Issue 167.  June 13th 2024

What's new in Swift 6.0?

Swift 6.0 brings a significant update to the Swift programming language, with a strong focus on improving concurrency safety.

Here's a breakdown of the key changes:

• Safer Concurrency by Default: Enforces writing code that avoids data races.
• Enhanced Concurrency Features: Isolation regions and the sending keyword provide better tools for developers to write safe and efficient concurrent code.

New Language Features:

• count(where:) for filtering and counting elements in collections (SE-0220).
• Typed throws, to specify the types of errors a function can throw (SE-0413).
• Support for non-copyable types in generics and protocols (SE-0427, SE-0432). 128-bit integer types for wider numeric ranges (SE-0425).

Introduction to Swift Service Lifecycle

Swift Service Lifecycle, a library for simplified application startup and shutdown with freeing resources before exiting.

Core Concepts:

• Define services (long-running tasks) with Service protocol.
• Manage multiple services concurrently with ServiceGroup.
• Gracefully shut down services using gracefulShutdown.

It provides efficient resource management through graceful shutdowns, reusable shutdown logic across applications, and simplified concurrent task management.

Designing a Declarative API

A custom validator type in Swift for user input validation. It leverages declarative programming for clear logic and structure, reducing control flow concerns. Notably, this approach is applicable beyond UI development.

Key Concepts:

• Define validation rules using predicates (functions checking validity).
• Chain rule methods for a declarative and DSL-like style.
• Combine validators with custom operators (AND, OR) for complex logic.

This article demonstrates how to design a declarative API using a validator example, promoting code readability, maintainability, and flexibility.