structure
Interface List

All Superinterfaces:
Structure
All Known Implementing Classes:
AbstractList

public interface List
extends Structure

Interface describing lists. Lists are collections of data with a head and tail. Values may be added or removed from either end, as well as by value from the middle. The structure package provides several implementations of the List interface, each of which has its particular strengths and weaknesses.

Example usage:

To place a copy of every unique parameter passed to a program into a List, we could use the following:

 public static void main(String[] arguments)
 {
     List argList = new SinglyLinkedList();
     for (int i = 0; i < arguments.length; i++){
	   if (!argList.contains(arguments[i])){
	       argList.add(arguments[i]);
         }
    }
    System.out.println(argList);
 }
 

See Also:
SinglyLinkedList, DoublyLinkedList, CircularList

Method Summary
 void add(int i, java.lang.Object o)
          Insert value at location.
 void add(java.lang.Object value)
          Add an object to tail of list.
 void addFirst(java.lang.Object value)
          Add a value to the head of the list.
 void addLast(java.lang.Object value)
          Add a value to tail of list.
 void clear()
          Remove all elements of list.
 boolean contains(java.lang.Object value)
          Check to see if a value is in list.
 java.lang.Object get()
          Retrieves value from tail of list.
 java.lang.Object get(int i)
          Get value at location i.
 java.lang.Object getFirst()
          Fetch first element of list.
 java.lang.Object getLast()
          Fetch last element of list.
 int indexOf(java.lang.Object value)
          Determine first location of a value in list.
 boolean isEmpty()
          Determine if list is empty.
 java.util.Iterator iterator()
          Construct an iterator to traverse elements of list from head to tail, in order.
 int lastIndexOf(java.lang.Object value)
          Determine last location of a value in list.
 java.lang.Object remove()
          Removes value from tail of list.
 java.lang.Object remove(int i)
          Remove and return value at location i.
 java.lang.Object remove(java.lang.Object value)
          Remove a value from list.
 java.lang.Object removeFirst()
          Remove a value from first element of list.
 java.lang.Object removeLast()
          Remove last value from list.
 java.lang.Object set(int i, java.lang.Object o)
          Set value stored at location i to object o, returning old value.
 int size()
          Determine size of list.
 
Methods inherited from interface structure.Structure
elements, values
 

Method Detail

size

public int size()
Determine size of list.

Specified by:
size in interface Structure
Returns:
The number of elements in list.

isEmpty

public boolean isEmpty()
Determine if list is empty.

Specified by:
isEmpty in interface Structure
Returns:
True if list has no elements.

clear

public void clear()
Remove all elements of list.

Specified by:
clear in interface Structure

addFirst

public void addFirst(java.lang.Object value)
Add a value to the head of the list.

Parameters:
value - The value to be added to the head of the list.

addLast

public void addLast(java.lang.Object value)
Add a value to tail of list.

Parameters:
value - The value to be added to tail of list.

getFirst

public java.lang.Object getFirst()
Fetch first element of list.

Returns:
A reference to first element of list.

getLast

public java.lang.Object getLast()
Fetch last element of list.

Returns:
A reference to last element of list.

removeFirst

public java.lang.Object removeFirst()
Remove a value from first element of list.

Returns:
The value actually removed.

removeLast

public java.lang.Object removeLast()
Remove last value from list.

Returns:
The value actually removed.

remove

public java.lang.Object remove(java.lang.Object value)
Remove a value from list. At most one of value will be removed.

Specified by:
remove in interface Structure
Parameters:
value - The value to be removed.
Returns:
The actual value removed.

add

public void add(java.lang.Object value)
Add an object to tail of list.

Specified by:
add in interface Structure
Parameters:
value - The value to be added to tail of list.
See Also:
addLast(java.lang.Object)

remove

public java.lang.Object remove()
Removes value from tail of list.

Returns:
object removed.

get

public java.lang.Object get()
Retrieves value from tail of list.

Returns:
object found at end of list

contains

public boolean contains(java.lang.Object value)
Check to see if a value is in list.

Specified by:
contains in interface Structure
Parameters:
value - value sought.
Returns:
True if value is within list.

indexOf

public int indexOf(java.lang.Object value)
Determine first location of a value in list.

Parameters:
value - The value sought.
Returns:
index (0 is first element) of value, or -1

lastIndexOf

public int lastIndexOf(java.lang.Object value)
Determine last location of a value in list.

Parameters:
value - value sought.
Returns:
index (0 is first element) of value, or -1

get

public java.lang.Object get(int i)
Get value at location i.

Parameters:
i - position of value to be retrieved.
Returns:
value retrieved from location i (returns null if i invalid)

set

public java.lang.Object set(int i,
                            java.lang.Object o)
Set value stored at location i to object o, returning old value.

Parameters:
i - location of entry to be changed.
o - new value
Returns:
former value of ith entry of list.

add

public void add(int i,
                java.lang.Object o)
Insert value at location.

Parameters:
i - index of this new value
o - value to be stored

remove

public java.lang.Object remove(int i)
Remove and return value at location i.

Parameters:
i - position of value to be retrieved.
Returns:
value retrieved from location i (returns null if i invalid)

iterator

public java.util.Iterator iterator()
Construct an iterator to traverse elements of list from head to tail, in order.

Specified by:
iterator in interface Structure
Returns:
Iterator that traverses list.
See Also:
AbstractIterator, Iterator, Enumeration, Structure.elements()