Token currLowestPrecedenceToken = null;
int currLowestPrecedencTokenIndex = -1; // index of any operator in curr
// string
int currLowestPrecedence = 10; // higher than any other
int parDepth = 0; // parenthesis depth
TokenIterator tokIt = tokens.iterator();
while (tokIt.hasNext()) {
Token tok = tokIt.next();
// keep track of parentheses,
if (tok.getString().equals("(")) {
parDepth++;
} else if (tok.getString().equals(")")) {
parDepth--;