diesel_derives/
valid_grouping.rs1use proc_macro2::TokenStream;
2use quote::quote;
3use syn::parse_quote;
4use syn::DeriveInput;
5use syn::Result;
6
7use crate::model::Model;
8use crate::util::{ty_for_foreign_derive, wrap_in_dummy_mod};
9
10pub fn derive(mut item: DeriveInput) -> Result<TokenStream> {
11 let model = Model::from_item(&item, true, false)?;
12 let struct_ty = ty_for_foreign_derive(&item, &model)?;
13
14 let type_params = item
15 .generics
16 .type_params()
17 .map(|param| param.ident.clone())
18 .collect::<Vec<_>>();
19
20 for type_param in type_params {
21 let where_clause = item.generics.make_where_clause();
22 where_clause
23 .predicates
24 .push(::syn::__private::parse_quote({
let mut _s = ::quote::__private::TokenStream::new();
::quote::ToTokens::to_tokens(&type_param, &mut _s);
::quote::__private::push_colon(&mut _s);
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "ValidGrouping");
::quote::__private::push_lt(&mut _s);
::quote::__private::push_ident(&mut _s, "__GroupByClause");
::quote::__private::push_gt(&mut _s);
_s
})parse_quote!(#type_param: diesel::expression::ValidGrouping<__GroupByClause>));
25 }
26
27 if model.aggregate {
28 item.generics.params.push(::syn::__private::parse_quote({
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_ident(&mut _s, "__GroupByClause");
_s
})parse_quote!(__GroupByClause));
29 let (impl_generics, _, where_clause) = item.generics.split_for_impl();
30
31 Ok(wrap_in_dummy_mod({
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_ident(&mut _s, "impl");
::quote::ToTokens::to_tokens(&impl_generics, &mut _s);
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "ValidGrouping");
::quote::__private::push_lt(&mut _s);
::quote::__private::push_ident(&mut _s, "__GroupByClause");
::quote::__private::push_gt(&mut _s);
::quote::__private::push_ident(&mut _s, "for");
::quote::ToTokens::to_tokens(&struct_ty, &mut _s);
::quote::ToTokens::to_tokens(&where_clause, &mut _s);
::quote::__private::push_group(&mut _s,
::quote::__private::Delimiter::Brace,
{
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_ident(&mut _s, "type");
::quote::__private::push_ident(&mut _s, "IsAggregate");
::quote::__private::push_eq(&mut _s);
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "is_aggregate");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "Yes");
::quote::__private::push_semi(&mut _s);
_s
});
_s
}quote! {
32 impl #impl_generics diesel::expression::ValidGrouping<__GroupByClause> for #struct_ty
33 #where_clause
34 {
35 type IsAggregate = diesel::expression::is_aggregate::Yes;
36 }
37 }))
38 } else {
39 let mut aggregates = item
40 .generics
41 .type_params()
42 .map(
43 |t| {
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_lt(&mut _s);
::quote::ToTokens::to_tokens(&t, &mut _s);
::quote::__private::push_ident(&mut _s, "as");
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "ValidGrouping");
::quote::__private::push_lt(&mut _s);
::quote::__private::push_ident(&mut _s, "__GroupByClause");
::quote::__private::push_shr(&mut _s);
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "IsAggregate");
_s
}quote!(<#t as diesel::expression::ValidGrouping<__GroupByClause>>::IsAggregate),
44 )
45 .collect::<Vec<_>>()
46 .into_iter();
47
48 let is_aggregate = aggregates
49 .next()
50 .map(|first| {
51 let where_clause = item.generics.make_where_clause();
52 aggregates.fold(first, |left, right| {
53 where_clause.predicates.push(::syn::__private::parse_quote({
let mut _s = ::quote::__private::TokenStream::new();
::quote::ToTokens::to_tokens(&left, &mut _s);
::quote::__private::push_colon(&mut _s);
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "MixedAggregates");
::quote::__private::push_lt(&mut _s);
::quote::ToTokens::to_tokens(&right, &mut _s);
::quote::__private::push_gt(&mut _s);
_s
})parse_quote!(
54 #left: diesel::expression::MixedAggregates<#right>
55 ));
56 {
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_lt(&mut _s);
::quote::ToTokens::to_tokens(&left, &mut _s);
::quote::__private::push_ident(&mut _s, "as");
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "MixedAggregates");
::quote::__private::push_lt(&mut _s);
::quote::ToTokens::to_tokens(&right, &mut _s);
::quote::__private::push_shr(&mut _s);
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "Output");
_s
}quote!(<#left as diesel::expression::MixedAggregates<#right>>::Output)
57 })
58 })
59 .unwrap_or_else(|| {
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "is_aggregate");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "Never");
_s
}quote!(diesel::expression::is_aggregate::Never));
60
61 item.generics.params.push(::syn::__private::parse_quote({
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_ident(&mut _s, "__GroupByClause");
_s
})parse_quote!(__GroupByClause));
62 let (impl_generics, _, where_clause) = item.generics.split_for_impl();
63
64 Ok(wrap_in_dummy_mod({
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_ident(&mut _s, "impl");
::quote::ToTokens::to_tokens(&impl_generics, &mut _s);
::quote::__private::push_ident(&mut _s, "diesel");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "expression");
::quote::__private::push_colon2(&mut _s);
::quote::__private::push_ident(&mut _s, "ValidGrouping");
::quote::__private::push_lt(&mut _s);
::quote::__private::push_ident(&mut _s, "__GroupByClause");
::quote::__private::push_gt(&mut _s);
::quote::__private::push_ident(&mut _s, "for");
::quote::ToTokens::to_tokens(&struct_ty, &mut _s);
::quote::ToTokens::to_tokens(&where_clause, &mut _s);
::quote::__private::push_group(&mut _s,
::quote::__private::Delimiter::Brace,
{
let mut _s = ::quote::__private::TokenStream::new();
::quote::__private::push_ident(&mut _s, "type");
::quote::__private::push_ident(&mut _s, "IsAggregate");
::quote::__private::push_eq(&mut _s);
::quote::ToTokens::to_tokens(&is_aggregate, &mut _s);
::quote::__private::push_semi(&mut _s);
_s
});
_s
}quote! {
65
66 impl #impl_generics diesel::expression::ValidGrouping<__GroupByClause> for #struct_ty
67 #where_clause
68 {
69 type IsAggregate = #is_aggregate;
70 }
71 }))
72 }
73}