1use proc_macro::TokenStream;
2use quote::quote;
3use syn::{parse_macro_input, ItemStruct};
4
5#[proc_macro_attribute]
6pub fn game(_attr: TokenStream, item: TokenStream) -> TokenStream {
7 let input = parse_macro_input!(item as ItemStruct);
8 let struct_ident = input.ident.clone();
9
10 let expanded = quote! {
11 #input
12
13 #[no_mangle]
14 #[cfg(turbo_hot_reload)]
15 pub unsafe extern "C" fn run() {
16 use turbo::sys;
17
18 let mut state = match sys::load() {
19 Ok(bytes) => <#struct_ident>::try_from_slice(&bytes).unwrap_or_else(|_| #struct_ident::new()),
20 Err(_) => #struct_ident::new(),
21 };
22
23 state.update();
24
25 if let Ok(bytes) = state.try_to_vec() {
26 let _ = sys::save(&bytes);
27 }
28 }
29
30 #[no_mangle]
31 #[cfg(not(turbo_hot_reload))]
32 pub unsafe extern "C" fn run() {
33 static mut GAME_STATE: Option<#struct_ident> = None;
34
35 let mut state = GAME_STATE.take().unwrap_or_else(#struct_ident::new);
36
37 state.update();
38
39 GAME_STATE = Some(state);
40 }
41 };
42
43 TokenStream::from(expanded)
44}