feat: Type-erased mutations

README.md

@@ -6,7 +6,7 @@
 
 [![iOS Version](https://img.shields.io/badge/iOS_Version->=_13.0-brightgreen?logo=apple&logoColor=green)]() 
 [![Swift Version](https://img.shields.io/badge/Swift_Version-6.0-green?logo=swift)](https://docs.swift.org/swift-book/)
-[![Contains Test](https://img.shields.io/badge/Tests-69%25_coverage-blue)]()
+[![Contains Test](https://img.shields.io/badge/Tests-83%25_coverage-blue)]()
 [![Dependency Manager](https://img.shields.io/badge/Dependency_Manager-SPM-red)](#swiftpackagemanager)
 
 TBD: updated description

Sources/GoodReactor/Core/DataFetchingState.swift

@@ -0,0 +1,108 @@
+//
+//  DataFetchingState.swift
+//  GoodReactor
+//
+//  Created by Filip Šašala on 21/10/2025.
+//
+
+@_spi(ReactorExperimental) public enum DataFetchingState<T, E: Error> {
+
+    case idle
+    case loading
+    case success(T)
+    case failure(E)
+
+}
+
+@_spi(ReactorExperimental) extension DataFetchingState {
+
+    public var isIdle: Bool {
+        switch self {
+        case .idle: true
+        default: false
+        }
+    }
+
+    public var isLoading: Bool {
+        switch self {
+        case .loading: true
+        default: false
+        }
+    }
+
+    public var isSuccess: Bool {
+        switch self {
+            case .success: true
+            default: false
+        }
+    }
+
+    public var isFailure: Bool {
+        switch self {
+        case .failure: true
+        default: false
+        }
+    }
+
+    public var successValue: T? {
+        if case .success(let value) = self {
+            return value
+        }
+        return nil
+    }
+
+    public var errorValue: E? {
+        if case .failure(let error) = self {
+            return error
+        }
+        return nil
+    }
+
+}
+
+@_spi(ReactorExperimental) extension DataFetchingState: Sendable where T: Sendable {}
+
+@_spi(ReactorExperimental) extension DataFetchingState: Equatable where T: Equatable {
+
+    nonisolated public static func == (lhs: Self, rhs: Self) -> Bool {
+        switch lhs {
+        case .idle:
+            switch rhs {
+            case .idle:
+                return true
+
+            default:
+                return false
+            }
+
+        case .loading:
+            switch rhs {
+            case .loading:
+                return true
+
+            default:
+                return false
+            }
+
+        case .success(let lhsValue):
+            switch rhs {
+            case .success(let rhsValue):
+                return lhsValue == rhsValue
+
+            default:
+                return false
+            }
+
+        case .failure(let lhsError):
+            switch rhs {
+            case .failure(let rhsError):
+                // TODO: improve error equality
+                return lhsError.localizedDescription == rhsError.localizedDescription
+
+            default:
+                return false
+            }
+        }
+    }
+
+}

Sources/GoodReactor/Core/Erased/AnyMutation.swift

@@ -0,0 +1,20 @@
+//
+//  Mutation.swift
+//  GoodReactor
+//
+//  Created by Filip Šašala on 01/10/2025.
+//
+
+public struct AnyMutation: Sendable {
+
+    internal let `enum`: (Any & Sendable)
+
+    internal init<E: Sendable>(_ `enum`: E) {
+        self.enum = `enum`
+    }
+
+    internal func `as`<T>(_: T.Type) -> T? {
+        `enum` as? T
+    }
+
+}