org.apache.xml.utils
Class BoolStack

java.lang.Object
  org.apache.xml.utils.BoolStack

All Implemented Interfaces:

Cloneable

public final class BoolStack

extends Object

implements Cloneable

Simple stack for boolean values.

Field Summary

private int	m_allocatedSize Array size allocated
private int	m_index Index into the array of booleans
private boolean[]	m_values Array of boolean values

Constructor Summary

BoolStack()
Default constructor.

BoolStack(int size)
Construct a IntVector, using the given block size.

Method Summary

Object	clone() Creates and returns a copy of this object.
private void	grow() Grows the size of the stack
boolean	isEmpty() Tests if this stack is empty.
boolean	peek() Looks at the object at the top of this stack without removing it from the stack.
boolean	peekOrFalse() Looks at the object at the top of this stack without removing it from the stack.
boolean	peekOrTrue() Looks at the object at the top of this stack without removing it from the stack.
boolean	pop() Removes the object at the top of this stack and returns that object as the value of this function.
boolean	popAndTop() Removes the object at the top of this stack and returns the next object at the top as the value of this function.
boolean	push(boolean val) Pushes an item onto the top of this stack.
void	setTop(boolean b) Set the item at the top of this stack
int	size() Get the length of the list.

Methods inherited from class java.lang.Object

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

Field Detail

m_values

private boolean[] m_values

Array of boolean values

m_allocatedSize

private int m_allocatedSize

Array size allocated

m_index

private int m_index

Index into the array of booleans

Constructor Detail

BoolStack

public BoolStack()

Default constructor. Note that the default block size is very small, for small lists.

BoolStack

public BoolStack(int size)

Construct a IntVector, using the given block size.

Parameters:

size - array size to allocate

Method Detail

size

public final int size()

Get the length of the list.

Returns:

Current length of the list

push

public final boolean push(boolean val)

Pushes an item onto the top of this stack.

Parameters:

val - the boolean to be pushed onto this stack.

Returns:

the item argument.

pop

public final boolean pop()

Removes the object at the top of this stack and returns that object as the value of this function.

Returns:

The object at the top of this stack.

Throws:

EmptyStackException - if this stack is empty.

popAndTop

public final boolean popAndTop()

Removes the object at the top of this stack and returns the next object at the top as the value of this function.

Returns:

Next object to the top or false if none there

setTop

public final void setTop(boolean b)

Set the item at the top of this stack

Parameters:

b - Object to set at the top of this stack

peek

public final boolean peek()

Looks at the object at the top of this stack without removing it from the stack.

Returns:

the object at the top of this stack.

Throws:

EmptyStackException - if this stack is empty.

peekOrFalse

public final boolean peekOrFalse()

Looks at the object at the top of this stack without removing it from the stack. If the stack is empty, it returns false.

Returns:

the object at the top of this stack.

peekOrTrue

public final boolean peekOrTrue()

Looks at the object at the top of this stack without removing it from the stack. If the stack is empty, it returns true.

Returns:

the object at the top of this stack.

isEmpty

public boolean isEmpty()

Tests if this stack is empty.

Returns:

true if this stack is empty; false otherwise.

grow

private void grow()

Grows the size of the stack

clone

public Object clone()
             throws CloneNotSupportedException

Description copied from class: Object

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

 x.clone() != x

will be true, and that the expression:

 x.clone().getClass() == x.getClass()

will be true, but these are not absolute requirements. While it is typically the case that:

 x.clone().equals(x)

will be true, this is not an absolute requirement.

By convention, the returned object should be obtained by calling super.clone. If a class and all of its superclasses (except Object) obey this convention, it will be the case that x.clone().getClass() == x.getClass().

By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by super.clone before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by super.clone need to be modified.

The method clone for class Object performs a specific cloning operation. First, if the class of this object does not implement the interface Cloneable, then a CloneNotSupportedException is thrown. Note that all arrays are considered to implement the interface Cloneable. Otherwise, this method creates a new instance of the class of this object and initializes all its fields with exactly the contents of the corresponding fields of this object, as if by assignment; the contents of the fields are not themselves cloned. Thus, this method performs a "shallow copy" of this object, not a "deep copy" operation.

The class Object does not itself implement the interface Cloneable, so calling the clone method on an object whose class is Object will result in throwing an exception at run time.

Overrides:

clone in class Object

Returns:

a clone of this instance.

Throws:

CloneNotSupportedException - if the object's class does not support the Cloneable interface. Subclasses that override the clone method can also throw this exception to indicate that an instance cannot be cloned.

See Also:

Cloneable