Trait serde::ser::Serializer
[−]
[src]
pub trait Serializer { type Error: Error; type SeqState; type TupleState; type TupleStructState; type TupleVariantState; type MapState; type StructState; type StructVariantState; fn serialize_bool(&mut self, v: bool) -> Result<(), Self::Error>; fn serialize_isize(&mut self, v: isize) -> Result<(), Self::Error>; fn serialize_i8(&mut self, v: i8) -> Result<(), Self::Error>; fn serialize_i16(&mut self, v: i16) -> Result<(), Self::Error>; fn serialize_i32(&mut self, v: i32) -> Result<(), Self::Error>; fn serialize_i64(&mut self, v: i64) -> Result<(), Self::Error>; fn serialize_usize(&mut self, v: usize) -> Result<(), Self::Error>; fn serialize_u8(&mut self, v: u8) -> Result<(), Self::Error>; fn serialize_u16(&mut self, v: u16) -> Result<(), Self::Error>; fn serialize_u32(&mut self, v: u32) -> Result<(), Self::Error>; fn serialize_u64(&mut self, v: u64) -> Result<(), Self::Error>; fn serialize_f32(&mut self, v: f32) -> Result<(), Self::Error>; fn serialize_f64(&mut self, v: f64) -> Result<(), Self::Error>; fn serialize_char(&mut self, v: char) -> Result<(), Self::Error>; fn serialize_str(&mut self, value: &str) -> Result<(), Self::Error>; fn serialize_bytes(&mut self, value: &[u8]) -> Result<(), Self::Error>; fn serialize_unit(&mut self) -> Result<(), Self::Error>; fn serialize_unit_struct(
&mut self,
name: &'static str
) -> Result<(), Self::Error>; fn serialize_unit_variant(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str
) -> Result<(), Self::Error>; fn serialize_newtype_struct<T: Serialize>(
&mut self,
name: &'static str,
value: T
) -> Result<(), Self::Error>; fn serialize_newtype_variant<T: Serialize>(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
value: T
) -> Result<(), Self::Error>; fn serialize_none(&mut self) -> Result<(), Self::Error>; fn serialize_some<T: Serialize>(
&mut self,
value: T
) -> Result<(), Self::Error>; fn serialize_seq(
&mut self,
len: Option<usize>
) -> Result<Self::SeqState, Self::Error>; fn serialize_seq_elt<T: Serialize>(
&mut self,
state: &mut Self::SeqState,
value: T
) -> Result<(), Self::Error>; fn serialize_seq_end(
&mut self,
state: Self::SeqState
) -> Result<(), Self::Error>; fn serialize_seq_fixed_size(
&mut self,
size: usize
) -> Result<Self::SeqState, Self::Error>; fn serialize_tuple(
&mut self,
len: usize
) -> Result<Self::TupleState, Self::Error>; fn serialize_tuple_elt<T: Serialize>(
&mut self,
state: &mut Self::TupleState,
value: T
) -> Result<(), Self::Error>; fn serialize_tuple_end(
&mut self,
state: Self::TupleState
) -> Result<(), Self::Error>; fn serialize_tuple_struct(
&mut self,
name: &'static str,
len: usize
) -> Result<Self::TupleStructState, Self::Error>; fn serialize_tuple_struct_elt<T: Serialize>(
&mut self,
state: &mut Self::TupleStructState,
value: T
) -> Result<(), Self::Error>; fn serialize_tuple_struct_end(
&mut self,
state: Self::TupleStructState
) -> Result<(), Self::Error>; fn serialize_tuple_variant(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
len: usize
) -> Result<Self::TupleVariantState, Self::Error>; fn serialize_tuple_variant_elt<T: Serialize>(
&mut self,
state: &mut Self::TupleVariantState,
value: T
) -> Result<(), Self::Error>; fn serialize_tuple_variant_end(
&mut self,
state: Self::TupleVariantState
) -> Result<(), Self::Error>; fn serialize_map(
&mut self,
len: Option<usize>
) -> Result<Self::MapState, Self::Error>; fn serialize_map_key<T: Serialize>(
&mut self,
state: &mut Self::MapState,
key: T
) -> Result<(), Self::Error>; fn serialize_map_value<T: Serialize>(
&mut self,
state: &mut Self::MapState,
value: T
) -> Result<(), Self::Error>; fn serialize_map_end(
&mut self,
state: Self::MapState
