Expand description

Apply singleton_map to all enums contained within the data structure.

§Example

use serde::{Deserialize, Serialize};

#[derive(Serialize, Deserialize, PartialEq, Debug)]
enum Enum {
    Int(i32),
}

#[derive(Serialize, Deserialize, PartialEq, Debug)]
struct Inner {
    a: Enum,
    bs: Vec<Enum>,
}

#[derive(Serialize, Deserialize, PartialEq, Debug)]
struct Outer {
    tagged_style: Inner,

    #[serde(with = "serde_yaml::with::singleton_map_recursive")]
    singleton_map_style: Inner,
}

fn main() {
    let object = Outer {
        tagged_style: Inner {
            a: Enum::Int(0),
            bs: vec![Enum::Int(1)],
        },
        singleton_map_style: Inner {
            a: Enum::Int(2),
            bs: vec![Enum::Int(3)],
        },
    };

    let yaml = serde_yaml::to_string(&object).unwrap();
    print!("{}", yaml);

    let deserialized: Outer = serde_yaml::from_str(&yaml).unwrap();
    assert_eq!(object, deserialized);
}

The serialized output is:

tagged_style:
  a: !Int 0
  bs:
  - !Int 1
singleton_map_style:
  a:
    Int: 2
  bs:
  - Int: 3

This module can also be used for the top-level serializer or deserializer call, without serde(with = …), as follows.

use std::io::{self, Write};

fn main() {
    let object = Inner {
        a: Enum::Int(0),
        bs: vec![Enum::Int(1)],
    };

    let mut buf = Vec::new();
    let mut serializer = serde_yaml::Serializer::new(&mut buf);
    serde_yaml::with::singleton_map_recursive::serialize(&object, &mut serializer).unwrap();
    io::stdout().write_all(&buf).unwrap();

    let deserializer = serde_yaml::Deserializer::from_slice(&buf);
    let deserialized: Inner = serde_yaml::with::singleton_map_recursive::deserialize(deserializer).unwrap();
    assert_eq!(object, deserialized);
}

Functions§