Crate nachricht[−][src]

All encoding functions take &self and a writer and return the amount of written bytes. All decoding functions take a buffer and return Self and the number of consumed bytes.

A note on usize

nachricht internally uses 64 bit unsigned integers to signify field lengths. Rust however uses the architecture-dependent usize for slice indexing. This means that on architectures where usize is smaller than u64 (32 bit i386 for instance), some valid nachricht messages can not be decoded since there would be no way to efficiently index the containers. A DecodeError::Length will be raised in these instances. Likewise, on architectures where usize is larger than u64, some valid Rust datastructures can not be encoded since there is no way to represent them in the wire format. A EncodeError::Length will be raised in these instances.

Examples

use nachricht::*;
use std::borrow::Cow;

let mut buf = Vec::new();
let field = Field { name: Some(Cow::Borrowed("key")), value: Value::Str(Cow::Borrowed("value")) };
Encoder::encode(&field, &mut buf);
assert_eq!(buf, [
    0xc3, // Key of length 3
    0x6b, // 'k'
    0x65, // 'e'
    0x79, // 'y'
    0x85, // Str of length 5
    0x76, // 'v'
    0x61, // 'a'
    0x6c, // 'l'
    0x75, // 'u',
    0x65, // 'e'
]);
let decoded = Decoder::decode(&buf).unwrap();
assert_eq!(field, decoded.0);
assert_eq!(10, decoded.1);

Structs

Decoder

Used to decode nachricht fields. This uses an internal symbol table to allow the decoding of encountered references.

DecoderError
Encoder

Used to encode nachricht fields. This uses an internal symbol table to allow referencing keys and symbols which get repeated.

Field

When encoding struct-like data structures, name should be the identifier of the current field. When encoding sequence-like data, name can be omitted. Note that the type of name is fixed at &str, which means maps with arbitrary key types need to be encoded as sequences.

Enums

DecodeError
EncodeError
Header
Refable
Sign

The sign of an integer. Not that the encoder accepts negative zero but transparently translates it to positive zero. Likewise, decoders will accept the wire format for negative zero (which can only be achieved by purposefully chosing an inefficient encoding) but return positive zero, so that testing the output doesn't need to concern itself with another special case.

Value

The possible values according to the nachricht data model.