) -> Result<(), Self::Error>; fn serialize_struct(
&mut self,
name: &'static str,
len: usize
) -> Result<Self::StructState, Self::Error>; fn serialize_struct_elt<V: Serialize>(
&mut self,
state: &mut Self::StructState,
key: &'static str,
value: V
) -> Result<(), Self::Error>; fn serialize_struct_end(
&mut self,
state: Self::StructState
) -> Result<(), Self::Error>; fn serialize_struct_variant(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
len: usize
) -> Result<Self::StructVariantState, Self::Error>; fn serialize_struct_variant_elt<V: Serialize>(
&mut self,
state: &mut Self::StructVariantState,
key: &'static str,
value: V
) -> Result<(), Self::Error>; fn serialize_struct_variant_end(
&mut self,
state: Self::StructVariantState
) -> Result<(), Self::Error>; }
A trait that describes a type that can serialize a stream of values into the underlying format.
For Serialize
Developers
Non-aggrergate types like integers and strings can be serialized directly by calling the
appropriate function. For Aggregate types there's an initial serialize_T
method that yields
a State object that you should not interact with. For each part of the aggregate there's a
serialize_T_elt
method that allows you to pass values or key/value pairs. The types of the
values or the keys may change between calls, but the serialization format may not necessarily
accept it. The serialize_T_elt
method also takes a mutable reference to the state object.
Make sure that you always use the same state object and only the state object that was returned
by the serialize_T
method. Finally, when your object is done, call the serialize_T_end
method and pass the state object by value
For Serialization Format Developers
If your format has different situations where it accepts different types, create a
Serializer
for each situation. You can create the sub-Serializer
in one of the aggregate
serialize_T
methods and return it as a state object. Remember to also set the corresponding
associated type TState
. In the serialize_T_elt
methods you will be given a mutable
reference to that state. You do not need to do any additional checks for the correctness of the
state object, as it is expected that the user will not modify it. Due to the generic nature
of the Serialize
impls, modifying the object is impossible on stable Rust.
Associated Types
type Error: Error
The error type that can be returned if some error occurs during serialization.
type SeqState
A state object that is initialized by serialize_seq
, passed to
serialize_seq_elt
, and consumed by serialize_seq_end
. Use ()
if no
state is required.
type TupleState
A state object that is initialized by serialize_tuple
, passed to
serialize_tuple_elt
, and consumed by serialize_tuple_end
. Use ()
if no state is required.
type TupleStructState
A state object that is initialized by serialize_tuple_struct
, passed
to serialize_tuple_struct_elt
, and consumed by
serialize_tuple_struct_end
. Use ()
if no state is required.
type TupleVariantState
A state object that is initialized by serialize_tuple_variant
, passed
to serialize_tuple_variant_elt
, and consumed by
serialize_tuple_variant_end
. Use ()
if no state is required.
type MapState
A state object that is initialized by serialize_map
, passed to
serialize_map_elt
, and consumed by serialize_map_end
. Use ()
if no
state is required.
type StructState
A state object that is initialized by serialize_struct
, passed to
serialize_struct_elt
, and consumed by serialize_struct_end
. Use ()
if no state is required.
type StructVariantState
A state object that is initialized by serialize_struct_variant
, passed
to serialize_struct_variant_elt
, and consumed by
serialize_struct_variant_end
. Use ()
if no state is required.
