public function data_exceptions() {
    return array(
      array(
        'n # 2',              // Invalid expression to parse.
        'Unknown symbol "#"', // Expected exception message.
        false,                // Whether to call the get() method or not.
      ),
      array(
        'n & 1',
        'Unknown operator "&"',
        false,
      ),
      array(
        '((n)',
        'Mismatched parentheses',
        false,
      ),
      array(
        '(n))',
        'Mismatched parentheses',
        false,
      ),
      array(
        'n : 2',
        'Missing starting "?" ternary operator',
        false,
      ),
      array(
        'n ? 1',
        'Unknown operator "?"',
        true,
      ),
      array(
        'n n',
        'Too many values remaining on the stack',
        true,
      ),
    );
  }