Support (de)serialize_with in tuples

This commit is contained in:
David Tolnay 2016-05-15 15:54:20 -07:00
parent cc115ca43a
commit 938f42faf6
4 changed files with 353 additions and 311 deletions

View File

@ -177,31 +177,29 @@ pub struct FieldAttrs {
name: Name,
skip_serializing_field: bool,
skip_deserializing_field: bool,
skip_serializing_field_if: Option<P<ast::Expr>>,
skip_serializing_if: Option<ast::Path>,
default_expr_if_missing: Option<P<ast::Expr>>,
serialize_with: Option<P<ast::Expr>>,
serialize_with: Option<ast::Path>,
deserialize_with: Option<ast::Path>,
}
impl FieldAttrs {
/// Extract out the `#[serde(...)]` attributes from a struct field.
pub fn from_field(cx: &ExtCtxt,
container_ty: &P<ast::Ty>,
generics: &ast::Generics,
field: &ast::StructField,
is_enum: bool) -> Result<Self, Error> {
index: usize,
field: &ast::StructField) -> Result<Self, Error> {
let builder = AstBuilder::new();
let field_ident = match field.ident {
Some(ident) => ident,
None => { cx.span_bug(field.span, "struct field has no name?") }
None => builder.id(index.to_string()),
};
let mut field_attrs = FieldAttrs {
name: Name::new(field_ident),
skip_serializing_field: false,
skip_deserializing_field: false,
skip_serializing_field_if: None,
skip_serializing_if: None,
default_expr_if_missing: None,
serialize_with: None,
deserialize_with: None,
@ -260,27 +258,14 @@ impl FieldAttrs {
// Parse `#[serde(skip_serializing_if="...")]`
ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"skip_serializing_if" => {
let expr = wrap_skip_serializing(
field_ident,
try!(parse_lit_into_path(cx, name, lit)),
is_enum,
);
field_attrs.skip_serializing_field_if = Some(expr);
let path = try!(parse_lit_into_path(cx, name, lit));
field_attrs.skip_serializing_if = Some(path);
}
// Parse `#[serde(serialize_with="...")]`
ast::MetaItemKind::NameValue(ref name, ref lit) if name == &"serialize_with" => {
let expr = wrap_serialize_with(
cx,
container_ty,
generics,
field_ident,
try!(parse_lit_into_path(cx, name, lit)),
is_enum,
);
field_attrs.serialize_with = Some(expr);
let path = try!(parse_lit_into_path(cx, name, lit));
field_attrs.serialize_with = Some(path);
}
// Parse `#[serde(deserialize_with="...")]`
@ -316,15 +301,15 @@ impl FieldAttrs {
self.skip_deserializing_field
}
pub fn skip_serializing_field_if(&self) -> Option<&P<ast::Expr>> {
self.skip_serializing_field_if.as_ref()
pub fn skip_serializing_if(&self) -> Option<&ast::Path> {
self.skip_serializing_if.as_ref()
}
pub fn default_expr_if_missing(&self) -> Option<&P<ast::Expr>> {
self.default_expr_if_missing.as_ref()
}
pub fn serialize_with(&self) -> Option<&P<ast::Expr>> {
pub fn serialize_with(&self) -> Option<&ast::Path> {
self.serialize_with.as_ref()
}
@ -334,14 +319,17 @@ impl FieldAttrs {
}
/// Extract out the `#[serde(...)]` attributes from a struct field.
pub fn get_struct_field_attrs(cx: &ExtCtxt,
container_ty: &P<ast::Ty>,
generics: &ast::Generics,
fields: &[ast::StructField],
is_enum: bool) -> Result<Vec<FieldAttrs>, Error> {
/// Zip together fields and `#[serde(...)]` attributes on those fields.
