Attribute Macro arret_rfi_derive::rust_fun

#[rust_fun]

Annotates a Rust function to be exported via arret_runtime::define_rust_module!

This takes a single metadata string containing the full Arret type of the function. This is used to express concepts in Arret that don’t exist in Rust. These include rest arguments and function purity.

The annotated Rust function can optionally take a arret_runtime::task::Task as its first parameter. An attempt will be made to encode the types of the remaining parameters but only certain primitive types and arret_runtime::boxed values are allowed.