Trait serde::de::MapVisitor
[−]
[src]
pub trait MapVisitor { type Error: Error; fn visit_key_seed<K>(&mut self,
seed: K)
-> Result<Option<K::Value>, Self::Error> where K: DeserializeSeed; fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error> where V: DeserializeSeed; fn visit_seed<K, V>(&mut self,
kseed: K,
vseed: V)
-> Result<Option<(K::Value, V::Value)>, Self::Error> where K: DeserializeSeed, V: DeserializeSeed { ... } fn visit_key<K>(&mut self) -> Result<Option<K>, Self::Error> where K: Deserialize { ... } fn visit_value<V>(&mut self) -> Result<V, Self::Error> where V: Deserialize { ... } fn visit<K, V>(&mut self) -> Result<Option<(K, V)>, Self::Error> where K: Deserialize, V: Deserialize { ... } fn size_hint(&self) -> (usize, Option<usize>) { ... } }
MapVisitor
visits each item in a sequence.
This is a trait that a Deserializer
passes to a Visitor
implementation.
Associated Types
Required Methods
fn visit_key_seed<K>(&mut self,
seed: K)
-> Result<Option<K::Value>, Self::Error> where K: DeserializeSeed
seed: K)
-> Result<Option<K::Value>, Self::Error> where K: DeserializeSeed
This returns Ok(Some(key))
for the next key in the map, or Ok(None)
if there are no more remaining entries.
Deserialize
implementations should typically use
MapVisitor::visit_key
or MapVisitor::visit
instead.
fn visit_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error> where V: DeserializeSeed
This returns a Ok(value)
for the next value in the map.
Deserialize
implementations should typically use
MapVisitor::visit_value
instead.
Provided Methods
fn visit_seed<K, V>(&mut self,
kseed: K,
vseed: V)
-> Result<Option<(K::Value, V::Value)>, Self::Error> where K: DeserializeSeed, V: DeserializeSeed
kseed: K,
vseed: V)
-> Result<Option<(K::Value, V::Value)>, Self::Error> where K: DeserializeSeed, V: DeserializeSeed
This returns Ok(Some((key, value)))
for the next (key-value) pair in
the map, or Ok(None)
if there are no more remaining items.
MapVisitor
implementations should override the default behavior if a
more efficient implementation is possible.
Deserialize
implementations should typically use MapVisitor::visit
instead.
fn visit_key<K>(&mut self) -> Result<Option<K>, Self::Error> where K: Deserialize
This returns Ok(Some(key))
for the next key in the map, or Ok(None)
if there are no more remaining entries.
This method exists as a convenience for Deserialize
implementations.
MapVisitor
implementations should not override the default behavior.
fn visit_value<V>(&mut self) -> Result<V, Self::Error> where V: Deserialize
This returns a Ok(value)
for the next value in the map.
This method exists as a convenience for Deserialize
implementations.
MapVisitor
implementations should not override the default behavior.
fn visit<K, V>(&mut self) -> Result<Option<(K, V)>, Self::Error> where K: Deserialize, V: Deserialize
This returns Ok(Some((key, value)))
for the next (key-value) pair in
the map, or Ok(None)
if there are no more remaining items.
This method exists as a convenience for Deserialize
implementations.
MapVisitor
implementations should not override the default behavior.
fn size_hint(&self) -> (usize, Option<usize>)
Return the lower and upper bound of items remaining in the sequence.
Implementors
impl<I, E> MapVisitor for MapDeserializer<I, E> where I: Iterator,
I::Item: Pair,
I::Item::First: ValueDeserializer<E>,
I::Item::Second: ValueDeserializer<E>,
E: Errorimpl<'a, V_> MapVisitor for &'a mut V_ where V_: MapVisitor