fusion-core-macros 0.1.0

A data fusion platform with scheduler, ai agent studio and core libraries
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

use proc_macro2::{Span, TokenStream};
use quote::quote;

pub(crate) fn expand_derive(input: syn::DeriveInput) -> syn::Result<TokenStream> {
  let prefix = get_prefix(&input)?;
  let ident = input.ident;

  let output = quote! {
      impl ::fusion_core::configuration::Configurable for #ident {
        fn config_prefix() -> &'static str {
          #prefix
        }
      }
  };

  Ok(output)
}

fn get_prefix(input: &syn::DeriveInput) -> syn::Result<syn::LitStr> {
  let attr = input.attrs.iter().filter(|attr| attr.path().is_ident("config_prefix")).next_back();

  if let Some(syn::Attribute { meta: syn::Meta::NameValue(name_value), .. }) = attr
    && name_value.path.is_ident("config_prefix")
    && let syn::Expr::Lit(syn::ExprLit { lit: syn::Lit::Str(lit), .. }) = &name_value.value
  {
    return Ok(lit.clone());
  }

  Err(syn::Error::new(Span::call_site(), "missing attribute for Configuration, expected: #[config_prefix=\"prefix\"]"))
}