OptionRecords

This is an an Option type implementaion using C# 9 records which closely follows the Option<'T> API as found in FSharp.Core

Operations against Options can be accessed through static functions or extension methods

Examples of the API can be found in the tests

Some

Construct a new Some

new Some<int>(42);

Option.Some(42);

None

Construct a new None

new None<int>();

Option.None<int>();

Map

Applies a map over the value of an Option

Option.Map(new Some<int>(42), x => x * 2); //Some 84

new Some<int>(42).Map(x => x * 2); //Some 84

Bind

Applies a binder over an Option

Option.Bind(new Some<int>(42), x => new Some<int>(x * 2)); //Some 84

new Some<int>(42).Bind(x => new Some<int>(x * 2)); //Some 84

Get

Gets the value on an Option

Option.Get(new Some<int>(42)); //42

new Some<int>(42).Get(); //42

new None<int>().Get(); //ArgumentException

Default Value

Gets the value on an Option, or returns the default if None

Option.DefaultValue(new Some<int>(42), 0); //42

new Some<int>(42).DefaultValue(0); //42

new None<int>().DefaultValue(0).Dump(); //0

IsSome

Checks if the Option is Some

Option.IsSome(new Some<int>(42)); //True

new Some<int>(42).IsSome(); //True

new None<int>().IsSome(); //False

IsNone

Checks if the Option is None

Option.IsNone(new Some<int>(42)); //False

new Some<int>(42).IsNone(); //False

new None<int>().IsNone(); //True

OfObj

Converts the object into an Option, retuns None if the object is null

Option.OfObj("not a null string"); // Some("not a null string")

Option.OfObj<string>(null); // None<string>()

ToObj

Returns the object from an Option, returns null if the Option is null

Option.ToObj(new Some<string>("not a null string")); // "not a null string"

new Some<string>("not a null string").ToObj(); // "not a null string"

Option.ToObj(new None<string>()); // null

new None<string>().ToObj(); // null

Equality

new None<int>() == new None<int>() //True

new None<int>() == new Some<int>(42) //False

new Some<int>(42) == new Some<int>(42) //True

new Some<int>(42) == new Some<int>(99) //False