NOptional

NOptional is a very close clone of Java's Optional type ported to .NET. For further references, see Java documentation. I aimed for a very close implementation, so the original documentation can be used for details.

Usage

Creation

Use either Optional.Empty<T> or Optional.Of<T>(T value) to create a new Instance of your Optional.

IOptional<string> emptyOptional = Optional.Empty<string>();
IOptional<string> filledOptional = Optional.Of("MyString");

When you are using this in a scenario where you don't know, whether you actually have a value or not, use Optional.OfNullable<T>(T value)

private IOptional<T> Create<T>(T value)
{
  return Optional.OfNullable(value);
}

Accessing Value of Optional

Never access IOptional.Value without prior checking whether a value is preset using IOptional.HasValue(). Ideally, you would never use the property-accessor directly. Instead, use any of the IOptional.Or... methods.

General usage

To quote the original documentation:

Optional is primarily intended for use as a method return type where there is a clear need to represent "no result," and where using null is likely to cause errors. A variable whose type is Optional should never itself be null; it should always point to an Optional instance.

Installation

NOptional is available via nuget: NOptional via nuget

You can use either Package Manager or .NET CLI to install it

Package Manager:

Install-Package NOptional -Version LATEST_VERSION

.NET CLI: