Tiny Optional: A Lightweight C# Optional Type

This library provides a simple Optional (a.k.a. “Maybe”) type for C#. It allows you to express the presence or absence of a value without resorting to null. If an Optional<T> has a value, you can safely work with that value; if it doesn’t, the library’s methods help gracefully handle the “no value” scenario.

Why Use an Optional Type?

• Clarity: Instead of passing null or returning null, an Optional<T> signals explicitly that the result might be absent.
• Safety: Avoid NullReferenceException by forcing the developer to deal with the possibility of an empty value.
• Functional Style: Where, Select, SelectMany, IfPresent, etc., allow fluent transformations and checks.

Installation

dotnet add package TinyOptional

Getting Started

Creating Optionals

// Throws an ArgumentNullException if `value` is null var maybeTen = Optional<int>.Of(10); // Allows null but returns an empty Optional var maybeName = Optional<string>.OfNullable(userName); // A straightforward empty Optional var none = Optional<int>.Empty();

Unboxing an optional

This is a simple and wrong way of unboxing an optional:

var maybeName = Optional<string>.OfNullable(userName); if (maybeName.IsPresent()) { var name = maybeName.Get(); }

While possible, this is not the suggested workflow, as it would be a glorified, more verbose null-check.

Instead...

Unboxing with fallback or error handling

var maybeName = Optional<string>.OfNullable(userName); // Simple fallback var name = maybeName.OrElse("No name provided"); // In case the fallback is expensive to compute var name2 = maybeName.OrElseGet(() => GenerateRandomName()); // In case no fallback is possible var name3 = empty.OrElseThrow(() => new Exception("Name is required"));

Filtering and mapping

It is possible to apply a clause to an Optional, returning empty if the predicate fails.