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|
use darling::FromAttributes;
use proc_macro::TokenStream;
use proc_macro2::TokenStream as TokenStream2;
use quote::quote;
use syn::{parse, ItemStruct};
#[derive(Debug, Default, FromAttributes)]
#[darling(attributes(ppproperly))]
#[darling(default)]
struct Args {
len_for: Option<String>,
discriminant_for: Option<String>,
}
#[proc_macro_derive(Serialize)]
pub fn derive_serialize(item: TokenStream) -> TokenStream {
let ast: ItemStruct = parse(item).unwrap();
let name = ast.ident;
let serializers = ast.fields.iter().map(|field| {
let field_name = field.ident.as_ref().expect("should be a names struct");
quote!(
self.#field_name.serialize(w)?;
)
});
quote!(
impl Serialize for #name {
fn serialize<W: std::io::Write>(&self, w: &mut W) -> Result<()> {
#(#serializers) *
Ok(())
}
}
)
.into()
}
#[proc_macro_derive(Deserialize, attributes(ppproperly))]
pub fn derive_deserialize(item: TokenStream) -> TokenStream {
let ast: ItemStruct = parse(item).unwrap();
let name = ast.ident;
let deserializers = ast.fields.iter().map(|field| {
let mut out = TokenStream2::new();
let field_name = field.ident.as_ref().expect("should be a names struct");
let args = Args::from_attributes(&field.attrs).unwrap();
out.extend(
vec![quote!(
let mut len_for = std::collections::HashMap::new();
let mut discriminant_for = std::collections::HashMap::new();
)]
.into_iter(),
);
if let Some(attr) = args.len_for {
out.extend(
vec![quote!(
let mut len = 0u16;
len.deserialize(r)?;
len_for.insert(#attr, len);
)]
.into_iter(),
);
}
if let Some(attr) = args.discriminant_for {
out.extend(
vec![quote!(
let mut discriminant = 0u8;
discriminant.deserialize(r)?;
discriminant_for.insert(#attr, discriminant);
)]
.into_iter(),
);
}
out.extend(
vec![quote!(
let r = if let Some(attr) = len_for.get("#field_name") {
r.take(attr)
} else {
r
};
)]
.into_iter(),
);
out.extend(
vec![quote!(
if let Some(attr) = discriminant_for.get("#field_name") {
self.#field_name.deserialize_with_discriminant(r, attr)?;
} else {
self.#field_name.deserialize(r)?;
}
)]
.into_iter(),
);
out
});
quote!(
impl Deserialize for #name {
fn deserialize<R: std::io::Read>(&mut self, r: &mut R) -> Result<()> {
#(#deserializers) *
Ok(())
}
}
)
.into()
}
|
