Resulteles 1.0.2
dotnet add package Resulteles --version 1.0.2
NuGet\Install-Package Resulteles -Version 1.0.2
<PackageReference Include="Resulteles" Version="1.0.2" />
paket add Resulteles --version 1.0.2
#r "nuget: Resulteles, 1.0.2"
// Install Resulteles as a Cake Addin #addin nuget:?package=Resulteles&version=1.0.2 // Install Resulteles as a Cake Tool #tool nuget:?package=Resulteles&version=1.0.2
Resulteles
Resulteles is a practical and lightweight library that define and facilitate the use of a success|failure
data
structure called Result
(aka Either
).
Getting started
NuGet package available:
$ dotnet add package Resulteles
Creating Results
You can create any result using the static methods on Result
// explicitly
var resultSuccess = Result.Ok<int, string>(42);
var resultError = Result.Error<int, string>("Something wrong!");
var processResult = Result.Try(() => { return 1; });
var processAsyncResult = Result.TryAsync(async () => { return await Task.FromResult(2); });
In most of the scenarios you will be using result as a return of a method or function, because of that it implements implicit convert operators from the generic types, reducing the generic type definition noise
public Result<int, string> GetEvenNumber(int number)
{
if (number % 2 is 0)
return number;
else
return $"{number} is not even!";
}
Reading Result Value
The Result
type acts like a blackbox, by default there is no way to just get the typed value mostly because it can be
two things, an Ok
or an Error
.
Result<int, string> result = GetEvenNumber(2);
// return -1 on error
int value1 = result.Match(
n => n,
error => -1
);
result.Switch(
n => Console.WriteLine($"the number {n} is even"),
error => Console.WriteLine(error)
);
// return 0 on error
var value2 = result.DefaultValue(0);
// lazily define the bad case value
var value3 = result.DefaultWith(e => e.Length);
// get the value or throw an exeption
var value4 = result.GetValueOrThrow();
// try/out pattern
if (result.TryGet(out var ok, out var error))
Console.WriteLine($"the number {ok} is even");
else
Console.WriteLine(error);
Operators
Most types you not even need to extract the value, you can just apply functions or combine with other Result
types:
var result1 = Result.Ok<int, string>(1);
// Map the result value only when it is Ok
var result2 = result1.Select(n => n + 1);
// map for ok or error case
Result<string, int> result3 = result1.Select(n => n.ToString(), err => err.Length);
// SelectMany / Bind / FlatMamap
// Nested results transformation
Result<int, string> resultCombined = result1.SelectMany(n => GetEvenNumber(n));
// Zip Results together into a tuple
// only resolves as Ok when both are Ok
Result<(int, int), string> resultZip = result1.Zip(result2);
// Zip Results together
// only resolves as Ok when both are Ok
Result<int, string> resultSum = result1.Zip(result2, (a, b) => a + b);
// Enumerate result, empty when error, singleton when error (see ToArray() also)
IEnumerable<int> resultEnumerable = result1.AsEnumerable();
// LINQ QUERY
// you can use linq query to easily express map and bind
// simple map
var result2Linq = from r in result1 select r + 1;
// combining multiple results (fail fast at first non ok value)
var resultEvenSum =
from a in GetEvenNumber(2)
from b in GetEvenNumber(4)
from c in GetEvenNumber(6)
select a + b + c;
}
Async/Await
This library implements some helpers to seamless deal with async Result code
var result = GetEvenNumber(2);
// async match overload
int value1 = await result.Match(
async n =>
{
await Task.Delay(n);
return n;
},
_ => -1
);
await result.SwitchAsync(
async n => await Console.Out.WriteLineAsync($"the number {n} is even"),
async error => await Console.Error.WriteLineAsync(error)
);
// async projection counterparts
Result<int, string> resultWithDelay = await result.SelectAsync(async n =>
{
await Task.Delay(n);
return n;
});
// Transform Result<Task<int>, string> in a awaitable Task<Result<int, string>>
Result<int, string> resultWithDelay2 = await result.Select(async n =>
{
await Task.Delay(n);
return n;
}).ToTask();
Helper extensions
// result collection
var results = new[] { GetEvenNumber(2), GetEvenNumber(3), GetEvenNumber(4) };
// filter ok values
IEnumerable<int> okResultsOnly = results.GetOkValues(); // [2,4]
// map/reduce based on a result function
var numbers = new[] { 1, 2, 3, 4 };
var calculatedResults = numbers.ChooseResult(x => GetEvenNumber(x)); // [2,4]
// group a collection of result into a Result of collection
// collapse to error if any error is in the collection
Result<IReadOnlyList<int>, string> singleResult = results.GroupResults();
// Transform Result<Task<int>, string> in a awaitable Task<Result<int, string>>
Result<int, string> resultWithDelay2 = await results[0].Select(async n =>
{
await Task.Delay(n);
return n;
}).ToTask();
FluentAssertions Extensions
NuGet package available:
$ dotnet add package Resulteles.FluentAssertions
Alternatives
Product | Versions Compatible and additional computed target framework versions. |
---|---|
.NET | net6.0 is compatible. net6.0-android was computed. net6.0-ios was computed. net6.0-maccatalyst was computed. net6.0-macos was computed. net6.0-tvos was computed. net6.0-windows was computed. net7.0 was computed. net7.0-android was computed. net7.0-ios was computed. net7.0-maccatalyst was computed. net7.0-macos was computed. net7.0-tvos was computed. net7.0-windows was computed. net8.0 was computed. net8.0-android was computed. net8.0-browser was computed. net8.0-ios was computed. net8.0-maccatalyst was computed. net8.0-macos was computed. net8.0-tvos was computed. net8.0-windows was computed. |
-
net6.0
- No dependencies.
NuGet packages (1)
Showing the top 1 NuGet packages that depend on Resulteles:
Package | Downloads |
---|---|
Resulteles.FluentAssertions
FluentAssertions extensions for Resulteles |
GitHub repositories
This package is not used by any popular GitHub repositories.