diff options
Diffstat (limited to 'mingling_macros/src/renderer.rs')
| -rw-r--r-- | mingling_macros/src/renderer.rs | 67 |
1 files changed, 16 insertions, 51 deletions
diff --git a/mingling_macros/src/renderer.rs b/mingling_macros/src/renderer.rs index 880c50f..d124ec9 100644 --- a/mingling_macros/src/renderer.rs +++ b/mingling_macros/src/renderer.rs @@ -1,22 +1,15 @@ use proc_macro::TokenStream; use quote::{ToTokens, quote}; use syn::spanned::Spanned; -use syn::{ItemFn, ReturnType, Signature, Type, TypePath, parse_macro_input}; +use syn::{ItemFn, ReturnType, Signature, TypePath, parse_macro_input}; use crate::get_global_set; use crate::res_injection::{extract_args_info, generate_immut_resource_bindings}; -/// Extracts and returns the return type from the function signature (or None for `()` / no return type). -fn extract_return_type(sig: &Signature) -> Option<syn::Type> { +/// Extracts the user's return type, returning `None` for no return type. +fn extract_user_return_type(sig: &Signature) -> Option<proc_macro2::TokenStream> { match &sig.output { - ReturnType::Type(_, ty) => { - match &**ty { - // `()` means no custom return type - Type::Tuple(tuple) if tuple.elems.is_empty() => None, - // Any other return type is allowed - custom_ty => Some((*custom_ty).clone()), - } - } + ReturnType::Type(_, ty) => Some(quote! { #ty }), ReturnType::Default => None, } } @@ -44,8 +37,8 @@ pub fn renderer_attr(attr: TokenStream, item: TokenStream) -> TokenStream { Err(e) => return e.to_compile_error().into(), }; - // Validate return type – now returns Some(type) if custom type, None if () - let return_type = extract_return_type(&input_fn.sig); + // Determine the user's return type and whether it needs to be converted to RenderResult + let user_return_type = extract_user_return_type(&input_fn.sig); // Get function body statements let fn_body_stmts: Vec<syn::Stmt> = input_fn.block.stmts.clone(); @@ -76,23 +69,6 @@ pub fn renderer_attr(attr: TokenStream, item: TokenStream) -> TokenStream { let immut_resource_stmts = generate_immut_resource_bindings(resources.iter(), program_type); let mut_resources: Vec<_> = resources.iter().filter(|r| r.is_mut).collect(); - // Determine public return type and the expression to return dummy_r - let (public_return_type, result_return) = if let Some(custom_ty) = &return_type { - // User specified a custom return type (e.g. -> String) - let ret_ty = quote! { #custom_ty }; - let expr = quote! { dummy_r.into() }; - (ret_ty, expr) - } else { - // Return type is () — no custom return type specified - let ret_ty = quote! { () }; - let expr = quote! { - if !dummy_r.is_empty() { - ::std::println!("{}", &*dummy_r); - } - }; - (ret_ty, expr) - }; - let inner_body_with_resources = if has_mut_resources { let mut wrapped = quote! { #(#fn_body_stmts)* }; for res in mut_resources.iter().rev() { @@ -110,8 +86,7 @@ pub fn renderer_attr(attr: TokenStream, item: TokenStream) -> TokenStream { }; // Build the Renderer::render body with resource injection - // Renderer::render returns (), output goes through __renderer_inner_result parameter. - // Resources are injected from the program context here. + // The user's body now directly creates and returns a RenderResult. let render_fn_body = if has_resources { quote! { #(#immut_resource_stmts)* @@ -121,22 +96,10 @@ pub fn renderer_attr(attr: TokenStream, item: TokenStream) -> TokenStream { quote! { #inner_body_with_resources } }; - // Build the original function body - // The original function preserves the user's signature and return type. + // The original function preserves the user's exact signature and body. // Resource parameters are passed directly by the caller, NOT injected from context. - let original_fn_body = { - quote! { - let mut dummy_r = ::mingling::RenderResult::default(); - { - let __renderer_inner_result = &mut dummy_r; - #(#fn_body_stmts)* - } - #result_return - } - }; - - // Keep the original function signature unchanged (same params as user wrote) let original_inputs = input_fn.sig.inputs.clone(); + let original_return_type = user_return_type.clone().unwrap_or(quote! { () }); let expanded = quote! { #(#fn_attrs)* @@ -149,15 +112,17 @@ pub fn renderer_attr(attr: TokenStream, item: TokenStream) -> TokenStream { impl ::mingling::Renderer for #struct_name { type Previous = #previous_type; - fn render(#prev_param: Self::Previous, __renderer_inner_result: &mut ::mingling::RenderResult) { - #render_fn_body + fn render(#prev_param: Self::Previous) -> ::mingling::RenderResult { + let __renderer_result = { #render_fn_body }; + ::std::convert::Into::into(__renderer_result) } } - // Keep the original function for internal use (without r parameter) + // Keep the original function unchanged + #[allow(dead_code)] #(#fn_attrs)* - #vis fn #fn_name(#original_inputs) -> #public_return_type { - #original_fn_body + #vis fn #fn_name(#original_inputs) -> #original_return_type { + #(#fn_body_stmts)* } }; |
