Examples demonstrating interoperability between Zig and Swift on macOS.
- Zig 0.14.0 or later
- Xcode Command Line Tools (for Swift compiler)
- macOS
This repository contains four examples showing different approaches to Zig-Swift interop:
In this example, Swift (using AppKit) controls the application lifecycle and calls functions implemented in Zig.
Structure:
- Swift creates the macOS app and UI
- Zig provides functions that Swift can call
- The main entry point is in Swift
Build and run:
# Run the example
zig build run-swift-appkit
# Build only (without running)
zig build -Dexample=swift-appkit
# Default build/run (backward compatible)
zig build
zig build runKey files:
examples/swift-appkit/macos/main.swift- Swift AppKit app entry pointexamples/swift-appkit/src/main.zig- Zig functions exported for Swiftexamples/swift-appkit/include/x.h- C header for Swift-Zig bridge
In this example, SwiftUI controls the application lifecycle and calls functions implemented in Zig.
Structure:
- SwiftUI creates the macOS app with modern declarative UI
- Zig provides functions that SwiftUI can call
- The main entry point is in SwiftUI using
@main
Build and run:
# Run the example
zig build run-swiftui-main
# Build only (without running)
zig build -Dexample=swiftui-mainKey files:
examples/swiftui-main/macos/main.swift- SwiftUI app entry pointexamples/swiftui-main/src/main.zig- Zig functions exported for SwiftUIexamples/swiftui-main/include/x.h- C header for SwiftUI-Zig bridge
In this example, Zig controls the application lifecycle and initializes a Swift AppKit UI.
Structure:
- Zig contains the main entry point
- Swift provides UI functions that Zig calls
- Demonstrates Zig driving a Swift/Cocoa application
Build and run:
# Run the example
zig build run-zig-appkit
# Build only (without running)
zig build -Dexample=zig-appkitKey files:
examples/zig-appkit/src/main.zig- Zig main entry pointexamples/zig-appkit/macos/ui.swift- Swift AppKit UI functions exported for Zigexamples/zig-appkit/include/swift_ui.h- C header for Zig-Swift bridge
In this example, Zig controls the application lifecycle and launches a SwiftUI app with advanced interop demonstrations.
Structure:
- Zig contains the main entry point
- SwiftUI provides the UI with bidirectional communication
- Demonstrates Zig driving a modern SwiftUI application
- Shows different callback patterns and UI responsiveness
Features:
- Multiple callback patterns: Demonstrates sync blocking, async task, and immediate UI update patterns
- Progress tracking: Shows how Zig can perform long-running tasks while updating SwiftUI progress bars
- Responsive UI: Maintains full UI responsiveness during heavy Zig computation
Build and run:
# Run the example
zig build run-zig-swiftui
# Build only (without running)
zig build -Dexample=zig-swiftuiKey files:
examples/zig-swiftui/src/main.zig- Zig main entry point with callbacks and progress demoexamples/zig-swiftui/macos/ui.swift- SwiftUI app demonstrating various interop patternsexamples/zig-swiftui/include/swiftui_bridge.h- C header for bidirectional communication
All examples use C ABI as the bridge between Zig and Swift:
Zig → Swift:
- Zig functions use
export fnto be callable from Swift - Swift imports these functions via C headers or
@_silgen_name
Swift → Zig:
- Swift functions use
@_cdecl("function_name")to be callable from Zig - Zig imports these functions using
extern fndeclarations
Key patterns demonstrated:
- Swift AppKit/SwiftUI as main: Zig provides a static library that Swift links against
- Zig as main: Zig compiles to object file and links with Swift code using
swiftc - Bidirectional communication: Both languages can call each other's functions
- Async patterns: Maintaining UI responsiveness during heavy computation
- UI frameworks: Examples using both AppKit (traditional) and SwiftUI (modern)
To remove all build artifacts:
zig build cleanzig-swift-example/
├── build.zig # Build configuration
├── examples/
│ ├── swift-appkit/ # Swift AppKit controls app lifecycle
│ │ ├── include/ # C headers
│ │ ├── macos/ # Swift source and Info.plist
│ │ └── src/ # Zig source
│ ├── swiftui-main/ # SwiftUI controls app lifecycle
│ │ ├── include/ # C headers
│ │ ├── macos/ # SwiftUI source and Info.plist
│ │ └── src/ # Zig source
│ ├── zig-appkit/ # Zig controls AppKit app lifecycle
│ │ ├── include/ # C headers
│ │ ├── macos/ # Swift source and Info.plist
│ │ └── src/ # Zig source
│ └── zig-swiftui/ # Zig controls SwiftUI app lifecycle
│ ├── include/ # C headers
│ ├── macos/ # SwiftUI source and Info.plist
│ └── src/ # Zig source
└── zig-out/ # Build output (generated)