2021-05-18 18:43:14 +08:00

59 lines
1.7 KiB
Rust

use heck::SnakeCase;
use proc_macro2::{Ident, TokenStream};
use quote::{quote, quote_spanned};
use syn::{Data, DataEnum, Fields, Variant};
pub fn expend_derive_primary_key(ident: Ident, data: Data) -> syn::Result<TokenStream> {
let variants = match data {
syn::Data::Enum(DataEnum { variants, .. }) => variants,
_ => {
return Ok(quote_spanned! {
ident.span() => compile_error!("you can only derive DerivePrimaryKey on enums");
})
}
};
let variant: Vec<TokenStream> = variants
.iter()
.map(|Variant { ident, fields, .. }| match fields {
Fields::Named(_) => quote! { #ident{..} },
Fields::Unnamed(_) => quote! { #ident(..) },
Fields::Unit => quote! { #ident },
})
.collect();
let name: Vec<TokenStream> = variants
.iter()
.map(|v| {
let ident = v.ident.to_string().to_snake_case();
quote! { #ident }
})
.collect();
Ok(quote!(
impl sea_orm::Iden for #ident {
fn unquoted(&self, s: &mut dyn std::fmt::Write) {
write!(s, "{}", self.as_str()).unwrap();
}
}
impl sea_orm::IdenStatic for #ident {
fn as_str(&self) -> &str {
match self {
#(Self::#variant => #name),*
}
}
}
impl sea_orm::PrimaryKeyTrait for #ident {}
impl sea_orm::PrimaryKeyOfModel<Model> for #ident {
fn into_column(self) -> <Model as ModelTrait>::Column {
match self {
#(Self::#variant => Column::#variant),*
}
}
}
))
}