The package contains an immutable value object called PositiveNum that encapsulates a positive number (any number greater than 0) which can be int or double. PositiveNum guarantees that its value is always positive and can't be change after creation. PositiveNum can't be created with 0 or negative value.

Getting started

How to start using the package

dart pub add positive_num

Or specify the package's git url in pubspec.yaml at the dependencies section like that

dependencies:
  positive_num:
    git:
      url: https://github.com/maxeema/positive_num.git

Then import it in your code.

import 'package:positive_num/positive_num.dart';

Usage

import 'package:positive_num/positive_num.dart';

void main() {
  var someNumber = 1;
  //
  final (:error, :instance) = PositiveNum.create(someNumber);
  if (instance != null) {
    final positiveNum = instance;
    print('Created a PositiveNum instance with value $positiveNum.');
  } else {
    print('Error. $error');
  }
}

Before run

dart pub get

Run example

dart run example/positive_num_example.dart

Run tests

dart test

Copyright

© Max Shemetov, 2023