Woah, this is unexpected behavior. I've slimmed down this error to:
lib.rs:
```
extern crate serialize;
struct Foo;
impl <D: ::serialize::Decoder<E>, E> ::serialize::Decodable<D, E> for Foo {
fn decode(_d: &mut D) -> Result<Foo, E> {
fail!()
}
}
```
main.rs:
```
mod lib;
fn main() {}
```
Which errors with:
```
lib.rs:5:10: 5:19 error: failed to resolve. Did you mean `self::serialize`?
lib.rs:5 impl <D: ::serialize::Decoder<E>, E> ::serialize::Decodable<D, E>
for Foo {
^~~~~~~~~
lib.rs:5:10: 5:33 error: attempt to bound type parameter with a nonexistent
trait `serialize::Decoder`
lib.rs:5 impl <D: ::serialize::Decoder<E>, E> ::serialize::Decodable<D, E>
for Foo {
^~~~~~~~~~~~~~~~~~~~~~~
lib.rs:5:38: 5:47 error: failed to resolve. Did you mean `self::serialize`?
lib.rs:5 impl <D: ::serialize::Decoder<E>, E> ::serialize::Decodable<D, E>
for Foo {
^~~~~~~~~
lib.rs:5:38: 5:66 error: attempt to implement a nonexistent trait
`serialize::Decodable`
lib.rs:5 impl <D: ::serialize::Decoder<E>, E> ::serialize::Decodable<D, E>
for Foo {
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to 4 previous errors
```
However, if instead we use a relative path to `serialize::Decoder` and etc,
it works:
```
extern crate serialize;
struct Foo;
impl <D: serialize::Decoder<E>, E> serialize::Decodable<D, E> for Foo {
fn decode(_d: &mut D) -> Result<Foo, E> {
fail!()
}
}
```
It also works if we move the `extern crate serialize` into `main.rs`. Since
almost everyone puts the `extern crate` in the lib.rs/main.rs of a project,
we tend not to run into this. I thought this used to work. Has anything
recently changed in name resolution that would have changed how how `extern
crate` works with submodules?
On Fri, Sep 5, 2014 at 8:41 AM, Oldřich Vetešník <oldrich.vetes...@gmail.com
> wrote:
> Hello all,
>
> I’m having some trouble when using external crates in a module. For
> example the following code won’t compile.
> But if I put everything in main.rs it will compile.
> (Note: the code is also here
> https://gist.github.com/ollie/90e266f4cbfcad21501d if it gets mangled
> along the way.)
>
> main.rs:
>
> use lib::decode_json_file;
>
> mod lib;
>
> fn main() {
> decode_json_file();
> }
>
> lib.rs:
>
> extern crate serialize;
>
> use self::serialize::json;
> // This has no effect:
> // use self::serialize::{Decodable, Decoder};
>
> #[deriving(Show, Decodable)]
> struct Foo {
> foo: u8,
> }
>
> pub fn decode_json_file() {
> let raw_json = "{ \"foo\": 1 }";
>
> let foo: Foo = json::decode(raw_json).unwrap();
>
> println!("{}", foo);
> }
>
> When I run rustc main.rs, it prints this:
>
> lib.rs:7:18: 7:27 error: failed to resolve. Did you mean
> `self::serialize`?
> lib.rs:7 #[deriving(Show, Decodable)]
> ^~~~~~~~~
> note: in expansion of #[deriving]
> lib.rs:7:1: 7:29 note: expansion site
> lib.rs:7:18: 7:27 error: attempt to bound type parameter with a
> nonexistent trait `serialize::Decoder`
> lib.rs:7 #[deriving(Show, Decodable)]
> ^~~~~~~~~
> note: in expansion of #[deriving]
> lib.rs:7:1: 7:29 note: expansion site
> lib.rs:7:18: 7:27 error: failed to resolve. Did you mean
> `self::serialize`?
> lib.rs:7 #[deriving(Show, Decodable)]
> ^~~~~~~~~
> note: in expansion of #[deriving]
> lib.rs:7:1: 7:29 note: expansion site
> lib.rs:7:18: 7:27 error: attempt to implement a nonexistent trait
> `serialize::Decodable`
> lib.rs:7 #[deriving(Show, Decodable)]
> ^~~~~~~~~
> note: in expansion of #[deriving]
> lib.rs:7:1: 7:29 note: expansion site
> lib.rs:7:18: 7:27 error: failed to resolve. Did you mean
> `self::serialize::Decodable`?
> lib.rs:7 #[deriving(Show, Decodable)]
> ^~~~~~~~~
> note: in expansion of #[deriving]
> lib.rs:7:1: 7:29 note: expansion site
> lib.rs:7:18: 7:27 error: unresolved name `serialize::Decodable::decode`.
> lib.rs:7 #[deriving(Show, Decodable)]
> ^~~~~~~~~
> note: in expansion of #[deriving]
> lib.rs:7:1: 7:29 note: expansion site
> error: aborting due to 6 previous errors
>
> Am I doing something wrong?
>
> Thank you and have a nice day,
> Ollie
>
> _______________________________________________
> Rust-dev mailing list
> Rust-dev@mozilla.org
> https://mail.mozilla.org/listinfo/rust-dev
>
>
_______________________________________________
Rust-dev mailing list
Rust-dev@mozilla.org
https://mail.mozilla.org/listinfo/rust-dev