pub fn fields_with_attrs<'a>(
cx: &ExtCtxt,
fields: &'a [ast::StructField],
) -> Result<Vec<(&'a ast::StructField, FieldAttrs)>, Error> {
fields.iter()
.map(|field| FieldAttrs::from_field(cx, container_ty, generics, field, is_enum))
.enumerate()
.map(|(i, field)| {
let attrs = try!(FieldAttrs::from_field(cx, i, field));
Ok((field, attrs))
})
.collect()
}
@ -495,100 +483,3 @@ fn wrap_default(path: ast::Path) -> P<ast::Expr> {
.build_path(path)
.build()
}
/// This function wraps the expression in `#[serde(skip_serializing_if="...")]` in a trait to
/// prevent it from accessing the internal `Serialize` state.
fn wrap_skip_serializing(field_ident: ast::Ident,
path: ast::Path,
is_enum: bool) -> P<ast::Expr> {
let builder = AstBuilder::new();
let expr = builder.expr()
.field(field_ident)
.field("value")
.self_();
let expr = if is_enum {
expr
} else {
builder.expr().ref_().build(expr)
};
builder.expr().call()
.build_path(path)
.arg().build(expr)
.build()
}
/// This function wraps the expression in `#[serde(serialize_with="...")]` in a trait to
/// prevent it from accessing the internal `Serialize` state.
fn wrap_serialize_with(cx: &ExtCtxt,
container_ty: &P<ast::Ty>,
generics: &ast::Generics,
field_ident: ast::Ident,
path: ast::Path,
is_enum: bool) -> P<ast::Expr> {
let builder = AstBuilder::new();
let expr = builder.expr()
.field(field_ident)
.self_();
let expr = if is_enum {
expr
} else {
builder.expr().ref_().build(expr)
};
let expr = builder.expr().call()
.build_path(path)
.arg().build(expr)
.arg()
.id("serializer")
.build();
let where_clause = &generics.where_clause;
quote_expr!(cx, {
trait __SerdeSerializeWith {
fn __serde_serialize_with<__S>(&self, serializer: &mut __S) -> Result<(), __S::Error>
where __S: _serde::ser::Serializer;
}
impl<'__a, __T> __SerdeSerializeWith for &'__a __T
where __T: '__a + __SerdeSerializeWith,
{
fn __serde_serialize_with<__S>(&self, serializer: &mut __S) -> Result<(), __S::Error>
where __S: _serde::ser::Serializer
{
(**self).__serde_serialize_with(serializer)
}
}
impl $generics __SerdeSerializeWith for $container_ty $where_clause {
fn __serde_serialize_with<__S>(&self, serializer: &mut __S) -> Result<(), __S::Error>
where __S: _serde::ser::Serializer
{
$expr
}
}
struct __SerdeSerializeWithStruct<'__a, __T: '__a> {
value: &'__a __T,
}
impl<'__a, __T> _serde::ser::Serialize for __SerdeSerializeWithStruct<'__a, __T>
where __T: '__a + __SerdeSerializeWith
{
fn serialize<__S>(&self, serializer: &mut __S) -> Result<(), __S::Error>
where __S: _serde::ser::Serializer
{
self.value.__serde_serialize_with(serializer)
}
}
__SerdeSerializeWithStruct {
value: &self.value,
}
})
}

View File

@ -214,7 +214,7 @@ fn deserialize_item_struct(
None,
impl_generics,
ty,
fields.len(),
fields,
container_attrs,
)
}
@ -358,7 +358,7 @@ fn deserialize_tuple(
variant_ident: Option<Ident>,
impl_generics: &ast::Generics,
ty: P<ast::Ty>,
fields: usize,
fields: &[ast::StructField],
container_attrs: &attr::ContainerAttrs,
) -> Result<P<ast::Expr>, Error> {
let where_clause = &impl_generics.where_clause;
@ -376,37 +376,43 @@ fn deserialize_tuple(
None => builder.path().id(type_ident).build(),
};
let visit_newtype_struct = if !is_enum && fields == 1 {
Some(quote_tokens!(cx,
#[inline]
