Trait Serializer

Source

pub trait Serializer {
    // Required method
    fn drive(&mut self, driver: &mut SerializeDriver<'_>) -> Result<(), Error>;

    // Provided methods
    fn serialize<T: Serialize + ?Sized>(
        &mut self,
        value: &T,
    ) -> Result<(), Error>
       where Self: Sized { ... }
    fn serialize_with<T, F>(&mut self, value: &T, setup: F) -> Result<(), Error>
       where T: Serialize + ?Sized,
             F: FnOnce(&mut SerializeDriver<'_>),
             Self: Sized { ... }
    fn serialize_ref(&mut self, value: SerializeRef<'_>) -> Result<(), Error> { ... }
}

Expand description

Serializes values into an output.

This is implemented by the serializers of the data formats (for instance deser_json::Serializer) and by other destinations of values (like the value type of deser-value). A serializer holds its output, every call serializes a value into it. Serializers implement drive which receives the events of a value from a driver. The provided methods create the driver:

serialize serializes a value.
serialize_with serializes a value and allows configuring the driver first, for instance to add Layers.

use deser::ser::{SerializeDriver, Serializer};
use deser::{Atom, Error, ErrorKind, Event};

/// A format which writes sequences of numbers comma separated.
struct Numbers(String);

impl Serializer for Numbers {
    fn drive(
        &mut self,
        driver: &mut SerializeDriver<'_>,
    ) -> Result<(), Error> {
        driver.drive(|event, _state| {
            match event {
                Event::Atom(Atom::U64(value)) => {
                    if !self.0.is_empty() {
                        self.0.push_str(", ");
                    }
                    self.0.push_str(&value.to_string());
                }
                Event::SeqStart(_) | Event::SeqEnd => {}
                _ => {
                    return Err(Error::new(
                        ErrorKind::UnsupportedType,
                        "not a number",
                    ));
                }
            }
            Ok(())
        })
    }
}

let mut numbers = Numbers(String::new());
numbers.serialize(&vec![1u64, 2, 3]).unwrap();
assert_eq!(numbers.0, "1, 2, 3");