dtypes
Class PSStack

java.lang.Object
  dtypes.PSStack

Direct Known Subclasses:

PSPath

public class PSStack

extends java.lang.Object

The Stack ADT definition. Every newly created object has specific bevarious declared. This ADT offers all the functions needed to create and operate PSStack.

Constructor Summary

PSStack()
Creates a new PSStack.

Method Summary

int	getSize() Returns the size of the stack.
boolean	isEmpty() Removes all elements from stack.
java.lang.Class	peek(int n) Retrieves the type of peek Precondition : Postcondition : The size of the stack is returned.
java.lang.Object	pop() Returns the size of the stack.
void	push(java.lang.Object element) Pushes an element on top of the stack.

Methods inherited from class java.lang.Object

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

Constructor Detail

PSStack

public PSStack()

Creates a new PSStack.
Precondition : There must be enough memory in the heap.
Postcondition : A new stack will be created.

Method Detail

push

public void push(java.lang.Object element)

Pushes an element on top of the stack.
Precondition : There is enough memory in the heap.
Postcondition : The element is pushed into the stack.

Parameters:

element - The element to be pushed.

isEmpty

public boolean isEmpty()

Removes all elements from stack.
Precondition : A valid instance of PSStack must be created.
Postcondition : Everything is erased. public void clear() { v.clear(); return; } /////////////////// ACCESSOR ////////////////////// // boolean_isEmpty // Observer /** Checks whether the stack is empty.
Precondition : A valid instance of PSStack must be created.
Postcondition : A response to whether the stack is empty.

Returns:

True if the stack is empty, false otherwise.

getSize

public int getSize()

Returns the size of the stack.
Precondition : A valid instance of PSStack must be created.
Postcondition : The size of the stack is returned.

Returns:

The size of the stack.

pop

public java.lang.Object pop()

Returns the size of the stack.
Precondition : A valid instance of PSStack must be created.
Postcondition : The element is returned.

Returns:

The element on top of the stack.

peek

public java.lang.Class peek(int n)

Retrieves the type of peek
Precondition :
Postcondition : The size of the stack is returned.

Returns:

The type of an object