fn visit_newtype_struct<__E>(&mut self, deserializer: &mut __E) -> ::std::result::Result<Self::Value, __E::Error>
where __E: _serde::de::Deserializer,
{
let value = try!(_serde::de::Deserialize::deserialize(deserializer));
Ok($type_path(value))
}))
let nfields = fields.len();
let fields_with_attrs = try!(attr::fields_with_attrs(cx, fields));
let visit_newtype_struct = if !is_enum && nfields == 1 {
Some(try!(deserialize_newtype_struct(
cx,
builder,
type_ident,
&type_path,
impl_generics,
&fields_with_attrs[0],
)))
} else {
None
};
let visit_seq_expr = deserialize_seq(
let visit_seq_expr = try!(deserialize_seq(
cx,
builder,
type_ident,
type_path,
fields,
);
impl_generics,
&fields_with_attrs,
false,
));
let dispatch = if is_enum {
quote_expr!(cx,
visitor.visit_tuple($fields, $visitor_expr))
} else if fields == 1 {
visitor.visit_tuple($nfields, $visitor_expr))
} else if nfields == 1 {
let type_name = container_attrs.name().deserialize_name_expr();
quote_expr!(cx,
deserializer.deserialize_newtype_struct($type_name, $visitor_expr))
} else {
let type_name = container_attrs.name().deserialize_name_expr();
quote_expr!(cx,
deserializer.deserialize_tuple_struct($type_name, $fields, $visitor_expr))
deserializer.deserialize_tuple_struct($type_name, $nfields, $visitor_expr))
};
Ok(quote_expr!(cx, {
@ -430,46 +436,13 @@ fn deserialize_tuple(
}
fn deserialize_seq(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
struct_path: ast::Path,
fields: usize,
) -> P<ast::Expr> {
let let_values: Vec<ast::Stmt> = (0 .. fields)
.map(|i| {
let name = builder.id(format!("__field{}", i));
quote_stmt!(cx,
let $name = match try!(visitor.visit()) {
Some(value) => { value },
None => {
return Err(_serde::de::Error::end_of_stream());
}
};
).unwrap()
})
.collect();
let result = builder.expr().call()
.build_path(struct_path)
.with_args((0 .. fields).map(|i| builder.expr().id(format!("__field{}", i))))
.build();
quote_expr!(cx, {
$let_values
try!(visitor.end());
Ok($result)
})
}
fn deserialize_struct_as_seq(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
type_ident: Ident,
struct_path: ast::Path,
type_path: ast::Path,
impl_generics: &ast::Generics,
fields: &[(&ast::StructField, attr::FieldAttrs)],
is_struct: bool,
) -> Result<P<ast::Expr>, Error> {
let let_values: Vec<_> = fields.iter()
.enumerate()
@ -508,7 +481,8 @@ fn deserialize_struct_as_seq(
})
.collect();
let result = builder.expr().struct_path(struct_path)
let result = if is_struct {
builder.expr().struct_path(type_path)
.with_id_exprs(
fields.iter()
.enumerate()
@ -524,7 +498,13 @@ fn deserialize_struct_as_seq(
)
})
)
.build();
.build()
} else {
builder.expr().call()
.build_path(type_path)
.with_args((0..fields.len()).map(|i| builder.expr().id(format!("__field{}", i))))
.build()
};
Ok(quote_expr!(cx, {
$let_values
@ -535,6 +515,41 @@ fn deserialize_struct_as_seq(
}))
}
fn deserialize_newtype_struct(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
type_ident: Ident,
type_path: &ast::Path,
impl_generics: &ast::Generics,
field: &(&ast::StructField, attr::FieldAttrs),
) -> Result<Vec<ast::TokenTree>, Error> {
let &(field, ref attrs) = field;
let value = match attrs.deserialize_with() {
None => {
let field_ty = &field.ty;
quote_expr!(cx,
