How to use modern Swift Macros to generate boilerplate code in iOS projects?
The introduction of macros in Swift has opened up new possibilities for compile-time metaprogramming. Macros allow you to automate routine tasks, reducing the amount of boilerplate code without compromising app performance. They execute directly during project build time in an isolated environment, checking types and syntax even before the executable file is run.
To create your own macro, you need to set up a specialized Swift package containing the macro compiler and the client part. There are two main types of macros: declarative macros, which generate new code around existing entities, and expressive macros, which replace specific expressions. For example, a macro can automatically create a Codable protocol implementation for complex data structures or generate methods for working with databases.
The process of integrating and using macros looks as follows:
Using macros requires careful attention to project compilation speed. Since each macro analyzes the abstract syntax tree of the source code, an excessive number of complex macros can slow down the build. Nevertheless, the competent use of this technology makes the codebase of iOS applications cleaner, more expressive, and safer.