- name
- rust-macros
- description
- Master Rust macros - declarative and procedural macros
- sasmp_version
- 1.3.0
- bonded_agent
- rust-type-system-agent
- bond_type
- SECONDARY_BOND
- version
- 1.0.0
Rust Macros Skill
Master Rust's macro system: declarative macros (macro_rules!) and procedural macros.
Quick Start
Declarative Macros
macro_rules! vec_of_strings {
($($x:expr),* $(,)?) => {
vec![$($x.to_string()),*]
};
}
let v = vec_of_strings!["a", "b", "c"];
Fragment Specifiers
| Specifier | Matches |
|---|
ident | Identifier |
expr | Expression |
ty | Type |
pat | Pattern |
tt | Token tree |
literal | Literal |
Repetition
macro_rules! hashmap {
($($key:expr => $value:expr),* $(,)?) => {{
let mut map = std::collections::HashMap::new();
$(map.insert($key, $value);)*
map
}};
}
let m = hashmap! { "one" => 1, "two" => 2 };
Procedural Macros
[lib]
proc-macro = true
[dependencies]
syn = { version = "2", features = ["full"] }
quote = "1"
Derive Macro
use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, DeriveInput};
#[proc_macro_derive(HelloMacro)]
pub fn hello_derive(input: TokenStream) -> TokenStream {
let input = parse_macro_input!(input as DeriveInput);
let name = input.ident;
quote! {
impl HelloMacro for #name {
fn hello() {
println!("Hello from {}!", stringify!(#name));
}
}
}.into()
}
Debugging
cargo expand # Expand all macros
cargo expand main # Expand specific
Troubleshooting
| Problem | Solution |
|---|
| Hygiene issues | Use $crate:: |
| Order matters | Define before use |
Resources
