Minor Refactoring (#43)

* Add more strict conformance for base protocol types

* Use opaque parameter

* Use shorthands for unwrapping optinals

* Use closure type inference

Author: ra1028

README.md

@@ -1157,7 +1157,7 @@ class MockAPIClient: APIClientProtocol {
     var response: Book?
 
     func fetchBook(isbn: String) async throws -> Book {
-        guard let response = response else {
+        guard let response else {
             throw URLError(.unknown)
         }
         return response

Sources/Atoms/Context/AtomContext.swift

@@ -77,7 +77,7 @@ public protocol AtomContext {
     /// ```
     ///
     /// - Parameter atom: An atom that associates the value.
-    func reset<Node: Atom>(_ atom: Node)
+    func reset(_ atom: some Atom)
 }
 
 public extension AtomContext {

Sources/Atoms/Context/AtomTestContext.swift

@@ -167,7 +167,7 @@ public struct AtomTestContext: AtomWatchableContext {
     /// ```
     ///
     /// - Parameter atom: An atom that associates the value.
-    public func reset<Node: Atom>(_ atom: Node) {
+    public func reset(_ atom: some Atom) {
         state.store.reset(atom)
     }
 

Sources/Atoms/Context/AtomTransactionContext.swift

@@ -104,7 +104,7 @@ public struct AtomTransactionContext<Coordinator>: AtomWatchableContext {
     ///
     /// - Parameter atom: An atom that associates the value.
     @inlinable
-    public func reset<Node: Atom>(_ atom: Node) {
+    public func reset(_ atom: some Atom) {
         _store.reset(atom)
     }
 

Sources/Atoms/Context/AtomViewContext.swift

@@ -103,7 +103,7 @@ public struct AtomViewContext: AtomWatchableContext {
     ///
     /// - Parameter atom: An atom that associates the value.
     @inlinable
-    public func reset<Node: Atom>(_ atom: Node) {
+    public func reset(_ atom: some Atom) {
         _store.reset(atom)
     }
 

Sources/Atoms/Core/AtomCache.swift

@@ -1,22 +1,28 @@
 @MainActor
-internal protocol AtomCacheBase {
+internal protocol AtomCacheProtocol: CustomStringConvertible {
+    associatedtype Node: Atom
+
+    var atom: Node { get set }
+    var value: Node.Loader.Value? { get set }
     var shouldKeepAlive: Bool { get }
 
     func reset(with store: StoreContext)
 }
 
-internal struct AtomCache<Node: Atom>: AtomCacheBase, CustomStringConvertible {
+internal extension AtomCacheProtocol {
+    var description: String {
+        value.map { "\($0)" } ?? "nil"
+    }
+}
+
+internal struct AtomCache<Node: Atom>: AtomCacheProtocol {
     var atom: Node
     var value: Node.Loader.Value?
 
     var shouldKeepAlive: Bool {
         Node.shouldKeepAlive
     }
 
-    var description: String {
-        value.map { "\($0)" } ?? "nil"
-    }
-
     func reset(with store: StoreContext) {
         store.reset(atom)
     }

Sources/Atoms/Core/AtomState.swift

@@ -1,9 +1,12 @@
 @MainActor
-internal protocol AtomStateBase {
-    var transaction: Transaction? { get nonmutating set }
+internal protocol AtomStateProtocol: AnyObject {
+    associatedtype Coordinator
+
+    var coordinator: Coordinator { get }
+    var transaction: Transaction? { get set }
 }
 
-internal final class AtomState<Coordinator>: AtomStateBase {
+internal final class AtomState<Coordinator>: AtomStateProtocol {
     let coordinator: Coordinator
     var transaction: Transaction?
 

Sources/Atoms/Core/Loader/AsyncSequenceAtomLoader.swift

@@ -44,7 +44,7 @@ public struct AsyncSequenceAtomLoader<Node: AsyncSequenceAtom>: RefreshableAtomL
     /// and returns a final value.
     public func refresh(context: Context) async -> Value {
         let sequence = context.transaction(atom.sequence)
-        let task = Task { () -> Value in
+        let task = Task {
             var phase = Value.suspending
 
             do {

Sources/Atoms/Core/Loader/ObservableObjectAtomLoader.swift

@@ -24,7 +24,7 @@ public struct ObservableObjectAtomLoader<Node: ObservableObjectAtom>: AtomLoader
     /// Handles updates or cancellation of the passed value.
     public func handle(context: Context, with object: Value) -> Value {
         let cancellable = object.objectWillChange.sink { [weak object] _ in
-            guard let object = object else {
+            guard let object else {
                 return
             }
 

Sources/Atoms/Core/Loader/PublisherAtomLoader.swift

@@ -38,7 +38,7 @@ public struct PublisherAtomLoader<Node: PublisherAtom>: RefreshableAtomLoader {
     /// Refreshes and awaits until the asynchronous is finished and returns a final value.
     public func refresh(context: Context) async -> Value {
         let results = context.transaction(atom.publisher).results
-        let task = Task { () -> Value in
+        let task = Task {
             var phase = Value.suspending
 
             for await result in results {