net.sf.saxon.tree.util

Class IndexedStack<T>

java.lang.Object

net.sf.saxon.tree.util.IndexedStack<T>

All Implemented Interfaces:

java.lang.Iterable<T>

public class IndexedStack<T>
extends java.lang.Object
implements java.lang.Iterable<T>

This class replicates functionality that is available in a Java Stack, but not in a C# Stack, for example the ability to access elements by direct index (0-based, counting from the bottom of the stack). It is used in place of Stack in the few places where this functionality is needed.

The stack is iterable, and iteration is in bottom-to-top order (like Java, but unlike a C# stack where iteration is top-to-bottom)

Constructor Summary

Constructors

Constructor and Description
IndexedStack() Create an empty stack with a default initial space allocation
IndexedStack(int size) Create an empty stack with a specified initial space allocation

Method Summary

Modifier and Type	Method and Description
boolean	contains(T value) Search for an item on the stack
T	get(int i) Get the item at position N in the stack, without changing the state of the stack
int	indexOf(T value) Search for an item on the stack, starting from the bottom
boolean	isEmpty() Ask if the stack is empty
java.util.Iterator<T>	iterator() Iterate the stack in bottom to top order
T	peek() Get the item on the top of the stack, without changing the state of the stack
T	pop() Get the item on the top of the stack, and remove it from the stack
void	push(T item) Add an item to the top of the stack
void	set(int i, T value) Overwrite the item at position N in the stack
int	size() Get the current height of the stack

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

IndexedStack

public IndexedStack()

Create an empty stack with a default initial space allocation

IndexedStack

public IndexedStack(int size)

Create an empty stack with a specified initial space allocation

Parameters:

size - the number of entries to be allocated

Method Detail

size

public int size()

Get the current height of the stack

Returns:

the number of items on the stack

isEmpty

public boolean isEmpty()

Ask if the stack is empty

Returns:

true if the stack contains no items

push

public void push(T item)

Add an item to the top of the stack

Parameters:

item - the item to be added

peek

public T peek()

Get the item on the top of the stack, without changing the state of the stack

Returns:

the topmost item

Throws:

java.util.EmptyStackException - if the stack is empty

pop

public T pop()

Get the item on the top of the stack, and remove it from the stack

Returns:

the topmost item

Throws:

java.util.EmptyStackException - if the stack is empty

get

public T get(int i)

Get the item at position N in the stack, without changing the state of the stack

Parameters:

i - the position of the required item, where the first item counting from the bottom of the stack is position 0 (zero)

Returns:

the item at the specified position

Throws:

java.lang.IndexOutOfBoundsException - if {code i} is negative, or greater than or equal to the stack size

set

public void set(int i,
                T value)

Overwrite the item at position N in the stack

Parameters:

i - the position of the required item, where the first item counting from the bottom of the stack is position 0 (zero)

value - the item to be put at the specified position

Throws:

java.lang.IndexOutOfBoundsException - if {code i} is negative, or greater than or equal to the stack size

contains

public boolean contains(T value)

Search for an item on the stack

Parameters:

value - the item being sought

Returns:

true if the stack contains an item equal to the sought item

indexOf

public int indexOf(T value)

Search for an item on the stack, starting from the bottom

Parameters:

value - the item being sought

Returns:

the index position of the first item found that is equal to value, or -1 if no such item is found

iterator

public java.util.Iterator<T> iterator()

Iterate the stack in bottom to top order

Specified by:

iterator in interface java.lang.Iterable<T>

Returns:

an iterator that starts at the bottom of the stack and proceeds to the top