does not contain the element.
     
* More formally, returns the lowest index <tt>i</tt> such that
     
* <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
     
* or -1 if there is no such index.
     
*
     
* @param o element to search for
     
* @return the index of the first occurrence of the specified element in
     
*
         
this list, or -1 if this list does not contain the element
     
* @throws ClassCastException if the type of the specified element
     
*
         
is incompatible with this list
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws NullPointerException if the specified element is null and this
     
*
         
list does not permit null elements
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>)
     
*/

    
int indexOf(Object o);

    
/**
     
* Returns the index of the last occurrence of the specified element
     
* in this list, or -1 if this list does not contain the element.
     
* More formally, returns the highest index <tt>i</tt> such that
     
* <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
     
* or -1 if there is no such index.
     
*
     
* @param o element to search for
     
* @return the index of the last occurrence of the specified element in
     
*
         
this list, or -1 if this list does not contain the element
     
* @throws ClassCastException if the type of the specified element
     
*
         
is incompatible with this list
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>)
     
* @throws NullPointerException if the specified element is null and this
     
*
         
list does not permit null elements
     
*
         
(<a href="Collection.html#optional-restrictions">optional</a>)
     
*/

    
int lastIndexOf(Object o);


    
// List Iterators

    
/**
     
* Returns a list iterator over the elements in this list (in proper
     
* sequence).
     
*
     
* @return a list iterator over the elements in this list (in proper
     
*
         
sequence)
     
*/

    
ListIterator<E> listIterator();

    
/**
     
* Returns a list iterator over the elements in this list (in proper
     
* sequence), starting at the specified position in the list.
     
* The specified index indicates the first element that would be
     
* returned by an initial call to {@link ListIterator#next next}.
     
* An initial call to {@link ListIterator#previous previous} would
     
* return the element with the specified index minus one.
     
*
     
* @param index index of the first element to be returned from the
     
*
        
list iterator (by a call to {@link ListIterator#next next})
     
* @return a list iterator over the elements in this list (in proper
     
*
         
sequence), starting at the specified position in the list
     
* @throws IndexOutOfBoundsException if the index is out of range
     
*
         
({@code index < 0 || index > size()})
     
*/

    
ListIterator<E> listIterator(int index);

    
// View

    
/**
     
* Returns a view of the portion of this list between the specified
     
* <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive.
  
(If
     
* <tt>fromIndex</tt> and <tt>toIndex</tt> are equal, the returned list is
     
* empty.)
  
The returned list is backed by this list, so non-structural
     
* changes in the returned list are reflected in this list, and vice-versa.
     
* The returned list supports all of the optional list operations supported
     
* by this list.<p>
     
*
     
* This method eliminates the need for explicit range operations (of
     
* the sort that commonly exist for arrays).
  
Any operation that expects
     
* a list can be used as a range operation by passing a subList view
     
* instead of a whole list.
  
For example, the following idiom
     
* removes a range of elements from a list:
     
* <pre>{@code
     
*
      
list.subList(from, to).clear();
     
* }</pre>
     
* Similar idioms may be constructed for <tt>indexOf</tt> and
     
* <tt>lastIndexOf</tt>, and all of the algorithms in the
     
* <tt>Collections</tt> class can be applied to a subList.<p>
     
*
     
* The semantics of the list returned by this method become undefined if
     
* the backing list (i.e., this list) is <i>structurally modified</i> in
     
* any way other than via the returned list.
  
(Structural modifications are
     
* those that change the size of this list, or otherwise perturb it in such
     
* a fashion that iterations in progress may yield incorrect results.)
     
*
     
* @param fromIndex low endpoint (inclusive) of the subList
     
* @param toIndex high endpoint (exclusive) of the subList
     
* @return a view of the specified range within this list
     
* @throws IndexOutOfBoundsException for an illegal endpoint index value
     
*
         
(<tt>fromIndex &lt; 0 || toIndex &gt; size ||
     
*
         
fromIndex &gt; toIndex</tt>)
     
*/

    
List<E> subList(int fromIndex, int toIndex);

    
/**
     
* Creates a {@link Spliterator} over the elements in this list.
     
*
     
* <p>The {@code Spliterator} reports {@link Spliterator#SIZED} and
     
* {@link Spliterator#ORDERED}.
  
Implementations should document the
     
* reporting of additional characteristic values.
     
*
     
* @implSpec
     
* The default implementation creates a
     
* <em><a href="Spliterator.html#binding">late-binding</a></em> spliterator
     
* from the list's {@code Iterator}.
  
The spliterator inherits the
     
* <em>fail-fast</em> properties of the list's iterator.
     
*
     
* @implNote
     
* The created {@code Spliterator} additionally reports
     
* {@link Spliterator#SUBSIZED}.
     
*
     
* @return a {@code Spliterator} over the elements in this list
     
* @since 1.8
     
*/

    
@Override
    
default Spliterator<E> spliterator() {
        
return Spliterators.spliterator(this, Spliterator.ORDERED);
    
}
}