How do I write a wrapper for a macro without repeating the rules?

Question

I am trying to make a wrapper for a macro. The trouble is that I don't want to repeat the same rules in both macro. Is there a way to do that?

Here is what I tried:

macro_rules! inner {
    ($test:ident) => { stringify!($test) };
    ($test:ident.run()) => { format!("{}.run()", stringify!($test)) };
}

macro_rules! outer {
    ($expression:expr) => {
        println!("{}", inner!($expression));
    }
}

fn main() {
    println!("{}", inner!(test));
    println!("{}", inner!(test.run()));
    outer!(test);
    outer!(test.run());
}

but I get the following error:

src/main.rs:8:31: 8:42 error: expected ident, found test
src/main.rs:8         println!("{}", inner!($expression));
                                            ^~~~~~~~~~~

If I change the outer macro for this, the code compile:

macro_rules! outer {
    ($expression:expr) => {
        println!("{}", stringify!($expression));
    }
}

What am I doing wrong?

Answer 1

I had some success with the $($stuff: expr),+ syntax.

macro_rules! println {
    ( $($stuff: expr),+) => {
    avr_device::interrupt::free(|cs| {
    uwriteln!(unsafe { &SERIAL_STATIC}.borrow(cs).borrow_mut().as_mut().unwrap(),
    $($stuff),+)
    })
    }
}