microrm-macros 0.5.0

Procedural macro implementations for the microrm crate.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40

use quote::quote;

pub fn derive(tokens: proc_macro::TokenStream) -> proc_macro::TokenStream {
    let input: syn::DeriveInput = syn::parse_macro_input!(tokens);

    let items = if let syn::Data::Struct(syn::DataStruct {
        struct_token: _,
        fields: syn::Fields::Named(fields),
        semi_token: _,
    }) = input.data
    {
        fields
            .named
            .into_iter()
            .map(|f| (f.ident.unwrap(), f.ty))
            .collect::<Vec<_>>()
    } else {
        panic!("Can only derive Schema on data structs with named fields!");
    };

    let item_ident = input.ident;

    let visit_items = items.iter().map(|field| {
        let item_type = &field.1;

        quote! {
            <#item_type as ::microrm::schema::DatabaseItem>::accept_item_visitor(&<#item_type as Default>::default(), v);
        }
    });

    quote! {
        impl ::microrm::schema::DatabaseItem for #item_ident {
            fn accept_item_visitor(&self, v: &mut impl ::microrm::schema::DatabaseItemVisitor) {
                use ::microrm::schema::DatabaseItem;
                #(#visit_items)*
            }
        }
    }
    .into()
}