sea_query_derive/
enum_def.rs

1use darling::FromMeta;
2use heck::{ToPascalCase, ToSnakeCase};
3use proc_macro::{self, TokenStream};
4use quote::quote_spanned;
5use syn::{Data, DataStruct, DeriveInput, Fields, Ident, parse_macro_input, spanned::Spanned};
6
7use crate::iden::{GenEnumArgs, NamingHolder};
8
9pub fn expand(args: TokenStream, input: TokenStream) -> TokenStream {
10    let attr_args = match darling::ast::NestedMeta::parse_meta_list(args.into()) {
11        Ok(v) => v,
12        Err(e) => {
13            return TokenStream::from(darling::Error::from(e).write_errors());
14        }
15    };
16    let input = parse_macro_input!(input as DeriveInput);
17
18    let args = match GenEnumArgs::from_list(&attr_args) {
19        Ok(v) => v,
20        Err(e) => {
21            return TokenStream::from(e.write_errors());
22        }
23    };
24
25    let fields =
26        match &input.data {
27            Data::Struct(DataStruct {
28                fields: Fields::Named(fields),
29                ..
30            }) => &fields.named,
31            _ => return quote_spanned! {
32                input.span() => compile_error!("#[enum_def] can only be used on non-tuple structs");
33            }
34            .into(),
35        };
36
37    let field_names: Vec<NamingHolder> = fields
38        .iter()
39        .map(|field| {
40            let ident = field.ident.as_ref().unwrap();
41            NamingHolder {
42                default: ident.clone(),
43                pascal: Ident::new(ident.to_string().to_pascal_case().as_str(), ident.span()),
44            }
45        })
46        .collect();
47
48    let table_name = Ident::new(
49        args.table_name
50            .unwrap_or_else(|| input.ident.to_string().to_snake_case())
51            .as_str(),
52        input.ident.span(),
53    );
54
55    let enum_name = quote::format_ident!(
56        "{}{}{}",
57        args.prefix
58            .unwrap_or_else(|| crate::iden::DEFAULT_PREFIX.to_string()),
59        &input.ident,
60        args.suffix
61            .unwrap_or_else(|| crate::iden::DEFAULT_SUFFIX.to_string())
62    );
63    let pascal_def_names = field_names.iter().map(|field| &field.pascal);
64    let pascal_def_names2 = pascal_def_names.clone();
65    let default_names = field_names.iter().map(|field| &field.default);
66    let default_names2 = default_names.clone();
67    let import_name = Ident::new(
68        args.crate_name
69            .unwrap_or_else(|| crate::iden::DEFAULT_CRATE_NAME.to_string())
70            .as_str(),
71        input.span(),
72    );
73
74    TokenStream::from(quote::quote! {
75        #input
76
77        #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
78        pub enum #enum_name {
79            Table,
80            #(#pascal_def_names,)*
81        }
82
83        impl #import_name::IdenStatic for #enum_name {
84            fn as_str(&self) -> &'static str {
85                match self {
86                    #enum_name::Table => stringify!(#table_name),
87                    #(#enum_name::#pascal_def_names2 => stringify!(#default_names2)),*
88                }
89            }
90        }
91
92        impl #import_name::Iden for #enum_name {
93            fn unquoted(&self) -> &str {
94                <Self as #import_name::IdenStatic>::as_str(&self)
95            }
96        }
97
98        impl ::std::convert::AsRef<str> for #enum_name {
99            fn as_ref(&self) -> &str {
100                <Self as #import_name::IdenStatic>::as_str(&self)
101            }
102        }
103    })
104}
sea_query_derive/enum_def.rs

sea_query_derive/
enum_def.rs
