proc-macro2

Documentation

A small shim over the proc_macro crate in the compiler intended to multiplex the current stable interface (as of 2017-07-05) and the upcoming richer interface.

The upcoming support has features like:

• Span information on tokens
• No need to go in/out through strings
• Structured input/output

The hope is that libraries ported to proc_macro2 will be trivial to port to the real proc_macro crate once the support on nightly is stabilize.

Usage

This crate by default compiles on the stable version of the compiler. It only uses the stable surface area of the proc_macro crate upstream in the compiler itself. Usage is done via:

toml [dependencies] proc-macro2 = "0.1"

followed by

```rust extern crate procmacro; extern crate procmacro2;

[procmacroderive(MyDerive)]

pub fn myderive(input: procmacro::TokenStream) -> procmacro::TokenStream { let input: procmacro2::TokenStream = input.into();

let output: proc_macro2::TokenStream = {
    /* transform input */
};

output.into()

} ```

If you'd like you can enable the unstable feature in this crate. This will cause it to compile against the unstable and nightly-only features of the proc_macro crate. This in turn requires a nightly compiler. This should help preserve span information, however, coming in from the compiler itself.

You can enable this feature via:

toml [dependencies] proc-macro2 = { version = "0.1", features = ["unstable"] }

License

proc-macro2 is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.

See LICENSE-APACHE, and LICENSE-MIT for details.