Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add basic struct flattening support #16

Merged
merged 14 commits into from
Feb 11, 2022
Merged

Add basic struct flattening support #16

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
14 commits
Select commit Hold shift + click to select a range
e7af794
Added experimental flattening support
mitsuhiko Feb 10, 2022
ce2fa16
Initial attempt of serializing flattened fields
mitsuhiko Feb 10, 2022
a14db62
Merge branch 'main' into feature/flatten-serialize
mitsuhiko Feb 10, 2022
2f87f1b
Fix bad value_for_key code
mitsuhiko Feb 10, 2022
71a94fb
Change some methods to return results
mitsuhiko Feb 10, 2022
1ac48ae
Implement flatten deriving
mitsuhiko Feb 10, 2022
a98a900
Remove manual implementation of flattening in manual-struct example
mitsuhiko Feb 10, 2022
0e7da6d
Call finish when internal flattened struct is exhausted
mitsuhiko Feb 10, 2022
a333fb0
Fixed a bug with flatten and added basic tests
mitsuhiko Feb 10, 2022
f452a2c
Added support for nested optional skipping via flatten
mitsuhiko Feb 10, 2022
c304b50
Allow skip_serializing_if and flatten to coexist
mitsuhiko Feb 11, 2022
0188c5b
Added a test for skip_serializing_if with flatten
mitsuhiko Feb 11, 2022
85919ec
Document flatten and improve struct example
mitsuhiko Feb 11, 2022
1907530
Added changelog entry
mitsuhiko Feb 11, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions CHANGELOG.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,7 @@ All notable changes to deser are documented here.
directly on the `Sink`.
- The serializer state and deserializer state is now passed to `next_key`/
`next_value` and `next` on the sinks and emitters.
- Added support for `#[deser(flatten)]`.

## 0.5.0

Expand Down
22 changes: 22 additions & 0 deletions deser-derive/src/attr.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -270,6 +270,7 @@ pub struct FieldAttrs<'a> {
rename: Option<String>,
aliases: Vec<String>,
default: Option<TypeDefault>,
flatten: bool,
skip_serializing_if: Option<syn::ExprPath>,
}

Expand All @@ -280,6 +281,7 @@ impl<'a> FieldAttrs<'a> {
rename: None,
aliases: Vec::new(),
default: None,
flatten: false,
skip_serializing_if: None,
};

Expand Down Expand Up @@ -318,6 +320,15 @@ impl<'a> FieldAttrs<'a> {
"default", &nv.lit,
)?));
}
syn::Meta::Path(path) if path.is_ident("flatten") => {
if rv.flatten {
return Err(syn::Error::new_spanned(
meta,
"duplicate flatten attribute",
));
}
rv.flatten = true;
}
syn::Meta::NameValue(nv) if nv.path.is_ident("skip_serializing_if") => {
if rv.skip_serializing_if.is_some() {
return Err(syn::Error::new_spanned(
Expand All @@ -335,6 +346,13 @@ impl<'a> FieldAttrs<'a> {
}
}

if rv.flatten && rv.default.is_some() {
return Err(syn::Error::new_spanned(
field,
"cannot combine flatten and default",
));
}

Ok(rv)
}

Expand All @@ -357,6 +375,10 @@ impl<'a> FieldAttrs<'a> {
self.default.as_ref()
}

pub fn flatten(&self) -> bool {
self.flatten
}

pub fn skip_serializing_if(&self) -> Option<&syn::ExprPath> {
self.skip_serializing_if.as_ref()
}
Expand Down
121 changes: 99 additions & 22 deletions deser-derive/src/de.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,49 +27,79 @@ fn derive_struct(input: &syn::DeriveInput, fields: &syn::FieldsNamed) -> syn::Re

let container_attrs = ContainerAttrs::of(input)?;
let type_name = container_attrs.container_name();
let fieldname = &fields.named.iter().map(|f| &f.ident).collect::<Vec<_>>();
let fieldty = fields.named.iter().map(|f| &f.ty);
let sink_fieldname = &fields
let attrs = fields
.named
.iter()
.map(|f| {
.map(FieldAttrs::of)
.collect::<syn::Result<Vec<_>>>()?;
let fieldname = attrs.iter().map(|x| &x.field().ident).collect::<Vec<_>>();
let sink_fieldname = attrs
.iter()
.map(|x| {
syn::Ident::new(
&format!("field_{}", f.ident.as_ref().unwrap()),
&format!("field_{}", x.field().ident.as_ref().unwrap()),
Span::call_site(),
)
})
.collect::<Vec<_>>();
let attrs = fields
.named
let sink_fieldty = attrs
.iter()
.map(FieldAttrs::of)
.collect::<syn::Result<Vec<_>>>()?;
.map(|f| {
let ty = &f.field().ty;
if f.flatten() {
quote! {
::deser::de::OwnedSink<#ty>
}
} else {
quote! {
::deser::__derive::Option<#ty>
}
}
})
.collect::<Vec<_>>();
let sink_defaults = attrs
.iter()
.map(|f| {
if f.flatten() {
quote! {
::deser::de::OwnedSink::deserialize()
}
} else {
quote! {
::deser::__derive::None
}
}
})
.collect::<Vec<_>>();

let mut seen_names = HashSet::new();
let mut first_duplicate_name = None;
let matcher = attrs
.iter()
.map(|x| {
.zip(sink_fieldname.iter())
.filter_map(|(x, fieldname)| {
if x.flatten() {
return None;
}

