Keep SDK annotated functions in scope

[fibonacci1729]

No description provided.

[fibonacci1729]

Closes #1498

[rylev]

Is the self annotation necessary? I'm not sure why it would be

[lann]

It lets you name your function req.

[rylev]

Ah I didn't think about local variables... 👍

[lann]

Really we should probably be even more careful with our item paths in here with e.g. ::spin_http

[fibonacci1729]

::spin_http won't work; as of rust 2018 paths prefixed with :: must be followed by the name of a crate. We could however say crate::spin_http to prevent a collision with a dependency named spin_http.

ref: https://doc.rust-lang.org/reference/paths.html#path-qualifiers

[fibonacci1729]

@rylev great point; the dunder possibility slipped my brain and i think that is a better choice in this case.

[fibonacci1729]

Unfortunately, it doesn't seem like the standalone option is surfaced in the version of the wit-bindgen macro we are using however alternatively we could do something like:

mod __spin_http {
  wit_bindgen_rust::export!({src["spin_http"]: #HTTP_COMPONENT_WIT});
  pub use spin_http::*;
}

struct SpinHttp;

impl __spin_http::SpinHttp for SpinHttp {
  ...
}

Does this make sense?

[fibonacci1729]

Errr actually i am remembering why this won't work.

The code wit-bindgen generates expects a type SpinHttp in the namespace outside of the generated module, i.e. (from the generated module):

...
let result = <super::SpinHttp as SpinHttp>::handle_http_request

The SDK is currently structured the way it is because the version of wit-bindgen we are using dictates a certain module structure. However, i still think crate::..., albeit less idiomatic, mitigates any collision.

[rylev]

crate:: assumes that the generated code is at the top of the crate. This would prevent using the macro anywhere but at the top of the crate namespace.

[fibonacci1729]

Ahh yeah good catch.

I think this will work:

quote!(
  #func

  mod __spin_http {
    wit_bindgen_rust::export!({src["spin_http"]: #HTTP_COMPONENT_WIT});

    struct SpinHttp;

    impl self::spin_http::SpinHttp for SpinHttp {
      ...
    }
  }
)