package trees.expressiontrees;

import java.util.EmptyStackException;
import java.util.Stack;
import java.util.Vector;

public class ExpressionTree {
	
	private ExpressionNode root;
	
	/* This method builds an expression tree from 
	 * the inverse polish notation of the expression.
	 */
	public void buildTree(Vector<Token> v)throws Exception {
		throw new UnsupportedOperationException();
	}
	
	/* Method uses recursion to evaluate an expression
	 * given its expression tree.
	 */
	public double evaluate() {
		return root.value();
	}
	
	public double eval() {
		double result = 0;
		try {
			result = postOrderEvaluation(root);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return result;
	}
	
	/* Method uses post order traversal of the expression tree
	 * to evaluate the expression value.
	 */
	private double postOrderEvaluation(ExpressionNode node) throws Exception{
		throw new UnsupportedOperationException();
	}
}