macros_rule the_world! - Alvin Ramskogler - Rust Linz, May 2022

Discover the power of declarative macros in Rust, exploring their convenience, hygiene, and flexibility, as well as debugging techniques and use cases for everyday coding and advanced programming tasks.

Key takeaways
  • Declarative macros in Rust are more powerful and convenient than C macros, as they automatically import and handle syntax differences.
  • Macro hygiene is a problem in C macros, where macros can affect other macros’ behavior. Rust’s declarative macros solve this issue.
  • Rust macros can have parameters, be recursive, and use patterns like repetition and alternation.
  • Macros can be used to generate code at compile-time, making them useful for tasks like string formatting and syntax validation.
  • Macros can be debugged like regular Rust code, and the cargo-expand tool allows examining the generated code.
  • Rust has two types of macros: declarative and procedural. Declarative macros are built-in and easier to use, while procedural macros are more powerful but require advanced knowledge.
  • Macros can be used for everyday coding tasks, such as string formatting and code generation, and can make code more concise and readable.
  • Rust’s macro_rules! syntax allows defining macros with a simple and expressive syntax.
  • Macros can be made more powerful and flexible by using features like repetition, alternation, and patterns.
  • Rust’s lazy-static feature allows creating macros that can be used across files and modules.
  • Debugging Rust macros can be complex and requires understanding of the compiler’s inner workings.
  • Macros can be used to generate code that is difficult or impossible to write by hand, making them a powerful tool for advanced coding tasks.