try!(<$field_ty as _serde::Deserialize>::deserialize(__e)))
}
Some(path) => {
let (wrapper, wrapper_impl, wrapper_ty) = wrap_deserialize_with(
cx, builder, type_ident, impl_generics, &field.ty, path);
quote_expr!(cx, {
$wrapper
$wrapper_impl
try!(<$wrapper_ty as _serde::Deserialize>::deserialize(__e)).value
})
}
};
Ok(quote_tokens!(cx,
#[inline]
fn visit_newtype_struct<__E>(&mut self, __e: &mut __E) -> ::std::result::Result<Self::Value, __E::Error>
where __E: _serde::de::Deserializer,
{
Ok($type_path($value))
}
))
}
fn deserialize_struct(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
@ -559,16 +574,16 @@ fn deserialize_struct(
None => builder.path().id(type_ident).build(),
};
let is_enum = variant_ident.is_some();
let fields_with_attrs = try!(fields_with_attrs(cx, impl_generics, &ty, fields, is_enum));
let fields_with_attrs = try!(attr::fields_with_attrs(cx, fields));
let visit_seq_expr = try!(deserialize_struct_as_seq(
let visit_seq_expr = try!(deserialize_seq(
cx,
builder,
type_ident,
type_path.clone(),
impl_generics,
&fields_with_attrs,
true,
));
let (field_visitor, fields_stmt, visit_map_expr) = try!(deserialize_struct_visitor(
@ -581,6 +596,7 @@ fn deserialize_struct(
container_attrs,
));
let is_enum = variant_ident.is_some();
let dispatch = if is_enum {
quote_expr!(cx,
visitor.visit_struct(FIELDS, $visitor_expr))
@ -737,10 +753,14 @@ fn deserialize_variant(
}))
}
ast::VariantData::Tuple(ref fields, _) if fields.len() == 1 => {
Ok(quote_expr!(cx, {
let val = try!(visitor.visit_newtype());
Ok($type_ident::$variant_ident(val))
}))
deserialize_newtype_variant(
cx,
builder,
type_ident,
variant_ident,
generics,
&fields[0],
)
}
ast::VariantData::Tuple(ref fields, _) => {
deserialize_tuple(
@ -750,7 +770,7 @@ fn deserialize_variant(
Some(variant_ident),
generics,
ty,
fields.len(),
fields,
container_attrs,
)
}
@ -769,6 +789,33 @@ fn deserialize_variant(
}
}
fn deserialize_newtype_variant(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
type_ident: Ident,
variant_ident: Ident,
impl_generics: &ast::Generics,
field: &ast::StructField,
) -> Result<P<ast::Expr>, Error> {
let attrs = try!(attr::FieldAttrs::from_field(cx, 0, field));
let visit = match attrs.deserialize_with() {
None => {
let field_ty = &field.ty;
quote_expr!(cx, try!(visitor.visit_newtype::<$field_ty>()))
}
Some(path) => {
let (wrapper, wrapper_impl, wrapper_ty) = wrap_deserialize_with(
cx, builder, type_ident, impl_generics, &field.ty, path);
quote_expr!(cx, {
$wrapper
$wrapper_impl
try!(visitor.visit_newtype::<$wrapper_ty>()).value
})
}
};
Ok(quote_expr!(cx, Ok($type_ident::$variant_ident($visit))))
}
fn deserialize_field_visitor(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
@ -1117,21 +1164,6 @@ fn deserialize_map(
}))
}
fn fields_with_attrs<'a>(
cx: &ExtCtxt,
generics: &ast::Generics,
ty: &P<ast::Ty>,
fields: &'a [ast::StructField],
is_enum: bool
) -> Result<Vec<(&'a ast::StructField, attr::FieldAttrs)>, Error> {
fields.iter()
.map(|field| {
let attrs = try!(attr::FieldAttrs::from_field(cx, &ty, generics, field, is_enum));
Ok((field, attrs))
})
.collect()
}
/// This function wraps the expression in `#[serde(deserialize_with="...")]` in
/// a trait to prevent it from accessing the internal `Deserialize` state.
