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lib/utils/result.dart

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+// Copyright 2024 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// Utility class to wrap result data
+///
+/// Evaluate the result using a switch statement:
+/// ```dart
+/// switch (result) {
+///   case Ok(): {
+///     print(result.value);
+///   }
+///   case Error(): {
+///     print(result.error);
+///   }
+/// }
+/// ```
+sealed class Result<T> {
+  const Result();
+
+  /// Creates a successful [Result], completed with the specified [value].
+  const factory Result.ok(T value) = Ok._;
+
+  /// Creates an error [Result], completed with the specified [error].
+  const factory Result.error(Exception error) = Error._;
+}
+
+/// Subclass of Result for values
+final class Ok<T> extends Result<T> {
+  const Ok._(this.value);
+
+  /// Returned value in result
+  final T value;
+
+  @override
+  String toString() => 'Result<$T>.ok($value)';
+}
+
+/// Subclass of Result for errors
+final class Error<T> extends Result<T> {
+  const Error._(this.error);
+
+  /// Returned error in result
+  final Exception error;
+
+  @override
+  String toString() => 'Result<$T>.error($error)';
+}