code: static boolean isUnaryOperatorType(Token type) {
      switch (type) {
        case DELPROP:
        case VOID:
        case TYPEOF:
        case POS:
        case NEG:
        case BITNOT:
        case NOT:
          return true;
  
        default:
          return false;
      }
    }
docs: An operator taking only one operand.
  These all parse very similarly, taking LeftHandSideExpression operands.