doku-derive 0.21.2

A framework for building documentation (internal macro)
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
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77

use super::*;

pub fn expand_enum(
    input: &syn::DeriveInput,
    data: &syn::DataEnum,
) -> Result<TokenStream2> {
    let syn::DeriveInput { ident, .. } = input;
    let doku = attrs::DokuContainer::from_ast(&input.attrs)?;
    let serde = attrs::SerdeContainer::from_ast(&input.attrs)?;

    let ty_kind = {
        let untagged = doku.untagged.or(serde.untagged);
        let content = doku.content.as_ref().or(serde.content.as_ref());
        let tag = doku.tag.as_ref().or(serde.tag.as_ref());

        let tag = if untagged.unwrap_or(false) {
            quote! {
                ::doku::Tag::None
            }
        } else {
            match (content, tag) {
                (Some(content), Some(tag)) => quote! {
                    ::doku::Tag::Adjacent {
                        content: #content,
                        tag: #tag,
                    }
                },

                (Some(_), None) => {
                    // This is illegal, but either rustc or serde should've
                    // issued an appropriate error message by now, so there's no
                    // need for us to linger too

                    quote! {
                        ::doku::Tag::External
                    }
                }

                (None, Some(tag)) => quote! {
                    ::doku::Tag::Internal {
                        tag: #tag,
                    }
                },

                (None, None) => quote! {
                    ::doku::Tag::External
                },
            }
        };

        let rename_variants =
            doku.rename_all.or(serde.rename_all).unwrap_or_default();
        let variants = expand_variants(&data.variants, rename_variants)?;

        quote! {
            ::doku::TypeKind::Enum {
                tag: #tag,
                variants: vec![ #(#variants)* ],
            }
        }
    };

    let ty = quote! {
        ::doku::Type::from( #ty_kind )
    };

    let generics = new_generics_with_where_clause(&input.generics)?;
    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();

    Ok(quote! {
        impl #impl_generics ::doku::Document for #ident #ty_generics #where_clause {
            fn ty() -> ::doku::Type {
                #ty
            }
        }
    })
}