Trait rustc_serialize::DecoderHelpers [−] [src]

pub trait DecoderHelpers: Decoder {
    fn read_to_vec<T, F>(&mut self, f: F) -> Result<Vec<T>, Self::Error>
    where
        F: FnMut(&mut Self) -> Result<T, Self::Error>;
}

Trait with helper functions for implementing Decodable.

This trait is implemented for everything that implements Decoder. Decodable implementations can make use of it to make their implementations easier.

Required Methods

Read a sequence into a vector.

Storing sequences as vectors is a common pattern. This method makes deserializing such sequences easier by wrapping the calls to Decoder::read_seq and Decoder::read_seq_elt.

Examples

use rustc_serialize::Decodable;
use rustc_serialize::Decoder;
use rustc_serialize::DecoderHelpers;

struct NumberSequence {
    elements: Vec<i32>,
}

impl Decodable for NumberSequence {
    fn decode<D: Decoder>(d: &mut D) -> Result<NumberSequence, D::Error> {
        d.read_struct("NumberSequence", 2, |d| {
            Ok(NumberSequence{
                elements: try!(d.read_struct_field("elements", 0, |d| {
                    d.read_to_vec(|d| { d.read_i32() })
                }))
            })
        })
    }
}

Implementors