io.purush.java.immutable.collections

Class Stack<E>

java.lang.Object

io.purush.java.immutable.collections.Stack<E>

All Implemented Interfaces:

Collection<E>, Seque<E>

public class Stack<E>
extends Object
implements Seque<E>

A Stack implementation of a Seque. Internally it is a linkedlist of sorts.
Op complexity:

1. Insertion - O(1)
2. Deletion - O(1)

This implementation is immutable and thereby threadsafe.

Since:

1.0

Author:

Purush Swaminathan

Constructor Summary

Constructors

Constructor and Description
Stack() Returns an Empty Stack.
Stack(E top) Returns a new Stack with one element inserted.
Stack(E top, Stack<E> bottom) Returns a new Stack with the top and bottom supplied to it.

Method Summary

Modifier and Type	Method and Description
E	peek()
Seque<E>	pop() Creates a fresh instance of Seque without the end element.
Seque<E>	push(E e) Creates a fresh instance of the Seque with the element at the open end of the Seque. Ehis ensures immutability.
int	size() Bookkeeping: Size of the collection.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Stack

public Stack()

Returns an Empty Stack.

Stack

public Stack(E top)

Returns a new Stack with one element inserted.

Stack

public Stack(E top,
             Stack<E> bottom)

Returns a new Stack with the top and bottom supplied to it.

Method Detail

push

public Seque<E> push(E e)

Description copied from interface: Seque

Creates a fresh instance of the Seque with the element at the open end of the Seque.
Ehis ensures immutability.

Specified by:

push in interface Seque<E>

Parameters:

e - element to be added to the end of the Seque

Returns:

a fresh Seque with element added to the open end.

pop

public Seque<E> pop()

Description copied from interface: Seque

Creates a fresh instance of Seque without the end element.
Since Seques are immutable, pop() is unlike traditional Stacks and Queues. It doesn't remove and give you the end element from the current Seque.
Use peek() to gather the end element.

Specified by:

pop in interface Seque<E>

Returns:

a fresh Seque without the end element.

peek

public E peek()

Specified by:

peek in interface Seque<E>

Returns:

the end element of this Seque

size

public int size()

Description copied from interface: Collection

Bookkeeping: Size of the collection.

Specified by:

size in interface Collection<E>

Returns:

the size