Unable to pass a $:literal from one macro to another

[dtolnay]

I would expect the following program to print right. Instead it prints wrong.

#![feature(macro_literal_matcher)]

macro_rules! a {
    ($i:literal) => { "right" };
    ($i:tt) => { "wrong" };
}

macro_rules! b {
    ($i:literal) => { a!($i) };
}

fn main() {
    println!(b!(0));
}

Originally reported by @jendrikw in #35625 (comment).

[0e4ef622]

Is any work being done on this? I found something that could help.

syntax::ext::tt::macro_parser: may_begin_with("literal", Interpolated((NtLiteral(..), None))) = false

[kennytm]

@0e4ef622 you're welcome to submit a PR 😊. Just remember to add a test case in src/test/run-pass.