use proc_macro::TokenStream;
use quote::quote;
use syn::{Attribute, DeriveInput, Ident, parse_macro_input};
fn parse_group_attribute(attrs: &[Attribute]) -> Option<Ident> {
for attr in attrs {
if attr.path().is_ident("group")
&& let Ok(meta) = attr.parse_args::<syn::Meta>()
&& let syn::Meta::Path(path) = meta
&& let Some(segment) = path.segments.last()
{
return Some(segment.ident.clone());
}
}
None
}
pub fn derive_groupped(input: TokenStream) -> TokenStream {
let input = parse_macro_input!(input as DeriveInput);
let struct_name = input.ident;
let group_ident: proc_macro2::TokenStream = parse_group_attribute(&input.attrs)
.map(|ident| quote! { #ident })
.unwrap_or_else(crate::default_program_path);
let any_output_convert_impls = proc_macro2::TokenStream::from(build_any_output_convert_impls(
struct_name.clone(),
group_ident.clone(),
));
let expanded = quote! {
::mingling::macros::register_type!(#struct_name);
impl ::mingling::Groupped<#group_ident> for #struct_name {
fn member_id() -> #group_ident {
#group_ident::#struct_name
}
}
#any_output_convert_impls
};
expanded.into()
}
#[cfg(feature = "general_renderer")]
pub fn derive_groupped_serialize(input: TokenStream) -> TokenStream {
let input_parsed = parse_macro_input!(input as DeriveInput);
let struct_name = input_parsed.ident.clone();
let group_ident: proc_macro2::TokenStream = parse_group_attribute(&input_parsed.attrs)
.map(|ident| quote! { #ident })
.unwrap_or_else(crate::default_program_path);
let any_output_convert_impls = proc_macro2::TokenStream::from(build_any_output_convert_impls(
struct_name.clone(),
group_ident.clone(),
));
let expanded = quote! {
#[derive(serde::Serialize)]
#input_parsed
::mingling::macros::register_type!(#struct_name);
impl ::mingling::Groupped<#group_ident> for #struct_name {
fn member_id() -> #group_ident {
#group_ident::#struct_name
}
}
#any_output_convert_impls
};
expanded.into()
}
fn build_any_output_convert_impls(
struct_name: Ident,
group_ident: proc_macro2::TokenStream,
) -> TokenStream {
quote! {
impl ::std::convert::Into<::mingling::AnyOutput<#group_ident>> for #struct_name {
fn into(self) -> ::mingling::AnyOutput<#group_ident> {
::mingling::AnyOutput::new(self)
}
}
impl ::std::convert::Into<::mingling::ChainProcess<#group_ident>> for #struct_name {
fn into(self) -> ::mingling::ChainProcess<#group_ident> {
::mingling::AnyOutput::new(self).route_chain()
}
}
impl #struct_name {
pub fn to_chain(self) -> ::mingling::ChainProcess<#group_ident> {
::mingling::AnyOutput::new(self).route_chain()
}
pub fn to_render(self) -> ::mingling::ChainProcess<#group_ident> {
::mingling::AnyOutput::new(self).route_renderer()
}
}
}
.into()
}