Required Methods
fn serialize_bool(&mut self, v: bool) -> Result<(), Self::Error>
Serializes a bool
value.
fn serialize_isize(&mut self, v: isize) -> Result<(), Self::Error>
Serializes an isize
value. If the format does not differentiate
between isize
and i64
, a reasonable implementation would be to cast
the value to i64
and forward to serialize_i64
.
fn serialize_i8(&mut self, v: i8) -> Result<(), Self::Error>
Serializes an i8
value. If the format does not differentiate between
i8
and i64
, a reasonable implementation would be to cast the value
to i64
and forward to serialize_i64
.
fn serialize_i16(&mut self, v: i16) -> Result<(), Self::Error>
Serializes an i16
value. If the format does not differentiate between
i16
and i64
, a reasonable implementation would be to cast the value
to i64
and forward to serialize_i64
.
fn serialize_i32(&mut self, v: i32) -> Result<(), Self::Error>
Serializes an i32
value. If the format does not differentiate between
i32
and i64
, a reasonable implementation would be to cast the value
to i64
and forward to serialize_i64
.
fn serialize_i64(&mut self, v: i64) -> Result<(), Self::Error>
Serializes an i64
value.
fn serialize_usize(&mut self, v: usize) -> Result<(), Self::Error>
Serializes a usize
value. If the format does not differentiate between
usize
and u64
, a reasonable implementation would be to cast the
value to u64
and forward to serialize_u64
.
fn serialize_u8(&mut self, v: u8) -> Result<(), Self::Error>
Serializes a u8
value. If the format does not differentiate between
u8
and u64
, a reasonable implementation would be to cast the value
to u64
and forward to serialize_u64
.
fn serialize_u16(&mut self, v: u16) -> Result<(), Self::Error>
Serializes a u16
value. If the format does not differentiate between
u16
and u64
, a reasonable implementation would be to cast the value
to u64
and forward to serialize_u64
.
fn serialize_u32(&mut self, v: u32) -> Result<(), Self::Error>
Serializes a u32
value. If the format does not differentiate between
u32
and u64
, a reasonable implementation would be to cast the value
to u64
and forward to serialize_u64
.
fn serialize_u64(&mut self, v: u64) -> Result<(), Self::Error>
Serializes a
u64` value.
fn serialize_f32(&mut self, v: f32) -> Result<(), Self::Error>
Serializes an f32
value. If the format does not differentiate between
f32
and f64
, a reasonable implementation would be to cast the value
to f64
and forward to serialize_f64
.
fn serialize_f64(&mut self, v: f64) -> Result<(), Self::Error>
Serializes an f64
value.
fn serialize_char(&mut self, v: char) -> Result<(), Self::Error>
Serializes a character. If the format does not support characters,
it is reasonable to serialize it as a single element str
or a u32
.
fn serialize_str(&mut self, value: &str) -> Result<(), Self::Error>
Serializes a &str
.
fn serialize_bytes(&mut self, value: &[u8]) -> Result<(), Self::Error>
Enables serializers to serialize byte slices more compactly or more
efficiently than other types of slices. If no efficient implementation
is available, a reasonable implementation would be to forward to
serialize_seq
. If forwarded, the implementation looks usually just like this:
rust let mut state = try!(self.serialize_seq(value)); for b in value { try!(self.serialize_seq_elt(&mut state, b)); } self.serialize_seq_end(state)
fn serialize_unit(&mut self) -> Result<(), Self::Error>
Serializes a ()
value. It's reasonable to just not serialize anything.
fn serialize_unit_struct(
&mut self,
name: &'static str
) -> Result<(), Self::Error>
&mut self,
name: &'static str
) -> Result<(), Self::Error>
Serializes a unit struct value. A reasonable implementation would be to
forward to serialize_unit
.
fn serialize_unit_variant(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str
) -> Result<(), Self::Error>
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str
) -> Result<(), Self::Error>
Serializes a unit variant, otherwise known as a variant with no
arguments. A reasonable implementation would be to forward to
serialize_unit
.
