packages/wyatt_type_utils/lib/src/either/either_base.dart

@@ -16,7 +16,10 @@
 
 // // ignore_for_file: avoid_positional_boolean_parameters
 
+import 'dart:async';
+
 part 'future_result.dart';
+part 'future_or_result.dart';
 part 'result.dart';
 part 'option.dart';
 

packages/wyatt_type_utils/lib/src/either/future_or_result.dart

@@ -0,0 +1,126 @@
+// Copyright (C) 2022 WYATT GROUP
+// Please see the AUTHORS file for details.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+part of 'either_base.dart';
+
+extension FutureOrResultExtension<T, E> on FutureOr<Result<T, E>> {
+  /// Represents the left side of [Result] class.
+  Future<bool> get isOk => Future.value(this).then((result) => result.isOk);
+
+  /// Represents the right side of [Result] class.
+  Future<bool> get isErr => Future.value(this).then((result) => result.isErr);
+
+  /// Get [U] value, may throw an exception.
+  Future<U> unwrap<U>() =>
+      Future.value(this).then((result) => result.unwrap<U>());
+
+  /// Get **async** [U] value, may throw an exception.
+  ///
+  /// With nullable, `Future(Future(U)) == Future(U)`
+  Future<U> unwrapAsync<U>() =>
+      Future.value(this).then((result) => result.unwrapAsync<U>());
+
+  /// Fold [Ok] and [Err] into the value of one type
+  Future<U> fold<U>(
+    U Function(T value) valueTransformer,
+    U Function(E error) errorTransformer,
+  ) =>
+      Future.value(this)
+          .then((result) => result.fold(valueTransformer, errorTransformer));
+
+  /// Fold [Ok] and [Err] **asynchronously** into the value of one type
+  Future<U> foldAsync<U>(
+    Future<U> Function(T value) valueTransformer,
+    Future<U> Function(E error) errorTransformer,
+  ) =>
+      Future.value(this).then(
+        (result) => result.foldAsync(
+          valueTransformer,
+          errorTransformer,
+        ),
+      );
+
+  /// Swap [Ok] and [Err]
+  Future<Result<E, T>> swap() =>
+      Future.value(this).then((result) => result.swap());
+
+  /// Returns [res] if the [Result] is [Ok], otherwise returns
+  /// the [Err] value of this.
+  Future<Result<U, E>> and<U>(Result<U, E> res) =>
+      Future.value(this).then((result) => result.and(res));
+
+  /// Returns [res] if the [Result] is [Err], otherwise returns
+  /// the [Ok] value of this.
+  Future<Result<T, F>> or<F>(Result<T, F> res) =>
+      Future.value(this).then((result) => result.or(res));
+
+  /// Returns true if the result is an [Ok] or [Err] value containing
+  /// the given value/error.
+  Future<bool> contains<U>(U x) =>
+      Future.value(this).then((result) => result.contains(x));
+
+  /// Returns the contained [Ok] value. Throw [ResultException] on [Err] with
+  /// its content.
+  Future<T> expect(String msg) =>
+      Future.value(this).then((result) => result.expect(msg));
+
+  /// Returns the contained [Err] value. Throw [ResultException] on [Ok] with
+  /// its content.
+  Future<E> expectErr(String msg) =>
+      Future.value(this).then((result) => result.expectErr(msg));
+
+  /// Maps a [Result<T, E>] to [Result<U, E>] by applying a function to a
+  /// contained [Ok] value, leaving an [Err] value untouched.
+  Future<Result<U, E>> map<U>(U Function(T value) mapper) =>
+      Future.value(this).then((result) => result.map(mapper));
+
+  /// Maps a [Result<T, E>] to [Result<U, E>] by applying an **async** function
+  /// to a contained [Ok] value, leaving an [Err] value untouched.
+  Future<Result<U, E>> mapAsync<U>(Future<U> Function(T value) mapper) =>
+      Future.value(this).then((result) => result.mapAsync(mapper));
+
+  /// Maps a [Result<T, E>] to [Result<T, F>] by applying a function to a
+  /// contained [Err] value, leaving an [Ok] value untouched.
+  Future<Result<T, F>> mapErr<F>(F Function(E error) mapper) =>
+      Future.value(this).then((result) => result.mapErr(mapper));
+
+  /// Maps a [Result<T, E>] to [Result<U, E>] by applying an **async** function
+  /// to a contained [Err] value, leaving an [Ok] value untouched.
+  Future<Result<T, F>> mapErrAsync<F>(Future<F> Function(E error) mapper) =>
+      Future.value(this).then((result) => result.mapErrAsync(mapper));
+
+  /// Transforms a [Result<T, E>] to [Result<U, F>] by applying functions to
+  /// contained [Ok] and [Err] values.
+  Future<Result<U, F>> either<U, F>(
+    U Function(T value) valueTransformer,
+    F Function(E error) errorTransformer,
+  ) =>
+      Future.value(this)
+          .then((result) => result.either(valueTransformer, errorTransformer));
+
+  /// Transforms a [Result<T, E>] to [Result<U, F>] by applying **async**
+  /// functions to contained [Ok] and [Err] values.
+  Future<Result<U, F>> eitherAsync<U, F>(
+    Future<U> Function(T value) valueTransformer,
+    Future<F> Function(E error) errorTransformer,
+  ) =>
+      Future.value(this).then(
+        (result) => result.eitherAsync(
+          valueTransformer,
+          errorTransformer,
+        ),
+      );
+}