serde_rustler
serde_rustler
provides a Serde Serializer and Deserializer for Rustler types, so you can easily serialize and deserialize native Rust types directly to and from native Elixir terms within your NIFs.
Installation
Install from Crates.io:
[]
= "0.0.2"
API Overview
Below is an example of how you might use serde_rustler
within a rust NIF:
extern crate rustler;
use ;
use ;
use ;
rustler_export_nifs!
// NOTE: to serialize to the correct Elixir record, you MUST tell serde to
// rename the variants to the full Elixir record module atom.
// NOTE: to serialize to an actual Elixir struct (rather than a just map with
// a :__struct__ key), you MUST tell serde to rename the struct to the full
// Elixir struct module atom.
Corresponding Elixir code (code structure, import
s, alias
es and require
s simplified or omitted for brevity):
defmodule SerdeNif do
use Rustler, otp_app: :serde_nif
def readme(_term), do: :erlang.nif_error(:nif_not_loaded)
defmodule Animal do
@type t :: %Animal{
type: Cat.t() | Dog.t(),
name: bitstring,
age: pos_integer,
owner: nil | bitstring
}
defstruct type: Cat.record(), name: "", age: 0, owner: nil
@doc "Deserializes term as a Rust `Animal` struct, then serializes it back into an Elixir `Animal` struct. Should return true."
def test() do
animal = %Animal{
type: Animal.Cat.record(),
name: "Garfield",
age: 41,
}
SerdeNif.readme(animal) == animal
end
end
defmodule AnimalType.Cat do
require Record
@type t {__MODULE__, String.t()}
Record.defrecord(:record, __MODULE__, breed: "tabby")
end
defmodule AnimalType.Dog do
require Record
@type t {__MODULE__, String.t()}
Record.defrecord(:record, :Dog, breed: "mutt")
end
end
Conversion Table
Type Name | Serde (Rust) Values | Elixir Terms (default behaviour) |
---|---|---|
bool | true or false |
true or false |
1 number | i8 , i16 , i32 , i64 , u8 , u16 , u32 , u64 , f32 , f64 (TODO: i128 and u128 ) |
number |
1 char | "" |
bitstring |
string | "" |
bitstring |
2 byte array | &[u8] or Vec<u8> |
<<_::_*8>> |
option | Some(T) or None |
T or :nil |
unit | None |
:nil |
unit struct | struct Unit |
:nil |
3 unit variant | E::A in enum UnitVariant { A } |
:A |
3 newtype struct | struct Millimeters(u8) |
{:Millimeters, u8} |
3 newtype variant | E::N in enum E { N(u8) } |
{:N, u8} |
newtype variant (any Ok and Err tagged enum) |
enum R<T, E> { Ok(T), Err(E) } |
{:ok, T} or {:error, E} |
seq | Vec<T> |
[T] |
tuple | (u8,) |
{u8,} |
3 tuple struct | struct Rgb(u8, u8, u8) |
{:Rgb, u8, u8, u8} |
3 tuple variant | E::T in enum E { T(u8, u8) } |
{:T, u8, u8} |
1 map | HashMap<K, V> |
%{} |
3 struct | struct Rgb { r: u8, g: u8, b: u8 } |
%Rgb{ r: byte, g: byte, b: byte } |
3 struct variant | E::S in enum E { Rgb { r: u8, g: u8, b: u8 } } |
%Rgb{ r: byte, g: byte, b: byte } |
1: API still being decided / implemented.
2: Requires specifying a specific serialize implementation, such as serde_bytes
.
3: When serializing unknown input to terms, atoms will not be created and will instead be replaced with Elixir bitstrings. Therefore "records" will be tuples ({bitstring, ...}
) and "structs" will be maps containing %{:__struct__ => bitstring}
. The unfortunate consequence of this is that deserialize_any
will lack the necessary information needed deserialize many terms without type hints, such as structs
, enums
and enum variants
, and tuples
. (Feedback on how best to solve this is very welcome here).
TODO
- finalize behaviour around chars, charlists, iolists, map keys
- still getting used to Rust, so may need to improve error handling nnd ergnomoics around API
- support for
i128
andu128
- more extensive (i.e. possible addition of smoke, property-based) testing
- benchmarking
Changelog
Version | Change Summary |
---|---|
v0.0.2 | cleanup, better deserialize_any support |
v0.0.1 | initial release |
Contributing
- Fork it https://github.com/your_username/serde_rustler/fork
- Create your feature branch (
git checkout -b feature/fooBar
) - Commit your changes (
git commit -am 'Add some fooBar'
) - Push to the branch (
git push origin feature/fooBar
) - Create a new Pull Request
Maintainers
- Sunny G - @sunny-g
License
MIT