Struct OneOrMany 

pub struct OneOrMany<A = Same, F = PreferOne>(/* private fields */);

A collection that also accepts a single element.

When deserializing, a sequence is the collection and every other value (an atom or a map) is a single element, which becomes a collection of one. The elements are deserialized with the adapter A (by default Same). This is for data that writes a list with one element as the element itself ("tags": "a" and "tags": ["a", "b"]). As a sequence is always the collection, elements cannot be sequences themselves.

When serializing, F decides the form: PreferOne (the default) writes a collection with exactly one element as that element and PreferMany always writes a sequence.

Supported are Vec<T>, VecDeque<T>, BTreeSet<T> and HashSet<T>.

use deser::adapters::{OneOrMany, PreferMany};
use deser::{Deserialize, Serialize};

#[derive(Serialize, Deserialize, Debug, PartialEq)]
pub struct Rule {
    #[deser(as = OneOrMany)]
    hosts: Vec<String>,
    #[deser(as = OneOrMany<_, PreferMany>)]
    ports: Vec<u16>,
}

let rule: Rule = deser_json::from_str(r#"{"hosts": "a", "ports": 80}"#).unwrap();
assert_eq!(rule.hosts, ["a"]);
assert_eq!(rule.ports, [80]);
assert_eq!(
    deser_json::to_string(&rule).unwrap(),
    r#"{"hosts":"a","ports":[80]}"#
);

In formats where keys can be given more than once (like query strings, see ContainerShape::set_multimap) the values of all occurrences of the key are collected, as without the adapter.

Trait Implementations

impl<'de, T: Ord + Send, A: Deserialize<'de, T>, F: OneOrManyForm> Deserialize<'de, BTreeSet<T>> for OneOrMany<A, F>

fn deserialize_into<'out>( out: &'out mut Option<BTreeSet<T>>, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that deserializes the value into the given slot.

fn expecting() -> Cow<'static, str>

Returns what the value expects, for error messages.

fn initial_value() -> Option<BTreeSet<T>>

Provides the value of a missing struct field.

fn deserialize_atom( slot: &mut Slot<T, Self>, atom: Atom<'_>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom into the slot.

fn deserialize_borrowed_atom( slot: &mut Slot<T, Self>, atom: Atom<'de>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom that borrows from the data being deserialized into the slot.

fn describe_type(d: &mut dyn Describe)

Describes the Rust shape of the type.

fn deserialize_update<'out>( value: &'out mut T, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that updates an existing value.

impl<'de, T: Hash + Eq + Send, H: BuildHasher + Default + Send, A: Deserialize<'de, T>, F: OneOrManyForm> Deserialize<'de, HashSet<T, H>> for OneOrMany<A, F>

fn deserialize_into<'out>( out: &'out mut Option<HashSet<T, H>>, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that deserializes the value into the given slot.

fn expecting() -> Cow<'static, str>

Returns what the value expects, for error messages.

fn initial_value() -> Option<HashSet<T, H>>

Provides the value of a missing struct field.

fn deserialize_atom( slot: &mut Slot<T, Self>, atom: Atom<'_>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom into the slot.

fn deserialize_borrowed_atom( slot: &mut Slot<T, Self>, atom: Atom<'de>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom that borrows from the data being deserialized into the slot.

fn describe_type(d: &mut dyn Describe)

Describes the Rust shape of the type.

fn deserialize_update<'out>( value: &'out mut T, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that updates an existing value.

impl<'de, T: Send, A: Deserialize<'de, T>, F: OneOrManyForm> Deserialize<'de, Vec<T>> for OneOrMany<A, F>

fn deserialize_into<'out>( out: &'out mut Option<Vec<T>>, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that deserializes the value into the given slot.

fn expecting() -> Cow<'static, str>

Returns what the value expects, for error messages.

fn initial_value() -> Option<Vec<T>>

Provides the value of a missing struct field.

fn deserialize_atom( slot: &mut Slot<T, Self>, atom: Atom<'_>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom into the slot.

fn deserialize_borrowed_atom( slot: &mut Slot<T, Self>, atom: Atom<'de>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom that borrows from the data being deserialized into the slot.

