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Implement #[implicit] to automatically generate fields using the new ImplicitField trait

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Carl Sverre 2024-12-19 11:40:24 -08:00
parent 2bd29821f4
commit 5195f7ccfa
8 changed files with 223 additions and 12 deletions
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19
impl/src/expand.rs
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@ -166,12 +166,14 @@ fn impl_struct(input: Struct) -> TokenStream {
let from_impl = input.from_field().map(|from_field| {
let span = from_field.attrs.from.unwrap().span;
let backtrace_field = input.distinct_backtrace_field();
let implicit_fields = input.implicit_fields();
let from = unoptional_type(from_field.ty);
let source_var = Ident::new("source", span);
let body = from_initializer(from_field, backtrace_field, &source_var);
let body = from_initializer(from_field, backtrace_field, implicit_fields, &source_var);
let from_impl = quote_spanned! {span=>
#[automatically_derived]
impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause {
#[track_caller]
fn from(#source_var: #from) -> Self {
#ty #body
}
@ -432,13 +434,15 @@ fn impl_enum(input: Enum) -> TokenStream {
let from_field = variant.from_field()?;
let span = from_field.attrs.from.unwrap().span;
let backtrace_field = variant.distinct_backtrace_field();
let implicit_fields = variant.implicit_fields();
let variant = &variant.ident;
let from = unoptional_type(from_field.ty);
let source_var = Ident::new("source", span);
let body = from_initializer(from_field, backtrace_field, &source_var);
let body = from_initializer(from_field, backtrace_field, implicit_fields, &source_var);
let from_impl = quote_spanned! {span=>
#[automatically_derived]
impl #impl_generics ::core::convert::From<#from> for #ty #ty_generics #where_clause {
#[track_caller]
fn from(#source_var: #from) -> Self {
#ty::#variant #body
}
@ -505,6 +509,7 @@ fn use_as_display(needs_as_display: bool) -> Option<TokenStream> {
fn from_initializer(
from_field: &Field,
backtrace_field: Option<&Field>,
implicit_fields: Vec<&Field>,
source_var: &Ident,
) -> TokenStream {
let from_member = &from_field.member;
@ -525,7 +530,17 @@ fn from_initializer(
}
}
});
let implicit = implicit_fields
.iter()
.map(|field| {
let member = &field.member;
quote! {
#member: ::thiserror::ImplicitField::generate_with_source(&#source_var),
}
})
.collect::<TokenStream>();
quote!({
#implicit
#from_member: #some_source,
#backtrace
})