package euler_tour.expressions;

import euler_tour.EulerTour;
import position.Position;
import tree.binarytree.BinaryTree;

/**
 * Created with MONSTER.
 * User: xgiovio
 * Date: 27/04/2014
 * Time: 13:11
 */
public class StringExpressionTour extends EulerTour<ExpressionTerm,String> {

    public String execute(BinaryTree<ExpressionTerm> T) {
        init(T);
        return eulerTour(T.root());
    }



    protected void visitLeft(Position<ExpressionTerm> v, TourResult<String> r) {
        if (tree.isInternal(v)) {
            r.out = new String("(");
        }else {
            r.out = new String("");
        }
    }

    protected void visitBelow(Position<ExpressionTerm> v, TourResult<String> r) {
        if (tree.isInternal(v)) {
            r.out += r.left;
        }
        r.out += v.element();
    }

    protected void visitRight(Position<ExpressionTerm> v,TourResult<String> r) {
        if (tree.isInternal(v)) {
            r.out += r.right;
            r.out += ")";
        }
    }


}