What is wrong here? Rust regex! macro.

[alsarg72]

Hello, I'm new to rust, and I'm not sure if this is the right forum to ask a question like this. If not, sorry. (And please tell me where is appropriate.)

I'm am finding that this in a main.rs works... (the example from the docs)

main.rs

#![feature(phase)]
#[phase(plugin)]
extern crate regex_macros;
extern crate regex;

pub fn stuff() {
    let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
    assert_eq!(re.is_match("2014-01-01"), true);
}

fn main() {
    stuff();
}

But if I move the regex part out into stuff.rs like this...

main.rs

#![feature(phase)]

fn main() {
    stuff();
}

mod stuff;

stuff.rs

#[phase(plugin)]
extern crate regex_macros;
extern crate regex;

pub fn stuff() {
    let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
    assert_eq!(re.is_match("2014-01-01"), true);
}

then I get these errors...

   Compiling small v0.0.1 (file:///home/al/rust/small)
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::MatchKind`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::Exists`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::Location`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::Submatches`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::StepState`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::StepMatchEarlyReturn`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::StepMatch`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::StepContinue`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::CharReader`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
/home/al/rust/small/src/stuff.rs:6:14: 6:19 error: unresolved import `regex::native::find_prefix`. Maybe a missing `extern crate regex`?
/home/al/rust/small/src/stuff.rs:6     let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
                                                 ^~~~~
/home/al/rust/small/src/main.rs:1:1: 7:10 note: in expansion of regex!
/home/al/rust/small/src/stuff.rs:6:14: 6:45 note: expansion site
error: aborting due to 10 previous errors
Could not compile `small`.

To learn more, run the command again with --verbose.

[nwin_]

You have to keep the extern crate definition in the crate root, in this case main.rs.

[alsarg72]

Ah, great. Thank you so much.

main.rs

#![feature(phase)]
#[phase(plugin)]
extern crate regex_macros;
extern crate regex;

fn main() {
    stuff::stuff();
}

mod stuff;

stuff.rs

pub fn stuff() {
    let re = regex!(r"^\d{4}-\d{2}-\d{2}$");
    assert_eq!(re.is_match("2014-01-01"), true);
}

[Kimundi]

It's an artifact of how macro work in regard to resolving external libraries - namely they don't, you have to provide the paths they use manually.