Add readme and license files

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Ugochukwu Mmirikwe
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Package.swift

@@ -1,5 +1,4 @@
 // swift-tools-version: 5.9
-// The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
 import CompilerPluginSupport
@@ -8,7 +7,6 @@ let package = Package(
     name: "CopyableMacro",
     platforms: [.macOS(.v10_15), .iOS(.v13), .tvOS(.v13), .watchOS(.v6), .macCatalyst(.v13)],
     products: [
-        // Products define the executables and libraries a package produces, making them visible to other packages.
         .library(
             name: "CopyableMacro",
             targets: ["CopyableMacroMacros"]
@@ -19,28 +17,20 @@ let package = Package(
         ),
     ],
     dependencies: [
-        // Depend on the Swift 5.9 release of SwiftSyntax
         .package(url: "https://github.com/apple/swift-syntax.git", from: "509.0.0"),
     ],
     targets: [
-        // Targets are the basic building blocks of a package, defining a module or a test suite.
-        // Targets can depend on other targets in this package and products from dependencies.
-        // Macro implementation that performs the source transformation of a macro.
         .macro(
             name: "CopyableMacroMacros",
             dependencies: [
                 .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
                 .product(name: "SwiftCompilerPlugin", package: "swift-syntax")
             ]
         ),
-
-        // Library that exposes a macro as part of its API, which is used in client programs.
         .target(name: "CopyableMacro", dependencies: ["CopyableMacroMacros"]),
 
         // A client of the library, which is able to use the macro in its own code.
         .executableTarget(name: "CopyableMacroClient", dependencies: ["CopyableMacro"]),
-
-        // A test target used to develop the macro implementation.
         .testTarget(
             name: "CopyableMacroTests",
             dependencies: [

README.md

@@ -0,0 +1,96 @@
+# Overview
+
+`SwiftCopyableMacro` is a very simple Swift macro library that auto-generates a `copy()` function for structs at compile time, which takes all the public properties of the struct as arguments in the function, enabling a runtime ability to elegantly duplicate an instance of the struct and setting new values for any or all these (even immutable) properties at the same time, similar to what [Kotlin's `data class`](https://kotlinlang.org/docs/data-classes.html#copying) offers.
+
+The only effort required is to mark the structs with a custom `@Copyable` annotation and the structs are automatically injected with a `copy()` method inside. For example:
+
+```swift
+@Copyable // <= annotation is used here
+struct User {
+    let name: String
+    let age: Int
+}
+```
+
+automatically updates the struct at compile time (which happens instantly if editing the file inside of Xcode) as follows:
+
+```swift
+struct User {
+    let name: String
+    let age: Int
+
+    // Notice the arguments for the function 👇
+    func copy(name: String? = nil, age: Int? = nil) -> Self {
+        .init(
+            name: name ?? self.name
+            age: age ?? self.age
+        )
+    }
+}
+```
+
+This struct can now be used at a call site like so:
+
+```swift
+let ugo = User(name: "Ugo", age: 30)
+print(ugo) // Ugo(name: "Ugo", age: 30)
+
+let ugoAsJack = ugo.copy(name: "Jack") // <= .copy() is used here
+print(ugoAsJack) // Ugo(name: "Jack", age: 30)
+
+let ugoIsOlder = ugo.copy(age: 34) // <= .copy() is used here
+print(ugoIsOlder) // Ugo(name: "Ugo", age: 34)
+print(ugoAsJack) // Ugo(name: "Jack", age: 30)
+
+let jackIsYounger = ugoAsJack.copy(age: 25) // <= .copy() is used here
+print(jackIsYounger) // Ugo(name: "Jack", age: 25)
+```
+
+Xcode will even offer autocomplete listing all the properties declared in the struct as parameters in this `.copy(...)` function.
+
+# Installation
+This macro is available for installation via the Swift Package Manager (SPM) as follows:
+
+## Xcode
+1. In Xcode, select the menu: `File` → `Add Package Dependencies…` to launch the SPM dialog;
+2. in the "Search or Enter Package URL" text field, enter the package URL: https://github.com/ugommirikwe/SwiftCopyableMacro;
+3. in "Dependency Rule" select "Branch";
+4. in the "Branch" text field enter the value "main"
+5. select the project to add the 
+
+## package.swift
+For projects that use a `package.swift` file to manage their SPM dependencies, you can add it to your `package.swift` file like so:
+
+```swift
+dependencies: [
+    .package(url: "https://github.com/ugommirikwe/SwiftCopyableMacro", .branch("main"))
+]
+```
+
+And then add the product to all targets that use CopyableMacro:
+
+```swift
+...
+targets: [
+    .target(
+        name: "<NameOfYourTarget>", 
+        dependencies: ["CopyableMacro"],
+    )
+]
+```
+
+# Import & Usage
+The [overview](#overview) section above already describes how to use the macro: prepend your struct name with the annotation `@Copyable` and that's all. Xcode 15+ should automatically add the import at the top of the file for you. Otherwise, go ahead and add it as follows to clear any errors in your file:
+
+```swift
+import CopyableMacro
+```
+
+# Pre-Release
+Please note that this code is still in pre-release stage and should be carefully evaluated before using in your production code.
+
+# Feedback and Issues
+Feel free to submit any issues or suggestions. Pull requests are also welcomed. 
+
+# License
+SwiftCopyableMacro is available under the MIT license. See the [LICENSE](LICENSE) file for more info.