From 58effa0ebdb938aa64977e2109fa7714f53978c9 Mon Sep 17 00:00:00 2001
From: Kirill Bubochkin <ookami.kb@gmail.com>
Date: Mon, 3 Jun 2024 18:28:24 +0200
Subject: [PATCH] feat: revert unwrap (#28)

---
 lib/src/either/try_either.dart   | 29 +++++++++++++++++++----------
 test/either/try_either_test.dart |  8 ++++----
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/lib/src/either/try_either.dart b/lib/src/either/try_either.dart
index 2dfcd3d..e5718f2 100644
--- a/lib/src/either/try_either.dart
+++ b/lib/src/either/try_either.dart
@@ -4,18 +4,17 @@ import 'package:dfunc/dfunc.dart';
 
 typedef Result<T> = Either<Exception, T>;
 typedef AsyncResult<T> = Future<Result<T>>;
-
-extension ResultUnwrap<R> on Result<R> {
-  R unwrap() => fold((e) => throw e, (r) => r);
-}
+typedef BindEither = T Function<T>(Result<T>);
 
 /// Wraps [block] function into try..catch and returns [Right] with the
 /// result. In case of any [Exception] returns [Left] with the exception.
 ///
 /// It doesn't catch [Error]s as it usually means a bug in the code.
-Result<T> tryEither<T>(T Function() block) {
+Result<T> tryEither<T>(T Function(BindEither bind) block) {
+  A bind<A>(Result<A> either) => either.fold((e) => throw e, identity);
+
   try {
-    return Either.right(block());
+    return Either.right(block(bind));
   } on Exception catch (error) {
     return Either.left(error);
   }
@@ -26,19 +25,29 @@ Result<T> tryEither<T>(T Function() block) {
 /// with [Left] containing the exception.
 ///
 /// It doesn't catch [Error]s as it usually means a bug in the code.
-AsyncResult<T> tryEitherAsync<T>(FutureOr<T> Function() block) async {
+AsyncResult<T> tryEitherAsync<T>(
+  FutureOr<T> Function(BindEither bind) block,
+) async {
   try {
-    return Either.right(await block());
+    A bind<A>(Result<A> either) => either.fold((e) => throw e, identity);
+
+    return Either.right(await block(bind));
   } on Exception catch (error) {
     return Either.left(error);
   }
 }
 
 extension FutureToEitherExt<T> on Future<T> {
-  AsyncResult<T> toEither() => tryEitherAsync(() => this);
+  AsyncResult<T> toEither() async {
+    try {
+      return Either.right(await this);
+    } on Exception catch (error) {
+      return Either.left(error);
+    }
+  }
 }
 
 extension IterableResultExt<T> on Iterable<Result<T>> {
   Result<List<T>> sequence() =>
-      tryEither(() => this.map((e) => e.unwrap()).toList());
+      tryEither((bind) => this.map((e) => bind(e)).toList());
 }
diff --git a/test/either/try_either_test.dart b/test/either/try_either_test.dart
index 46cbecc..641dd86 100644
--- a/test/either/try_either_test.dart
+++ b/test/either/try_either_test.dart
@@ -4,13 +4,13 @@ import 'package:test/test.dart';
 void main() {
   group('tryEither', () {
     test('returns right', () {
-      final result = tryEither(() => int.parse('123'));
+      final result = tryEither((_) => int.parse('123'));
 
       expect(result, const Result<int>.right(123));
     });
 
     test('returns left on exception', () {
-      final result = tryEither(() => int.parse('wrong'));
+      final result = tryEither((_) => int.parse('wrong'));
 
       expect(result.isLeft(), true);
     });
@@ -18,13 +18,13 @@ void main() {
 
   group('tryEitherAsync', () {
     test('returns right', () async {
-      final result = await tryEitherAsync(() => int.parse('123'));
+      final result = await tryEitherAsync((_) => int.parse('123'));
 
       expect(result, const Result<int>.right(123));
     });
 
     test('returns left on exception', () async {
-      final result = await tryEitherAsync(() => int.parse('wrong'));
+      final result = await tryEitherAsync((_) => int.parse('wrong'));
 
       expect(result.isLeft(), true);
     });