function parseRelational(state) {
    var params = [parseShift(state)];
    var conditionals = [];
    var operators = {
      '==': 'equal',
      '!=': 'unequal',
      '<': 'smaller',
      '>': 'larger',
      '<=': 'smallerEq',
      '>=': 'largerEq'
    };

    while (operators.hasOwnProperty(state.token)) {
      // eslint-disable-line no-unmodified-loop-condition
      var cond = {
        name: state.token,
        fn: operators[state.token]
      };
      conditionals.push(cond);
      getTokenSkipNewline(state);
      params.push(parseShift(state));
    }

    if (params.length === 1) {
      return params[0];
    } else if (params.length === 2) {
      return new OperatorNode(conditionals[0].name, conditionals[0].fn, params);
    } else {
      return new RelationalNode(conditionals.map(function (c) {
        return c.fn;
      }), params);
    }
  }
Parse a chained conditional, like 'a > b >= c'
@return {Node} node