libmotiva-macros 0.1.0

Macros used by the libmotiva crate
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

use proc_macro::TokenStream;
use quote::quote;

#[derive(deluxe::ParseMetaItem)]
#[deluxe(attributes(scoring_feature))]
struct FeatureAttributes(syn::Ident, #[deluxe(flatten)] FeatureNamedAttributes);

#[derive(deluxe::ParseMetaItem)]
struct FeatureNamedAttributes {
  name: String,
}

#[proc_macro_attribute]
pub fn scoring_feature(attrs: TokenStream, input: TokenStream) -> TokenStream {
  let FeatureAttributes(ident, FeatureNamedAttributes { name }) = deluxe::parse2::<FeatureAttributes>(attrs.into()).unwrap();
  let input = proc_macro2::TokenStream::from(input);

  quote! {
      pub struct #ident;

      impl<'e> Feature<'e> for #ident {
        fn name(&self) -> &'static str {
            #name
        }

        #[tracing::instrument(level = "trace", name = #name, skip_all, fields(entity_id = rhs.id))]
        #input
      }
  }
  .into()
}