Interface Loop<E>

All Superinterfaces:

java.lang.Iterable<E>

public interface Loop<E>
extends java.lang.Iterable<E>

A Loop ADT is a circular sequence of items. A Loop has a current item and the ability to move forward or backwards. A Loop can be modified by removing the current item or by adding an item before the current item.

Method Summary

Methods

Modifier and Type	Method and Description
void	backward() Moves the current item backward one item resulting in the item that is immediately before the current item becoming the current item.
void	forward() Advances the current item forward one item resulting in the item that is immediately after the current item becoming the current item.
E	getCurrent() Returns the current item.
void	insert(E item) Adds the given item immediately before the current item.
boolean	isEmpty() Returns true if this Loop is empty and false otherwise.
java.util.Iterator<E>	iterator() Returns an iterator for this Loop.
E	removeCurrent() Removes and returns the current item.
int	size() Returns the number of items in this Loop.

Method Detail

getCurrent

E getCurrent()

Returns the current item. If the Loop is empty, an EmptyLoopException is thrown.

Returns:

the current item

Throws:

EmptyLoopException - if the Loop is empty

insert

void insert(E item)

Adds the given item immediately before the current item. After the new item has been added, the new item becomes the current item.

Parameters:

item - the item to add

removeCurrent

E removeCurrent()

Removes and returns the current item. The item immediately after the removed item then becomes the current item. If the Loop is empty initially, an EmptyLoopException is thrown.

Returns:

the removed item

Throws:

EmptyLoopException - if the Loop is empty

forward

void forward()

Advances the current item forward one item resulting in the item that is immediately after the current item becoming the current item. If the Loop is empty initially, an EmptyLoopException is thrown.

Throws:

EmptyLoopException - if the Loop is empty

backward

void backward()

Moves the current item backward one item resulting in the item that is immediately before the current item becoming the current item. If the Loop is empty initially, an EmptyLoopException is thrown.

Throws:

EmptyLoopException - if the Loop is empty

size

int size()

Returns the number of items in this Loop.

Returns:

the number of items in this Loop

isEmpty

boolean isEmpty()

Returns true if this Loop is empty and false otherwise.

Returns:

true if this Loop is empty; false otherwise.

iterator

java.util.Iterator<E> iterator()

Returns an iterator for this Loop.

Specified by:

iterator in interface java.lang.Iterable<E>

Returns:

an iterator for this Loop