unaryExpression method

@override Parser unaryExpression()

Implementation

@override
Parser unaryExpression() => super.unaryExpression().map((c) {
      if (c is List && c.length == 2) {
        if (c[0].value == '-') {
          if (c[1] is Expression<Number>) {
            return NegateNumberExpression(c[1]);
          }
          if (c[1] is Expression<Duration>) {
            return NegateDurationExpression(c[1]);
          }
        } else if (c[0].value == '!') {
          if (c[1] is Expression<bool>) {
            return NegateBoolExpression(c[1]);
          }
        }
      }
      return c;
    });