Is there any way to export both declarative macros and procedural macros from a single crate?

help
1

I've created a simple crate, that exports convenient macros for decreasing the amount of duplicate code, it would be nice to export both declarative macros and procedural macros from this crate. I couldn't find the answer on the internet so I came here to ask if it's possible or is there a way around that restriction: error: cannot export macro_rules! macros from a proc-macro crate type currently

2

There's not really any way to get around the fact that proc macros have to be defined in their special own crate type, but a way to accomplish the same effect could be a public facing crate that defines your declarative macros and re-exports the proc-macros.

1 Like
3

I thought about what you said and it really helped me, thank you.

4

how to do?

5

I've basically created an additional crate for the main one, which contains all of the procedural macros, and re-exported it in the main crate like this: pub extern crate your_proc_macros_crate;. And after that you can use main_crate::your_proc_macros_crate::something. Here's an example:

├── Cargo.toml
├── proc-macros-crate
│   ├── Cargo.toml
│   ├── README.md
│   └── src
│       ├── ...
│       └── lib.rs
├── src
│   ├── ...
│   └── lib.rs
└── tests
    ├── Cargo.lock
    ├── Cargo.toml
    └── lib.rs

in tests/lib.rs:
#[cfg(test)]
mod tests {
    ...
    use main_crate::*;
    use main_crate::proc_macros_crate::*;
    ...

Or you can see how it looks like in my noobie repo

6

You can also reexport each macro individually with pub use proc_macro_crate::macro_name;, which can be nice for downstream users so they don't need to know about proc_macro_crate.

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7

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