Generating a Route in a Macro

[jafioti]

Hi,
I would like to generate a route for a function in a macro. For instance, I have a function:

fn hello() {
     println!("Hello");
}

And I would like to generate a route for it:

#[get("/hello")]
fn hello_route() {
     hello()
}

How would I go about doing this? I currently have

#[macro_export]
macro_rules! generate_functions {
    ($vis:vis fn $name:ident($($arg:ident: $arg_type:ty)*) $code:block) => {
        ::paste::paste! {
            $vis fn $name($($arg: $arg_type)*) $code

            #[get("/" $name)]
            $vis fn [<$name _route>]($($arg: $arg_type)*) {
                $name($($arg)*)
            }
        }
    };
}

But that doesn't work because it doesn't properly set the route path in the #[get()] macro.

[the10thWiz]

You probably want to use the concat! macro to combine the path into a single literal.

#[get(concat!("/", $name)]

That being said, why do you want to do this? Rocket routes are still functions you can call, so

#[get("/hello")]
fn hello() -> &str {
  "Hello world!"
}

fn other() {
  // This is perfectly valid
  hello();
}

Rocket already internally generates a wrapper that just calls your function.

[jafioti]

I ended up having to use a proc macro. I packaged it up in a crate here: https://github.com/Sidekick-AI/retrofit