kairoi-macros 0.2.0

Procedural macros for kairoi 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;
use syn::{parse_macro_input, ItemFn};

#[proc_macro_attribute]
pub fn instrument(_attr: TokenStream, item: TokenStream) -> TokenStream {
    let input_fn = parse_macro_input!(item as ItemFn);

    let vis = &input_fn.vis;
    let sig = &input_fn.sig;
    let block = &input_fn.block;
    let fn_name = &sig.ident;
    let fn_name_str = fn_name.to_string();

    if sig.asyncness.is_none() {
        let msg = "instrument macro can only be used on async functions";
        return syn::Error::new_spanned(sig, msg).to_compile_error().into();
    }

    let output = quote! {
            #vis #sig {
                let span_data = kairoi::Span::default().with_name(#fn_name_str.to_string());
                kairoi::Span::scope(async move |scope| {
                    scope.update(span_data);
                    #block
                }).await
            }
        };

    TokenStream::from(output)
}