let name = x.name(&container_attrs).to_string();
if first_duplicate_name.is_none() && seen_names.contains(&name) {
first_duplicate_name = Some((name.clone(), x.field()));
}
seen_names.insert(name.clone());

let mut rv = quote! {
::deser::__derive::Some(#name)
};
let mut rv = quote! { #name };
for alias in x.aliases() {
let alias = alias.clone();
if first_duplicate_name.is_none() && seen_names.contains(&alias) {
first_duplicate_name = Some((alias.clone(), x.field()));
}
seen_names.insert(alias.clone());
rv = quote! {
#rv | ::deser::__derive::Some(#alias)
};
rv = quote! { #rv | #alias };
}
rv
Some(quote! {
#rv => return ::deser::__derive::Ok(::deser::__derive::Some(::deser::Deserialize::deserialize_into(&mut self.#fieldname))),
})
})
.collect::<Vec<_>>();

Expand Down Expand Up @@ -103,6 +133,17 @@ fn derive_struct(input: &syn::DeriveInput, fields: &syn::FieldsNamed) -> syn::Re
.map(|(name, attrs)| {
if attrs.default().is_some() {
quote! { #name }
} else if attrs.flatten() {
// this should never happen unless the inner deserializer fucked up
let error = format!(
"Failed to deserialize flattened field '{}'",
attrs.name(&container_attrs)
);
quote! {
#name.ok_or_else(|| {
::deser::Error::new(::deser::ErrorKind::Unexpected, #error)
})?
}
} else if container_attrs.default().is_some() {
quote! { #name.unwrap() }
} else {
Expand All @@ -115,6 +156,19 @@ fn derive_struct(input: &syn::DeriveInput, fields: &syn::FieldsNamed) -> syn::Re
}
})
.collect::<Vec<_>>();
let flatten_fields = sink_fieldname
.iter()
.zip(attrs.iter())
.filter_map(
|(name, attrs)| {
if attrs.flatten() {
Some(name)
} else {
None
}
},
)
.collect::<Vec<_>>();

let stage2_default = if container_attrs.default().is_some() {
let need_container_default = sink_fieldname
Expand Down Expand Up @@ -164,10 +218,11 @@ fn derive_struct(input: &syn::DeriveInput, fields: &syn::FieldsNamed) -> syn::Re
slot: &'__a mut ::deser::__derive::Option<#ident #ty_generics>,
key: ::deser::__derive::Option<String>,
#(
#sink_fieldname: ::deser::__derive::Option<#fieldty>,
#sink_fieldname: #sink_fieldty,
)*
}

#[automatically_derived]
impl #impl_generics ::deser::Deserialize for #ident #ty_generics #bounded_where_clause {
fn deserialize_into(
__slot: &mut ::deser::__derive::Option<Self>,
Expand All @@ -176,12 +231,13 @@ fn derive_struct(input: &syn::DeriveInput, fields: &syn::FieldsNamed) -> syn::Re
slot: __slot,
key: ::deser::__derive::None,
#(
#sink_fieldname: ::deser::__derive::None,
#sink_fieldname: #sink_defaults,
)*
})
}
}

#[automatically_derived]
impl #wrapper_impl_generics ::deser::de::Sink for __Sink #wrapper_ty_generics #bounded_where_clause {
fn descriptor(&self) -> &dyn ::deser::Descriptor {
&__Descriptor
Expand All @@ -202,16 +258,36 @@ fn derive_struct(input: &syn::DeriveInput, fields: &syn::FieldsNamed) -> syn::Re
fn next_value(&mut self, __state: &::deser::de::DeserializerState)
-> ::deser::__derive::Result<::deser::de::SinkHandle>
{
match self.key.take().as_deref() {
let __key = self.key.take().unwrap();
::deser::__derive::Ok(match self.value_for_key(&__key, __state)? {
::deser::__derive::Some(__sink) => __sink,
::deser::__derive::None => ::deser::de::SinkHandle::null(),
})
}

fn value_for_key(&mut self, __key: &str, __state: &::deser::de::DeserializerState)
-> ::deser::__derive::Result<::deser::__derive::Option<::deser::de::SinkHandle>>
{
match __key {
#(
#matcher => ::deser::__derive::Ok(::deser::Deserialize::deserialize_into(&mut self.#sink_fieldname)),
#matcher
)*
_ => ::deser::__derive::Ok(::deser::de::SinkHandle::null()),
__other => {
#(
if let ::deser::__derive::Some(__sink) = self.#flatten_fields.borrow_mut().value_for_key(__other, __state)? {
return ::deser::__derive::Ok(::deser::__derive::Some(__sink));
}
)*
}
}
::deser::__derive::Ok(::deser::__derive::None)
}

fn finish(&mut self, __state: &::deser::de::DeserializerState) -> ::deser::__derive::Result<()> {
#![allow(unused_mut)]
#(
self.#flatten_fields.borrow_mut().finish(__state)?;
)*
#(
let mut #sink_fieldname = self.#sink_fieldname.#field_stage1_default;
)*
Expand Down Expand Up @@ -316,6 +392,7 @@ pub fn derive_enum(
slot: ::deser::__derive::Option<#ident>,
}

#[automatically_derived]
impl ::deser::de::Deserialize for #ident {
fn deserialize_into(
__slot: &mut ::deser::__derive::Option<Self>
Expand Down
Loading