fn describe_type(d: &mut dyn Describe)

Describes the Rust shape of the type.

fn deserialize_update<'out>( value: &'out mut T, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that updates an existing value.

impl<'de, T: Send, A: Deserialize<'de, T>, F: OneOrManyForm> Deserialize<'de, VecDeque<T>> for OneOrMany<A, F>

fn deserialize_into<'out>( out: &'out mut Option<VecDeque<T>>, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that deserializes the value into the given slot.

fn expecting() -> Cow<'static, str>

Returns what the value expects, for error messages.

fn initial_value() -> Option<VecDeque<T>>

Provides the value of a missing struct field.

fn deserialize_atom( slot: &mut Slot<T, Self>, atom: Atom<'_>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom into the slot.

fn deserialize_borrowed_atom( slot: &mut Slot<T, Self>, atom: Atom<'de>, state: &mut State, ) -> Result<(), Error>

Deserializes an atom that borrows from the data being deserialized into the slot.

fn describe_type(d: &mut dyn Describe)

Describes the Rust shape of the type.

fn deserialize_update<'out>( value: &'out mut T, state: &mut State, ) -> SinkHandle<'out, 'de>

Creates a sink that updates an existing value.

impl<T: Sync, A: Serialize<T>, F: OneOrManyForm> Serialize<BTreeSet<T>> for OneOrMany<A, F>

fn serialize<'a>( value: &'a BTreeSet<T>, _state: &mut State, ) -> Result<Emit<'a>, Error>

Serializes the value.

fn describe(value: &BTreeSet<T>, d: &mut dyn Describe)

Describes the Rust shape of the value.

fn finish(value: &T, state: &mut State) -> Result<(), Error>

Invoked after the serialization finished.

fn is_optional(value: &T) -> bool

Checks if the value represents an optional value.

fn container_shape(value: &T) -> ContainerShape

Returns the shape of the value if it’s a map or sequence.

impl<T: Sync, H: BuildHasher + Sync, A: Serialize<T>, F: OneOrManyForm> Serialize<HashSet<T, H>> for OneOrMany<A, F>

fn serialize<'a>( value: &'a HashSet<T, H>, _state: &mut State, ) -> Result<Emit<'a>, Error>

Serializes the value.

fn describe(value: &HashSet<T, H>, d: &mut dyn Describe)

Describes the Rust shape of the value.

fn finish(value: &T, state: &mut State) -> Result<(), Error>

Invoked after the serialization finished.

fn is_optional(value: &T) -> bool

Checks if the value represents an optional value.

fn container_shape(value: &T) -> ContainerShape

Returns the shape of the value if it’s a map or sequence.

impl<T: Sync, A: Serialize<T>, F: OneOrManyForm> Serialize<Vec<T>> for OneOrMany<A, F>

fn serialize<'a>( value: &'a Vec<T>, _state: &mut State, ) -> Result<Emit<'a>, Error>

Serializes the value.

fn describe(value: &Vec<T>, d: &mut dyn Describe)

Describes the Rust shape of the value.

fn finish(value: &T, state: &mut State) -> Result<(), Error>

Invoked after the serialization finished.

fn is_optional(value: &T) -> bool

Checks if the value represents an optional value.

fn container_shape(value: &T) -> ContainerShape

Returns the shape of the value if it’s a map or sequence.

impl<T: Sync, A: Serialize<T>, F: OneOrManyForm> Serialize<VecDeque<T>> for OneOrMany<A, F>

fn serialize<'a>( value: &'a VecDeque<T>, _state: &mut State, ) -> Result<Emit<'a>, Error>

Serializes the value.

fn describe(value: &VecDeque<T>, d: &mut dyn Describe)

Describes the Rust shape of the value.

fn finish(value: &T, state: &mut State) -> Result<(), Error>

Invoked after the serialization finished.

fn is_optional(value: &T) -> bool

Checks if the value represents an optional value.

fn container_shape(value: &T) -> ContainerShape

Returns the shape of the value if it’s a map or sequence.