swift-immutable

swift-immutable is a Swift macro package that extends pure structs with a clone method, copy swift struct that inspired by Kotlin's data class copy function. This package aims to facilitate immutable programming in Swift, particularly beneficial when working with SwiftUI.

Features

• Extend pure structs with a clone method, allowing for easy modification of immutable structures.
• Syntactic sugar for numeric types, String, and Bool, enabling convenient operations like increment/decrement and string manipulation.

Getting Started

To start using swift-immutable in your Swift projects, follow these steps:

Installation

swift-immutable is available through Swift Package Manager (SPM). To include it in your project, you need to add the package dependency to your Package.swift file.

1. Open your Swift project in Xcode.
2. Navigate to File > Swift Packages > Add Package Dependency....
3. Paste the following package URL into the search bar:

    dependencies: [
      .package(url: "https://github.com/rayeddev/swift-immutable.git", from: "<#latest swift-immutable tag#>"),
    ],

4. Follow the prompts to add the package to your project.

Examples

Basic Cloning

import SwiftImmutable


// Pure struct
@Clone
struct Person {
    let name: String
    let age: Int
    let active: Bool
    let status: String
}

var person = Person(name: "Tom", age: 20, active: false, status: "free to hire")

// Modify properties with clone
person = person.clone(active: true, status: "not available")

Numeric, String, and Bool Modifiers

// age increment
person = person.clone(inc: .age(1))

// Toggle active status
person = person.clone(toggle: .active)

// Add prefix to name
person = person.clone(prefix: .name("Mr. "))

// Append suffix to name
person = person.clone(suffix: .name(" legend"))

Working with Collections

var persons = [Person]()

// Deactivate all
persons = persons.map { $0.clone(toggle: .active) }

// Update status and toggle active
persons = persons.map { $0.clone(status: "hire", toggle: .active) }

Limitations swift-immutable is designed for pure structs that have public or internal let members without initializers. This constraint ensures that your data structures are truly immutable and encourages best practices in immutable programming.