39 lines
1.3 KiB
Rust
39 lines
1.3 KiB
Rust
use crate::modules::{get_modules, get_path};
|
|
use proc_macro::TokenStream;
|
|
use quote::quote;
|
|
use syn::{parse_macro_input, Data, DataStruct, DeriveInput, Fields};
|
|
|
|
pub fn derive_from_resources(input: TokenStream) -> TokenStream {
|
|
let ast = parse_macro_input!(input as DeriveInput);
|
|
let fields = match &ast.data {
|
|
Data::Struct(DataStruct {
|
|
fields: Fields::Named(fields),
|
|
..
|
|
}) => &fields.named,
|
|
_ => panic!("expected a struct with named fields"),
|
|
};
|
|
|
|
let modules = get_modules(&ast.attrs);
|
|
let bevy_app_path = get_path(&modules.bevy_app);
|
|
|
|
let field_types = fields.iter().map(|field| &field.ty);
|
|
|
|
let fields = fields.iter().map(|field| field.ident.as_ref().unwrap());
|
|
|
|
let generics = ast.generics;
|
|
let (impl_generics, ty_generics, _where_clause) = generics.split_for_impl();
|
|
|
|
let struct_name = &ast.ident;
|
|
|
|
TokenStream::from(quote! {
|
|
impl #impl_generics #bevy_app_path::FromResources for #struct_name#ty_generics {
|
|
fn from_resources(resources: &Resources) -> Self {
|
|
use #bevy_app_path::FromResources;
|
|
#struct_name {
|
|
#(#fields: <#field_types>::from_resources(resources),)*
|
|
}
|
|
}
|
|
}
|
|
})
|
|
}
|