fn serialize_newtype_struct<T: Serialize>(
&mut self,
name: &'static str,
value: T
) -> Result<(), Self::Error>
&mut self,
name: &'static str,
value: T
) -> Result<(), Self::Error>
Allows a tuple struct with a single element, also known as a newtype
struct, to be more efficiently serialized than a tuple struct with
multiple items. A reasonable implementation would be to forward to
serialize_tuple_struct
or to just serialize the inner value without wrapping.
fn serialize_newtype_variant<T: Serialize>(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
value: T
) -> Result<(), Self::Error>
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
value: T
) -> Result<(), Self::Error>
Allows a variant with a single item to be more efficiently serialized
than a variant with multiple items. A reasonable implementation would be
to forward to serialize_tuple_variant
.
fn serialize_none(&mut self) -> Result<(), Self::Error>
Serializes a None
value.
fn serialize_some<T: Serialize>(&mut self, value: T) -> Result<(), Self::Error>
Serializes a Some(...)
value.
fn serialize_seq(
&mut self,
len: Option<usize>
) -> Result<Self::SeqState, Self::Error>
&mut self,
len: Option<usize>
) -> Result<Self::SeqState, Self::Error>
Begins to serialize a sequence. This call must be followed by zero or
more calls to serialize_seq_elt
, then a call to serialize_seq_end
.
fn serialize_seq_elt<T: Serialize>(
&mut self,
state: &mut Self::SeqState,
value: T
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::SeqState,
value: T
) -> Result<(), Self::Error>
Serializes a sequence element. Must have previously called
serialize_seq
.
fn serialize_seq_end(
&mut self,
state: Self::SeqState
) -> Result<(), Self::Error>
&mut self,
state: Self::SeqState
) -> Result<(), Self::Error>
Finishes serializing a sequence.
fn serialize_seq_fixed_size(
&mut self,
size: usize
) -> Result<Self::SeqState, Self::Error>
&mut self,
size: usize
) -> Result<Self::SeqState, Self::Error>
Begins to serialize a sequence whose length will be known at
deserialization time. This call must be followed by zero or more calls
to serialize_seq_elt
, then a call to serialize_seq_end
. A reasonable
implementation would be to forward to serialize_seq
.
fn serialize_tuple(
&mut self,
len: usize
) -> Result<Self::TupleState, Self::Error>
&mut self,
len: usize
) -> Result<Self::TupleState, Self::Error>
Begins to serialize a tuple. This call must be followed by zero or more
calls to serialize_tuple_elt
, then a call to serialize_tuple_end
. A
reasonable implementation would be to forward to serialize_seq
.
fn serialize_tuple_elt<T: Serialize>(
&mut self,
state: &mut Self::TupleState,
value: T
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::TupleState,
value: T
) -> Result<(), Self::Error>
Serializes a tuple element. Must have previously called
serialize_tuple
.
fn serialize_tuple_end(
&mut self,
state: Self::TupleState
) -> Result<(), Self::Error>
&mut self,
state: Self::TupleState
) -> Result<(), Self::Error>
Finishes serializing a tuple.
fn serialize_tuple_struct(
&mut self,
name: &'static str,
len: usize
) -> Result<Self::TupleStructState, Self::Error>
&mut self,
name: &'static str,
len: usize
) -> Result<Self::TupleStructState, Self::Error>
Begins to serialize a tuple struct. This call must be followed by zero
or more calls to serialize_tuple_struct_elt
, then a call to
serialize_tuple_struct_end
. A reasonable implementation would be to
forward to serialize_tuple
.
fn serialize_tuple_struct_elt<T: Serialize>(
&mut self,
state: &mut Self::TupleStructState,
value: T
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::TupleStructState,
value: T
) -> Result<(), Self::Error>
Serializes a tuple struct element. Must have previously called
serialize_tuple_struct
.
fn serialize_tuple_struct_end(
&mut self,
state: Self::TupleStructState
) -> Result<(), Self::Error>
&mut self,
state: Self::TupleStructState
) -> Result<(), Self::Error>
Finishes serializing a tuple struct.
