Tell me about predictive code completion

Predictive code completion in Xcode 16 is a significant enhancement that leverages a unique model specifically trained for Swift and Apple SDKs. This model uses your project symbols to customize suggestions and runs locally on your Mac, ensuring your code remains private and providing fast results even when offline. The predictive completions suggest whole statements and methods based on the surrounding code, and you can accept these suggestions by pressing the tab key or expand the entire prediction by holding the option key.

The completion model is powered by Apple silicon and machine learning enhancements, automatically updating with the latest SDK and language changes. This feature is designed to improve productivity by transforming ideas into code more efficiently, using natural language and context from your comments and variable names to inform predictions.

For more details, you can refer to the Platforms State of the Union (21:10) session, which discusses the new predictive code completion and its integration with Xcode 16.