fn wrap_deserialize_with(

View File

@ -185,6 +185,10 @@ fn serialize_item_struct(
ast::VariantData::Tuple(ref fields, _) if fields.len() == 1 => {
serialize_newtype_struct(
cx,
&builder,
impl_generics,
ty,
&fields[0],
container_attrs,
)
}
@ -198,7 +202,7 @@ fn serialize_item_struct(
&builder,
impl_generics,
ty,
fields.len(),
fields,
container_attrs,
)
}
@ -232,12 +236,24 @@ fn serialize_unit_struct(
fn serialize_newtype_struct(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
impl_generics: &ast::Generics,
container_ty: P<ast::Ty>,
field: &ast::StructField,
container_attrs: &attr::ContainerAttrs,
) -> Result<P<ast::Expr>, Error> {
let type_name = container_attrs.name().serialize_name_expr();
let attrs = try!(attr::FieldAttrs::from_field(cx, 0, field));
let mut field_expr = quote_expr!(cx, &self.0);
if let Some(path) = attrs.serialize_with() {
field_expr = wrap_serialize_with(cx, builder,
&container_ty, impl_generics, &field.ty, path, field_expr);
}
Ok(quote_expr!(cx,
_serializer.serialize_newtype_struct($type_name, &self.0)
_serializer.serialize_newtype_struct($type_name, $field_expr)
))
}
@ -246,10 +262,10 @@ fn serialize_tuple_struct(
builder: &aster::AstBuilder,
impl_generics: &ast::Generics,
ty: P<ast::Ty>,
fields: usize,
fields: &[ast::StructField],
container_attrs: &attr::ContainerAttrs,
) -> Result<P<ast::Expr>, Error> {
let (visitor_struct, visitor_impl) = serialize_tuple_struct_visitor(
let (visitor_struct, visitor_impl) = try!(serialize_tuple_struct_visitor(
cx,
builder,
ty.clone(),
@ -260,7 +276,8 @@ fn serialize_tuple_struct(
builder.id("serialize_tuple_struct_elt"),
fields,
impl_generics,
);
false,
));
let type_name = container_attrs.name().serialize_name_expr();
@ -362,12 +379,8 @@ fn serialize_variant(
match variant.node.data {
ast::VariantData::Unit(_) => {
let pat = builder.pat().path()
.id(type_ident).id(variant_ident)
.build();
Ok(quote_arm!(cx,
$pat => {
$type_ident::$variant_ident => {
_serde::ser::Serializer::serialize_unit_variant(
_serializer,
$type_name,
@ -378,23 +391,19 @@ fn serialize_variant(
))
},
ast::VariantData::Tuple(ref fields, _) if fields.len() == 1 => {
let field = builder.id("__simple_value");
let field = builder.pat().ref_id(field);
let pat = builder.pat().enum_()
.id(type_ident).id(variant_ident).build()
.with_pats(Some(field).into_iter())
.build();
let expr = try!(serialize_newtype_variant(
cx,
builder,
type_name,
variant_index,
variant_name,
ty,
generics,
&fields[0],
));
Ok(quote_arm!(cx,
$pat => {
_serde::ser::Serializer::serialize_newtype_variant(
_serializer,
$type_name,
$variant_index,
$variant_name,
__simple_value,
)
}
$type_ident::$variant_ident(ref __simple_value) => { $expr }
))
},
ast::VariantData::Tuple(ref fields, _) => {
@ -410,7 +419,7 @@ fn serialize_variant(
)
.build();
let expr = serialize_tuple_variant(
let expr = try!(serialize_tuple_variant(
cx,
builder,
type_name,
@ -420,7 +429,7 @@ fn serialize_variant(
ty,
fields,
field_names,
);
));
Ok(quote_arm!(cx,
$pat => { $expr }
@ -468,6 +477,35 @@ fn serialize_variant(
}
}
