Trait serde::de::MapVisitor

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>) { ... }
}

[−] Expand description

MapVisitor visits each item in a sequence.

This is a trait that a Deserializer passes to a Visitor implementation.

Associated Types

type Error: Error[−]

The error type that can be returned if some error occurs during deserialization.

Required Methods

fn visit_key_seed<K>(&mut self,
                     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[−]

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: Error
• impl<'a, V_> MapVisitor for &'a mut V_ where V_: MapVisitor