scranton.stack
Class StackViaLinear1Ind

java.lang.Object
  scranton.Linear1
      scranton.Linear1Ind
          scranton.stack.StackViaLinear1Ind

All Implemented Interfaces:

Stack

public class StackViaLinear1Ind

extends Linear1Ind

implements Stack

An implementation of the Stack interface via extension of the Linear1Ind class. Invariant: The class warranty is voided is a client directly applies any Linear1Ind class method.

Field Summary

Fields inherited from class scranton.Linear1

data, link

Constructor Summary

	StackViaLinear1Ind() Constructs an empty stack by extending the Linear1Indclass.
protected	StackViaLinear1Ind(java.lang.Object obj) This constructor is for use by extensions of this class.

Method Summary

Linear1	factory() Returns a null Linear1() object
boolean	isEmpty() Stack does not change, returns true iff the stack is empty.
java.lang.Object	pop() Decrease the size of the stack by one by removing and returning the object at the top.
void	push(java.lang.Object item) Increase the size of the stack by one by placing item as the new top of the stack.
java.lang.Object	topOf() Stack does not change, returns the reference to the top object in the stack.
java.lang.String	toString() Returns a string representation of the stack.

Methods inherited from class scranton.Linear1Ind

indInsert, indRemove, indReplace, indView

Methods inherited from class scranton.Linear1

getData, getLink, setData, setLink

Methods inherited from class java.lang.Object

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

Constructor Detail

StackViaLinear1Ind

public StackViaLinear1Ind()

Constructs an empty stack by extending the Linear1Indclass.

StackViaLinear1Ind

protected StackViaLinear1Ind(java.lang.Object obj)

This constructor is for use by extensions of this class. Constructs a stack with the indicated object.

Method Detail

isEmpty

public boolean isEmpty()

Description copied from interface: Stack

Stack does not change, returns true iff the stack is empty.

Specifications:

S'=S
Return S==()

Specified by:

isEmpty in interface Stack

Returns:

boolean this==().

topOf

public java.lang.Object topOf()

Description copied from interface: Stack

Stack does not change, returns the reference to the top object in the stack.

Specifications:

S!=()S'=S
Return a_n-1

Specified by:

topOf in interface Stack

Returns:

Object Top of stack.

push

public void push(java.lang.Object item)

Description copied from interface: Stack

Increase the size of the stack by one by placing item as the new top of the stack.

Specifications:

S'=(S, obj)

Specified by:

push in interface Stack

Parameters:

item - The new top of stack

pop

public java.lang.Object pop()

Description copied from interface: Stack

Decrease the size of the stack by one by removing and returning the object at the top. Note: that the stack cannot be empty.

Specifications:

S!=()S = (S', a_n-1)
Return: a_n-1

Specified by:

pop in interface Stack

Returns:

Object Top of stack.

factory

public Linear1 factory()

Description copied from class: Linear1

Returns a null Linear1() object

Overrides:

factory in class Linear1

Returns:

A null Linear1() object

toString

public java.lang.String toString()

Description copied from interface: Stack

Returns a string representation of the stack. The format is, "TOP[O_top\t...\tO_bottom]BOTTOM"

Specified by:

toString in interface Stack

Overrides:

toString in class Linear1Ind

Returns:

String Returns a tab delimited string of the objects in the recursive Linear1 structure.