fn serialize_newtype_variant(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
type_name: P<ast::Expr>,
variant_index: usize,
variant_name: P<ast::Expr>,
container_ty: P<ast::Ty>,
generics: &ast::Generics,
field: &ast::StructField,
) -> Result<P<ast::Expr>, Error> {
let attrs = try!(attr::FieldAttrs::from_field(cx, 0, field));
let mut field_expr = quote_expr!(cx, __simple_value);
if let Some(path) = attrs.serialize_with() {
field_expr = wrap_serialize_with(cx, builder,
&container_ty, generics, &field.ty, path, field_expr);
}
Ok(quote_expr!(cx,
_serde::ser::Serializer::serialize_newtype_variant(
_serializer,
$type_name,
$variant_index,
$variant_name,
$field_expr,
)
))
}
fn serialize_tuple_variant(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
@ -478,7 +516,7 @@ fn serialize_tuple_variant(
structure_ty: P<ast::Ty>,
fields: &[ast::StructField],
field_names: Vec<Ident>,
) -> P<ast::Expr> {
) -> Result<P<ast::Expr>, Error> {
let variant_ty = builder.ty().tuple()
.with_tys(
fields.iter().map(|field| {
@ -490,15 +528,16 @@ fn serialize_tuple_variant(
)
.build();
let (visitor_struct, visitor_impl) = serialize_tuple_struct_visitor(
let (visitor_struct, visitor_impl) = try!(serialize_tuple_struct_visitor(
cx,
builder,
structure_ty.clone(),
variant_ty,
builder.id("serialize_tuple_variant_elt"),
fields.len(),
fields,
generics,
);
true,
));
let value_expr = builder.expr().tuple()
.with_exprs(
@ -508,7 +547,7 @@ fn serialize_tuple_variant(
)
.build();
quote_expr!(cx, {
Ok(quote_expr!(cx, {
$visitor_struct
$visitor_impl
_serializer.serialize_tuple_variant($type_name, $variant_index, $variant_name, Visitor {
@ -516,7 +555,7 @@ fn serialize_tuple_variant(
state: 0,
_structure_ty: ::std::marker::PhantomData::<&$structure_ty>,
})
})
}))
}
fn serialize_struct_variant(
@ -614,20 +653,33 @@ fn serialize_tuple_struct_visitor(
structure_ty: P<ast::Ty>,
variant_ty: P<ast::Ty>,
serializer_method: ast::Ident,
fields: usize,
generics: &ast::Generics
) -> (P<ast::Item>, P<ast::Item>) {
let arms: Vec<ast::Arm> = (0 .. fields)
.map(|i| {
let expr = builder.expr().method_call(serializer_method)
.id("_serializer")
.arg().ref_().tup_field(i).field("value").self_()
.build();
fields: &[ast::StructField],
generics: &ast::Generics,
is_enum: bool,
) -> Result<(P<ast::Item>, P<ast::Item>), Error> {
let fields_with_attrs = try!(attr::fields_with_attrs(cx, fields));
let arms: Vec<_> = fields_with_attrs.iter()
.enumerate()
.map(|(i, &(field, ref attrs))| {
let mut field_expr = builder.expr().tup_field(i).field("value").self_();
if !is_enum {
field_expr = quote_expr!(cx, &$field_expr);
}
let continue_if_skip = attrs.skip_serializing_if()
.map(|path| quote_stmt!(cx, if $path($field_expr) { continue }));
if let Some(path) = attrs.serialize_with() {
field_expr = wrap_serialize_with(cx, builder,
&structure_ty, generics, &field.ty, path, field_expr);
}
quote_arm!(cx,
$i => {
self.state += 1;
Ok(Some(try!($expr)))
$continue_if_skip
Ok(Some(try!(_serializer.$serializer_method($field_expr))))
}
)
})
