result_option 1.1.1

The types that represent the result of the operation. this is useful when designing API requires that an user should handle errors explicitly.

Installing

dependencies:
  result_option:

import 'package:result_option/result_option.dart';

Usage

• Result

  It represent the result of an operation.

  This is useful for API designs that require explicit error handling.

  • Basic

    final result = fetchCompanies(startsWithG: true);
        
    result.match(
      ok: (c) => print(c),
      err: (e) => print(e),
    );
    

  • Construct

    Result<int, String> value = ok(calculate('3+5/2'));
    Result<int, String> failed = err('Calculation failed');
    

  • Handling multiple results

    Result<bool, Failure> r1 = doSomething1();
    Result<bool, Failure> r2 = doSomething2();
    Result<bool, Failure> r3 = doSomething3();
        
    if ([r1, r2, r3].isAllOk()) {
    	return 'success';
    } else {
    	rollback();
    	return 'failed';
    }
    

• Option

  It is used when there is a result value or there is no result.

  (For the null-safety version of Dart, use nullable types whenever possible.)

  • Basic

    Option<SomeObj> maybeObj = SomeObj.fromJson(json);
        
    SomeObj obj = maybeObj.unwrap() ?? defaultObj;
    SomeObj obj = maybeObj.unwrapOr(orElse: () => defaultObj);
    

  • Construct

    Option<int> value = some(1);
    Option<int> nothing = none();
    

• Either

  • Construct

    Either<int, double> l = left(100);
    Either<int, double> r = right(3.14);
    

Features and bugs

here