fn serialize_tuple_variant(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
len: usize
) -> Result<Self::TupleVariantState, Self::Error>
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
len: usize
) -> Result<Self::TupleVariantState, Self::Error>
Begins to serialize a tuple variant. This call must be followed by zero
or more calls to serialize_tuple_variant_elt
, then a call to
serialize_tuple_variant_end
. A reasonable implementation would be to
forward to serialize_tuple_struct
.
fn serialize_tuple_variant_elt<T: Serialize>(
&mut self,
state: &mut Self::TupleVariantState,
value: T
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::TupleVariantState,
value: T
) -> Result<(), Self::Error>
Serializes a tuple variant element. Must have previously called
serialize_tuple_variant
.
fn serialize_tuple_variant_end(
&mut self,
state: Self::TupleVariantState
) -> Result<(), Self::Error>
&mut self,
state: Self::TupleVariantState
) -> Result<(), Self::Error>
Finishes serializing a tuple variant.
fn serialize_map(
&mut self,
len: Option<usize>
) -> Result<Self::MapState, Self::Error>
&mut self,
len: Option<usize>
) -> Result<Self::MapState, Self::Error>
Begins to serialize a map. This call must be followed by zero or more
calls to serialize_map_key
and serialize_map_value
, then a call to
serialize_map_end
.
fn serialize_map_key<T: Serialize>(
&mut self,
state: &mut Self::MapState,
key: T
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::MapState,
key: T
) -> Result<(), Self::Error>
Serialize a map key. Must have previously called serialize_map
.
fn serialize_map_value<T: Serialize>(
&mut self,
state: &mut Self::MapState,
value: T
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::MapState,
value: T
) -> Result<(), Self::Error>
Serialize a map value. Must have previously called serialize_map
.
fn serialize_map_end(
&mut self,
state: Self::MapState
) -> Result<(), Self::Error>
&mut self,
state: Self::MapState
) -> Result<(), Self::Error>
Finishes serializing a map.
fn serialize_struct(
&mut self,
name: &'static str,
len: usize
) -> Result<Self::StructState, Self::Error>
&mut self,
name: &'static str,
len: usize
) -> Result<Self::StructState, Self::Error>
Begins to serialize a struct. This call must be followed by zero or more
calls to serialize_struct_elt
, then a call to serialize_struct_end
.
fn serialize_struct_elt<V: Serialize>(
&mut self,
state: &mut Self::StructState,
key: &'static str,
value: V
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::StructState,
key: &'static str,
value: V
) -> Result<(), Self::Error>
Serializes a struct field. Must have previously called
serialize_struct
.
fn serialize_struct_end(
&mut self,
state: Self::StructState
) -> Result<(), Self::Error>
&mut self,
state: Self::StructState
) -> Result<(), Self::Error>
Finishes serializing a struct.
fn serialize_struct_variant(
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
len: usize
) -> Result<Self::StructVariantState, Self::Error>
&mut self,
name: &'static str,
variant_index: usize,
variant: &'static str,
len: usize
) -> Result<Self::StructVariantState, Self::Error>
Begins to serialize a struct variant. This call must be followed by zero
or more calls to serialize_struct_variant_elt
, then a call to
serialize_struct_variant_end
.
fn serialize_struct_variant_elt<V: Serialize>(
&mut self,
state: &mut Self::StructVariantState,
key: &'static str,
value: V
) -> Result<(), Self::Error>
&mut self,
state: &mut Self::StructVariantState,
key: &'static str,
value: V
) -> Result<(), Self::Error>
Serialize a struct variant element. Must have previously called
serialize_struct_variant
.
fn serialize_struct_variant_end(
&mut self,
state: Self::StructVariantState
) -> Result<(), Self::Error>
&mut self,
state: Self::StructVariantState
) -> Result<(), Self::Error>
Finishes serializing a struct variant.