@ -644,7 +696,9 @@ fn serialize_tuple_struct_visitor(
.strip_bounds()
.build();
(
let nfields = fields.len();
Ok((
quote_item!(cx,
struct Visitor $visitor_impl_generics $where_clause {
state: usize,
@ -669,11 +723,11 @@ fn serialize_tuple_struct_visitor(
#[inline]
fn len(&self) -> Option<usize> {
Some($fields)
Some($nfields)
}
}
).unwrap(),
)
))
}
fn serialize_struct_visitor(
@ -686,28 +740,27 @@ fn serialize_struct_visitor(
generics: &ast::Generics,
is_enum: bool,
) -> Result<(P<ast::Item>, P<ast::Item>), Error> {
let field_attrs = try!(
attr::get_struct_field_attrs(cx, &structure_ty, generics, fields, is_enum)
);
let fields_with_attrs = try!(attr::fields_with_attrs(cx, fields));
let arms: Vec<ast::Arm> = fields.iter().zip(field_attrs.iter())
.filter(|&(_, ref field_attr)| !field_attr.skip_serializing_field())
let arms: Vec<ast::Arm> = fields_with_attrs.iter()
.filter(|&&(_, ref attrs)| !attrs.skip_serializing_field())
.enumerate()
.map(|(i, (ref field, ref field_attr))| {
let name = field.ident.expect("struct has unnamed field");
.map(|(i, &(field, ref attrs))| {
let ident = field.ident.expect("struct has unnamed field");
let mut field_expr = quote_expr!(cx, self.value.$ident);
if !is_enum {
field_expr = quote_expr!(cx, &$field_expr);
}
let key_expr = field_attr.name().serialize_name_expr();
let key_expr = attrs.name().serialize_name_expr();
let stmt = if let Some(expr) = field_attr.skip_serializing_field_if() {
Some(quote_stmt!(cx, if $expr { continue; }))
} else {
None
};
let continue_if_skip = attrs.skip_serializing_if()
.map(|path| quote_stmt!(cx, if $path($field_expr) { continue }));
let field_expr = match field_attr.serialize_with() {
Some(expr) => expr.clone(),
None => quote_expr!(cx, &self.value.$name),
};
if let Some(path) = attrs.serialize_with() {
field_expr = wrap_serialize_with(cx, builder,
&structure_ty, generics, &field.ty, path, field_expr)
}
let expr = quote_expr!(cx,
_serializer.$serializer_method($key_expr, $field_expr)
@ -716,7 +769,7 @@ fn serialize_struct_visitor(
quote_arm!(cx,
$i => {
self.state += 1;
$stmt
$continue_if_skip
return Ok(Some(try!($expr)));
}
)
@ -734,16 +787,18 @@ fn serialize_struct_visitor(
.strip_bounds()
.build();
let len = field_attrs.iter()
.filter(|field_attr| !field_attr.skip_serializing_field())
.map(|field_attr| {
match field_attr.skip_serializing_field_if() {
Some(expr) => {
quote_expr!(cx, if $expr { 0 } else { 1 })
}
None => {
quote_expr!(cx, 1)
let len = fields_with_attrs.iter()
.filter(|&&(_, ref attrs)| !attrs.skip_serializing_field())
.map(|&(field, ref attrs)| {
let ident = field.ident.expect("struct has unnamed fields");
let mut field_expr = quote_expr!(cx, self.value.$ident);
if !is_enum {
field_expr = quote_expr!(cx, &$field_expr);
}
match attrs.skip_serializing_if() {
Some(path) => quote_expr!(cx, if $path($field_expr) { 0 } else { 1 }),
None => quote_expr!(cx, 1),
}
})
.fold(quote_expr!(cx, 0), |sum, expr| quote_expr!(cx, $sum + $expr));
@ -782,3 +837,46 @@ fn serialize_struct_visitor(
).unwrap(),
))
}
fn wrap_serialize_with(
cx: &ExtCtxt,
