infixToBinaryCreateSubtree

infixToBinaryCreateSubtree

var createSubtree = function createSubtree(operator, tree) {
	if (tree == null) {
		var right = outputStack.pop(),
			left = outputStack.pop();
		tree = new BinaryTreeNode(operator);
		tree.right = right instanceof BinaryTreeNode ? right : new BinaryTreeNode(right);
		tree.left = left instanceof BinaryTreeNode ? left : new BinaryTreeNode(left);
	} else {
		var subtree = tree,
			left = outputStack.pop();
		tree = new BinaryTreeNode(operator);
		tree.right = subtree;
		tree.left = left instanceof BinaryTreeNode ? left : new BinaryTreeNode(left);
	}

	if (!operatorStack.isEmpty() && operator.lessOrEqualInPrecedenceTo(operatorStack.peek())) {
		return createSubtree(operatorStack.pop(), tree);
	} else {
		return tree;
	}
}