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diesel_derives/
from_sql_row.rs

1use proc_macro2::TokenStream;
2use quote::quote;
3use syn::DeriveInput;
4use syn::Result;
5use syn::parse_quote;
6
7use crate::model::Model;
8use crate::util::{ty_for_foreign_derive, wrap_in_dummy_mod};
9
10pub fn derive(item: DeriveInput) -> Result<TokenStream> {
11    let model = Model::from_item(&item, true, false)?;
12    let struct_ty = ty_for_foreign_derive(&item, &model)?;
13    Ok(wrap_in_dummy_mod(derive_inner(struct_ty, item.generics)?))
14}
15
16pub fn derive_inner(struct_ty: syn::Type, mut generics: syn::Generics) -> Result<TokenStream> {
17    {
18        generics.params.push(::syn::__private::parse_quote({
        let mut _s = ::quote::__private::TokenStream::new();
        ::quote::__private::push_ident(&mut _s, "__DB");
        _s
    })parse_quote!(__DB));
19        generics.params.push(::syn::__private::parse_quote({
        let mut _s = ::quote::__private::TokenStream::new();
        ::quote::__private::push_ident(&mut _s, "__ST");
        _s
    })parse_quote!(__ST));
20        let where_clause = generics.make_where_clause();
21        where_clause
22            .predicates
23            .push(::syn::__private::parse_quote({
        let mut _s = ::quote::__private::TokenStream::new();
        ::quote::__private::push_ident(&mut _s, "__DB");
        ::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, "backend");
        ::quote::__private::push_colon2(&mut _s);
        ::quote::__private::push_ident(&mut _s, "Backend");
        _s
    })parse_quote!(__DB: diesel::backend::Backend));
24        where_clause
25            .predicates
26            .push(::syn::__private::parse_quote({
        let mut _s = ::quote::__private::TokenStream::new();
        ::quote::__private::push_ident(&mut _s, "__ST");
        ::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, "sql_types");
        ::quote::__private::push_colon2(&mut _s);
        ::quote::__private::push_ident(&mut _s, "SingleValue");
        _s
    })parse_quote!(__ST: diesel::sql_types::SingleValue));
27        where_clause
28            .predicates
29            .push(::syn::__private::parse_quote({
        let mut _s = ::quote::__private::TokenStream::new();
        ::quote::__private::push_ident(&mut _s, "Self");
        ::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, "deserialize");
        ::quote::__private::push_colon2(&mut _s);
        ::quote::__private::push_ident(&mut _s, "FromSql");
        ::quote::__private::push_lt(&mut _s);
        ::quote::__private::push_ident(&mut _s, "__ST");
        ::quote::__private::push_comma(&mut _s);
        ::quote::__private::push_ident(&mut _s, "__DB");
        ::quote::__private::push_gt(&mut _s);
        _s
    })parse_quote!(Self: diesel::deserialize::FromSql<__ST, __DB>));
30    }
31    let (impl_generics, _, where_clause) = generics.split_for_impl();
32    let implementation = {
    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, "deserialize");
    ::quote::__private::push_colon2(&mut _s);
    ::quote::__private::push_ident(&mut _s, "Queryable");
    ::quote::__private::push_lt(&mut _s);
    ::quote::__private::push_ident(&mut _s, "__ST");
    ::quote::__private::push_comma(&mut _s);
    ::quote::__private::push_ident(&mut _s, "__DB");
    ::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, "Row");
            ::quote::__private::push_eq(&mut _s);
            ::quote::__private::push_ident(&mut _s, "Self");
            ::quote::__private::push_semi(&mut _s);
            ::quote::__private::push_ident(&mut _s, "fn");
            ::quote::__private::push_ident(&mut _s, "build");
            ::quote::__private::push_group(&mut _s,
                ::quote::__private::Delimiter::Parenthesis,
                {
                    let mut _s = ::quote::__private::TokenStream::new();
                    ::quote::__private::push_ident(&mut _s, "row");
                    ::quote::__private::push_colon(&mut _s);
                    ::quote::__private::push_ident(&mut _s, "Self");
                    _s
                });
            ::quote::__private::push_rarrow(&mut _s);
            ::quote::__private::push_ident(&mut _s, "diesel");
            ::quote::__private::push_colon2(&mut _s);
            ::quote::__private::push_ident(&mut _s, "deserialize");
            ::quote::__private::push_colon2(&mut _s);
            ::quote::__private::push_ident(&mut _s, "Result");
            ::quote::__private::push_lt(&mut _s);
            ::quote::__private::push_ident(&mut _s, "Self");
            ::quote::__private::push_gt(&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, "diesel");
                    ::quote::__private::push_colon2(&mut _s);
                    ::quote::__private::push_ident(&mut _s, "deserialize");
                    ::quote::__private::push_colon2(&mut _s);
                    ::quote::__private::push_ident(&mut _s, "Result");
                    ::quote::__private::push_colon2(&mut _s);
                    ::quote::__private::push_ident(&mut _s, "Ok");
                    ::quote::__private::push_group(&mut _s,
                        ::quote::__private::Delimiter::Parenthesis,
                        {
                            let mut _s = ::quote::__private::TokenStream::new();
                            ::quote::__private::push_ident(&mut _s, "row");
                            _s
                        });
                    _s
                });
            _s
        });
    _s
}quote! {
33        // Need to put __ST and __DB after lifetimes but before const params
34        impl #impl_generics diesel::deserialize::Queryable<__ST, __DB> for #struct_ty
35        #where_clause
36        {
37            type Row = Self;
38
39            fn build(row: Self) -> diesel::deserialize::Result<Self> {
40                diesel::deserialize::Result::Ok(row)
41            }
42        }
43    };
44    Ok(implementation)
45}