# `Geekeey.Extensions.Result`

Result is a .NET library which provides a Result<T> type for representing the outcome of operations in C#. It offers a
clean and concise way to handle success and failure scenarios, promoting better error handling and code readability.

## Features

- **Success and Failure States:** Represent successful outcomes with a value (`Prelude.Success()`) or failures with an
  error (`Prelude.Failure()`).
- **Immutability:** `Result<T>` objects are immutable, ensuring thread safety and preventing accidental modification.
- **Chaining Operations:** Methods like `Map` and `Then` allow for chaining operations on successful results, promoting
  a functional programming style.

## Getting Started

### Install the NuGet package:

```
dotnet add package Geekeey.Extensions.Result
```

You may need to add our NuGet Feed to your `nuget.config` this can be done by adding the following lines

```xml
<packageSources>
	<add key="geekeey" value="https://git.geekeey.de/api/packages/geekeey/nuget/index.json" />
</packageSources>
```

### Configure

The package adds a global using for the functions in the `Prelude` class when the `ImplicitUsings` is enabled in
the `.csproj` file. This global using is recommended but can also be removed, by removing
the `Geekeey.Extensions.Result.Prelude` value from the item group `<Usings>`. For more information about that see
the `Project.props` file inside the project tree.

### Usage

```csharp
public Result<int> Divide(int dividend, int divisor)
{
  if (divisor == 0)
  {
    return Prelude.Failure<int>("Division by zero");
  }

  return Prelude.Success(dividend / divisor);
}

if (result.IsSuccess)
{
  Console.WriteLine("Result: " + result.Value);
}
else
{
  Console.WriteLine("Error: " + result.Error);
}
```

```csharp
_ = await Prelude.Try(() => File.ReadAllLines("i_do_not_exist.txt"))
	.ThenAsync(static async Task<Result<IReadOnlyList<int>>> (list) =>
	{
		using var client = new HttpClient();
		Task<Result<int>> DoSomeThing(string line)
			=> Prelude.TryAsync(() => client.GetAsync(line))
				.Map(static async response => int.Parse(await response.Content.ReadAsStringAsync()));
		var results = await Task.WhenAll(list.Select(DoSomeThing).ToArray());
		return results.Join();
	});
```