use darling::ToTokens;
use syn::spanned::Spanned;
#[derive(Debug)]
pub struct ProviderDef {
pub index: usize,
pub attr_span: proc_macro2::Span,
}
mod keyword {
syn::custom_keyword!(Provider);
}
impl ProviderDef {
pub fn try_from(
attr_span: proc_macro2::Span,
index: usize,
item: &mut syn::Item,
) -> syn::Result<Self> {
let item = if let syn::Item::Struct(item) = item {
item
} else {
let msg = "Invalid provider::provider, expected struct";
return Err(syn::Error::new(item.span(), msg))
};
if !matches!(item.vis, syn::Visibility::Public(_)) {
let msg = "Invalid provider::provider, struct must be public";
return Err(syn::Error::new(item.span(), msg))
}
syn::parse2::<keyword::Provider>(item.ident.to_token_stream())?;
Ok(Self { index, attr_span })
}
}