The repository demonstrates the usage of cairo plugin system. It contains the plugin which for each function annotated with hello attribute prints Hello, <function-name>!.
Setup the cairo environment with the asdf install command.
To use the plugin in your project annotate a function with hello attribute:
#[hello]
fn multiply(a: u8, b: u8) -> u8 {
a * b
}
An example project is located in example directory.
- cd into project directory:
cd example/
- Run scarb with the hello-cairo-plugin:
scarb cairo-run
- You should see the output:
Running examples
[DEBUG] 0x48656c6c6f2c206d61696e21 ('Hello, main!')
[DEBUG] 0x48656c6c6f2c2061646421 ('Hello, add!')
[DEBUG] 0x48656c6c6f2c206d756c7469706c7921 ('Hello, multiply!')
[DEBUG] 0x48656c6c6f2c20666f6f21 ('Hello, foo!')
Run completed successfully, returning []
The repository shows the implementation of cairo plugin with macros. For the implementation of macros see src/lib.rs. The file illustrates two approaches to developing attribute macros:
- hello macro using native cairo parser
- hello_regex macro implementing the same functionality using regex
It is recommended especially for complex macros to use the native cairo parser as regexes are often error prone and have their limitations. They are lightweight however and may be enough for some macros.
For more see scarb's documentation on procedural macros.