Option<T>.fromNullable constructor

Option<T>.fromNullable(
  1. T? value
)

Wraps a nullable value: null becomes None, anything else Some.

This is the one place a Dart null turns into absence. Build a Some<T?>(null) directly when null is a present value you want to keep, such as a field explicitly cleared rather than left out.

final missing = Option<String>.fromNullable(null); // None()
final present = Option<String>.fromNullable('John'); // Some(John)

Implementation

factory Option.fromNullable(T? value) {
  return value == null ? None<T>() : Some<T>(value);
}