Procedural macros in Rust

Procedural macros in Rust, commonly encountered in projects such as Serde, Rocket, and wasm-bindgen, are a form of metaprogramming that allows developers to generate Rust code at compile time by analyzing and transforming Rust code using the abstract syntax tree (AST). Unlike declarative macros, which perform text substitution based on code patterns, procedural macros offer more power by inspecting the provided code before generating output. There are three types of procedural macros: derive, function-like, and attribute macros, each operating on TokenStreams but in distinct ways. A derive macro, for example, can be created to print information about the structs, enums, or unions it is attached to by parsing the TokenStream with the syn crate and generating new Rust code using the quote crate. Though powerful, procedural macros are complex and require significant understanding, with resources such as Alex Crichton's Rust blog post and the Rust Book's section on macros providing further insights. For hands-on experience, workshops like David Tolnay’s "Rust Latam: procedural macros workshop" offer practical projects. Additionally, tools like LogRocket can aid in monitoring and debugging Rust applications by providing replay capabilities and performance tracking.