71 lines
2.3 KiB
Rust
71 lines
2.3 KiB
Rust
use proc_macro::TokenStream;
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use quote::quote;
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use syn::{parse_macro_input, parse_quote, DeriveInput};
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pub fn derive_component(input: TokenStream) -> TokenStream {
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let mut ast = parse_macro_input!(input as DeriveInput);
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if !ast
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.generics
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.params
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.iter()
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.any(|param| matches!(param, syn::GenericParam::Type(_)))
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{
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ast.generics.params.push(parse_quote! {
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V: 'static
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});
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}
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let name = &ast.ident;
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let generics = &ast.generics;
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let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
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let specified_view_type = ast
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.attrs
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.iter()
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.find(|attr| attr.path.is_ident("component"))
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.and_then(|attr| {
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if let Ok(syn::Meta::List(meta_list)) = attr.parse_meta() {
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meta_list.nested.iter().find_map(|nested| {
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if let syn::NestedMeta::Meta(syn::Meta::NameValue(nv)) = nested {
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if nv.path.is_ident("view_type") {
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if let syn::Lit::Str(lit_str) = &nv.lit {
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return Some(
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lit_str
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.parse::<syn::Ident>()
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.expect("Failed to parse view_type"),
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);
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}
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}
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}
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None
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})
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} else {
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None
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}
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});
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let view_type = specified_view_type.unwrap_or_else(|| {
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if let Some(syn::GenericParam::Type(type_param)) = generics.params.first() {
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type_param.ident.clone()
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} else {
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panic!("Expected first type parameter to be a view type");
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}
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});
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let expanded = quote! {
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impl #impl_generics gpui2::Component<#view_type> for #name #ty_generics #where_clause {
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fn render(self) -> gpui2::AnyElement<#view_type> {
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(move |view_state: &mut #view_type, cx: &mut gpui2::ViewContext<'_, '_, #view_type>| self.render(view_state, cx))
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.render()
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}
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}
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};
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if name == "AssistantPanelStory" {
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println!("Expanded tokens: {}", expanded.to_string());
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}
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TokenStream::from(expanded)
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}
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