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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use std::collections::HashSet;
use proc_macro2::TokenStream;
use quote::{format_ident, quote};
use syn::{Data, DataEnum, DataStruct, DeriveInput, Ident, Result};
pub fn expand_derive(input: DeriveInput) -> Result<TokenStream> {
match input.data {
Data::Struct(st) => render_struct(input.ident, st),
Data::Enum(en) => render_enum(input.ident, en),
Data::Union(_) => panic!("#[derive(Node)] is not supported for unions"),
}
}
fn render_struct(ident: Ident, st: DataStruct) -> Result<TokenStream> {
let type_name = ident.to_string();
let members = st.fields.members();
let unique_field_types = st
.fields
.iter()
.map(|f| &f.ty)
.collect::<HashSet<_>>()
.into_iter();
Ok(quote! {
#[automatically_derived]
impl ::uniffi_pipeline::Node for #ident {
fn type_name(&self) -> Option<&'static str> {
Some(#type_name)
}
fn as_any(&self) -> &dyn ::std::any::Any {
self
}
fn to_box_any(self: ::std::boxed::Box<Self>) -> ::std::boxed::Box<dyn ::std::any::Any> {
self
}
fn visit_children<'a>(&'a self, visitor: &mut dyn FnMut(&'a dyn Node)) {
#(
visitor(&self.#members);
)*
}
fn has_descendant_type<N: Node>(visited: &mut ::std::collections::HashSet::<::std::any::TypeId>) -> bool {
use std::any::TypeId;
if TypeId::of::<N>() == TypeId::of::<Self>() {
return true
}
if !visited.insert(TypeId::of::<Self>()) {
return false;
}
#(
if <#unique_field_types as ::uniffi_pipeline::Node>::has_descendant_type::<N>(visited) {
return true
}
)*
false
}
}
})
}
fn render_enum(ident: Ident, en: DataEnum) -> Result<TokenStream> {
let type_name = ident.to_string();
let arms = en.variants.iter().map(|v| {
let vident = &v.ident;
let members = v.fields.members();
let vars = (0..v.fields.len())
.map(|i| format_ident!("var{i}"))
.collect::<Vec<_>>();
quote! {
Self::#vident { #(#members: #vars),* } => {
#(
visitor(#vars);
)*
}
}
});
let unique_field_types = en
.variants
.iter()
.flat_map(|v| v.fields.iter().map(|f| &f.ty))
.collect::<HashSet<_>>()
.into_iter();
Ok(quote! {
#[automatically_derived]
impl ::uniffi_pipeline::Node for #ident {
fn type_name(&self) -> Option<&'static str> {
Some(#type_name)
}
fn as_any(&self) -> &dyn ::std::any::Any {
self
}
fn to_box_any(self: ::std::boxed::Box<Self>) -> ::std::boxed::Box<dyn ::std::any::Any> {
self
}
fn visit_children<'a>(&'a self, visitor: &mut dyn FnMut(&'a dyn Node)) {
match self {
#(
#arms
)*
}
}
fn has_descendant_type<N: Node>(visited: &mut ::std::collections::HashSet::<::std::any::TypeId>) -> bool {
use std::any::TypeId;
if TypeId::of::<N>() == TypeId::of::<Self>() {
return true
}
if !visited.insert(TypeId::of::<Self>()) {
return false;
}
#(
if <#unique_field_types as ::uniffi_pipeline::Node>::has_descendant_type::<N>(visited) {
return true
}
)*
false
}
}
})
}