| 3 | use syn::{Data, DeriveInput, Error}; |
| 4 | |
| 5 | pub(crate) fn state(input: DeriveInput) -> Result<TokenStream, Error> { |
| 6 | let ty_ident = &input.ident; |
| 7 | let _generics = &input.generics; |
| 8 | |
| 9 | let Data::Struct(ref ty) = input.data else { |
| 10 | return Err(Error::new(ty_ident.span(), "expect Struct")); |
| 11 | }; |
| 12 | |
| 13 | let fields = ty |
| 14 | .fields |
| 15 | .iter() |
| 16 | .enumerate() |
| 17 | .filter(|(_, field)| { |
| 18 | field.attrs.iter().any(|attr| { |
| 19 | attr.path() |
| 20 | .segments |
| 21 | .first() |
| 22 | .filter(|seg| seg.ident.to_string().as_str() == "borrow") |
| 23 | .is_some() |
| 24 | }) |
| 25 | }) |
| 26 | .map(|(_, field)| { |
| 27 | let ident = field.ident.as_ref().unwrap(); |
| 28 | let ty = &field.ty; |
| 29 | |
| 30 | quote! { |
| 31 | impl ::xitca_web::handler::state::BorrowState<#ty> for #ty_ident { |
| 32 | fn borrow(&self) -> &#ty { |
| 33 | &self.#ident |
| 34 | } |
| 35 | } |
| 36 | } |
| 37 | }); |
| 38 | |
| 39 | Ok(quote! { #(#fields)* }.into()) |
| 40 | } |