builder: &aster::AstBuilder,
container_ty: &P<ast::Ty>,
generics: &ast::Generics,
field_ty: &P<ast::Ty>,
path: &ast::Path,
value: P<ast::Expr>,
) -> P<ast::Expr> {
let where_clause = &generics.where_clause;
let wrapper_generics = builder.from_generics(generics.clone())
.add_lifetime_bound("'__a")
.lifetime_name("'__a")
.build();
let wrapper_ty = builder.path()
.segment("__SerializeWith")
.with_generics(wrapper_generics.clone())
.build()
.build();
quote_expr!(cx, {
struct __SerializeWith $wrapper_generics $where_clause {
value: &'__a $field_ty,
phantom: ::std::marker::PhantomData<$container_ty>,
}
impl $wrapper_generics _serde::ser::Serialize for $wrapper_ty $where_clause {
fn serialize<__S>(&self, __s: &mut __S) -> Result<(), __S::Error>
where __S: _serde::ser::Serializer
{
$path(self.value, __s)
}
}
__SerializeWith {
value: $value,
phantom: ::std::marker::PhantomData::<$container_ty>,
}
})
}

View File

@ -1,5 +1,6 @@
// These just test that serde_codegen is able to produce code that compiles
// successfully when there are a variety of generics involved.
// successfully when there are a variety of generics and non-(de)serializable
// types involved.
extern crate serde;
use self::serde::ser::{Serialize, Serializer};
@ -10,16 +11,16 @@ use self::serde::de::{Deserialize, Deserializer};
#[derive(Serialize, Deserialize)]
struct With<T> {
t: T,
#[serde(serialize_with="ser_i32", deserialize_with="de_i32")]
i: i32,
#[serde(serialize_with="ser_x", deserialize_with="de_x")]
x: X,
}
#[derive(Serialize, Deserialize)]
struct WithRef<'a, T: 'a> {
#[serde(skip_deserializing)]
t: Option<&'a T>,
#[serde(serialize_with="ser_i32", deserialize_with="de_i32")]
i: i32,
#[serde(serialize_with="ser_x", deserialize_with="de_x")]
x: X,
}
#[derive(Serialize, Deserialize)]
@ -40,13 +41,18 @@ struct NoBounds<T> {
#[derive(Serialize, Deserialize)]
enum EnumWith<T> {
A(
#[serde(serialize_with="ser_i32", deserialize_with="de_i32")]
i32),
B {
Unit,
Newtype(
#[serde(serialize_with="ser_x", deserialize_with="de_x")]
X),
Tuple(
T,
#[serde(serialize_with="ser_x", deserialize_with="de_x")]
X),
Struct {
t: T,
#[serde(serialize_with="ser_i32", deserialize_with="de_i32")]
i: i32 },
#[serde(serialize_with="ser_x", deserialize_with="de_x")]
x: X },
}
#[derive(Serialize)]
@ -55,8 +61,23 @@ struct MultipleRef<'a, 'b, 'c, T> where T: 'c, 'c: 'b, 'b: 'a {
rrrt: &'a &'b &'c T,
}
#[derive(Serialize, Deserialize)]
struct Newtype(
#[serde(serialize_with="ser_x", deserialize_with="de_x")]
X
);
#[derive(Serialize, Deserialize)]
struct Tuple<T>(
T,
#[serde(serialize_with="ser_x", deserialize_with="de_x")]
X,
);
//////////////////////////////////////////////////////////////////////////
fn ser_i32<S: Serializer>(_: &i32, _: &mut S) -> Result<(), S::Error> { panic!() }
// Implements neither Serialize nor Deserialize
struct X;
fn ser_x<S: Serializer>(_: &X, _: &mut S) -> Result<(), S::Error> { panic!() }
fn de_x<D: Deserializer>(_: &mut D) -> Result<X, D::Error> { panic!() }
fn de_i32<D: Deserializer>(_: &mut D) -> Result<i32, D::Error> { panic!() }