Heterogeneous Container					BS_Tree class

NAME
	BS_Tree - store data in a binary search tree

FILES
	BS_Tree.java
	BST_Iterator.java
	BST_Node.java
	Comparison.java

SYNOPSIS
	class BS_Tree;

DESCRIPTION
	The BS_Tree container stores Object values in a binary search
	tree. The user can insert and delete values from the BS_Tree
	using the methods insert() and remove(). The container also
	offers iterators for access only and methods for finding a
	value in the container. The user of a BS_Tree needs to specify 
	an object that is a subtype of Comparison and that can be used 
	to compare two Objects stored in the BS_Tree.
	
METHODS
	Special methods:
		public BS_Tree(Comparison cmp);
			default constructor; takes as parameter
			an object that knows how to compare
			two Objects.

		BST_Node next(BST_Node current);
			this is a class method used by BST_Iterator
			to find the next node that follows after
			current.

	Methods:
		public int size();
			returns the size of the BS_Tree;

		public boolean empty();
			returns true if size is 0;

		public void insert(Object value);
			inserts a new value in the BS_Tree. 
			Duplicates are allowed.

		public boolean remove(Object value);
			removes a value from the tree. Returns
			true if value was found and removed,
			false if the value wasn't found.

		public BST_Iterator find(Object value);
			returns an iterator to the first element 
			with the given value found in the
			BS_Tree. Returns an iterator for which
			atEnd() returns true if such element is 
			not found.

		public BST_Iterator iterator();
			returns an iterator to the first value 
			in the BS_Tree. The iterator allows 
			the user to move inorder over the 
			values in the tree.

	Comments:
		Comparison is an abstract class that must be
		extended by the user in order to provide 
		an adequate comparison operation between two
		Objects stored in the BS_Tree. It offers the
		following method:

			public int compare(Object val1, 
					   Object val2);
				this method is expected to
				compare val1 and val2 and return:
				- a negative value if val1 < val2
				- a positive value if val1 > val2
				- 0 if val1 == val2
		
		BST_Iterator is a class that defines the 
		following methods:

			public boolean atEnd();
				returns true if iterator went
				past the last element of the
				container.

			public void next();
				move the iterator to the next
				element in the container.

			public Object current();
				returns the current element
				pointed by the iterator.

EXAMPLES:
	See the files BS_Tree_int.java, BST_int_Iterator.java,
	Comparison_Integer.java, BS_Tree_String.java, 
	BST_String_Iterator.java and Comparison_String.java for 
	examples of how to create homogeneous BS_Tree's for 
	holding	integers and Strings.

	The files BST_int_Test.java, BST_String_Test.java contain
	examples of use for the homogeneous containers defined
	in BS_Tree_int.java and BS_Tree_String.java.

BUGS
	No known bugs at this time.

Laurentiu Cristofor			Last Change: November 6th, 1998