byucc.jhdl.base.list
Class TreeList

java.lang.Object
  byucc.jhdl.base.list.TreeList

All Implemented Interfaces:

List

Direct Known Subclasses:

NodeList

public class TreeList

extends java.lang.Object

implements List

This list structure is based on a modified binary tree design. Each object keeps track of its next sibling and its first child. This is useful for objects that are guaranteed to appear only once, on a single list. Insert, init, atEnd, next are all O(1), append and prev are not presently supported, and elementCount is O(n). To make a treelist of objects, the target class must implement TreeListable.

Author:

Eric Blake

Constructor Summary

TreeList()

Method Summary

protected void	append(TreeListable obj) Append not supported at present.
boolean	atEnd() Returns true when the current pointer is at the end of the list.
boolean	delete(TreeListable obj) If found, deletes the child from the list of children, then reinitializes list
int	elementCount() Returns the size of the list; i.e.
java.util.Enumeration	elements() Returns an enumeration for safe simultaneous traversal of this list
boolean	empty() Returns true if the list has no elements
protected TreeListable	getElt() Returns the object pointed to by the current pointer.
void	init() Initializes the list to start at the first child, for traversal.
boolean	inList(java.lang.Object obj) Returns true if the object is found in the list
boolean	inList(TreeListable obj) Returns true if the object is found in the list
protected void	insert(TreeListable obj) Inserts a child to the list
void	next() Advances the current pointer, for iterating through the list.
void	prev() Prev not supported at present.
java.lang.String	toString() For nice output; useful in debugging.

Methods inherited from class java.lang.Object

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

Constructor Detail

TreeList

public TreeList()

Method Detail

insert

protected void insert(TreeListable obj)

Inserts a child to the list

Parameters:

obj - the child to insert

delete

public boolean delete(TreeListable obj)

If found, deletes the child from the list of children, then reinitializes list

Parameters:

obj - the child to delete

Returns:

true if the element was found and deleted

empty

public final boolean empty()

Returns true if the list has no elements

Returns:

true if empty

init

public final void init()

Initializes the list to start at the first child, for traversal.

Specified by:

init in interface List

Returns:

an Iterator for simultaneous traversal

atEnd

public final boolean atEnd()

Returns true when the current pointer is at the end of the list.

Specified by:

atEnd in interface List

Returns:

true if at the end of the list

next

public final void next()

Advances the current pointer, for iterating through the list.

Specified by:

next in interface List

prev

public final void prev()

Prev not supported at present.

Specified by:

prev in interface List

getElt

protected TreeListable getElt()

Returns the object pointed to by the current pointer.

Returns:

the current node.

elementCount

public final int elementCount()

Returns the size of the list; i.e. the number of children belonging to a node

Specified by:

elementCount in interface List

Returns:

number of elements in list

append

protected void append(TreeListable obj)

Append not supported at present.

inList

public final boolean inList(java.lang.Object obj)

Returns true if the object is found in the list

Specified by:

inList in interface List

Returns:

true if the object is in the list

inList

public final boolean inList(TreeListable obj)

Returns true if the object is found in the list

Returns:

true if the object is in the list

toString

public java.lang.String toString()

For nice output; useful in debugging.

Returns:

a String representing this list

elements

public java.util.Enumeration elements()

Returns an enumeration for safe simultaneous traversal of this list

Returns:

an enumerator for this list