Crate erlang_term

Library to convert Erlang External Term Format to Rust objects, without using erlang NIFs.

elixir -e ":erlang.term_to_binary([1,2,3,4]) |> IO.inspect()" | sed -e 's/<</[/g' | sed -e 's/>>/]/g'

Copy that over to rust

use erlang_term::Term;

let input = &[131, 107, 0, 4, 1, 2, 3, 4];
let term = Term::from_bytes(input);
assert_eq!(Ok(Term::Charlist([1, 2, 3, 4].to_vec())), term);

Or if you want more controle over the external term format:

use erlang_term::RawTerm;

let input = &[131, 107, 0, 4, 1, 2, 3, 4];

let term = RawTerm::from_bytes(input);
assert_eq!(Ok(RawTerm::String([1, 2, 3, 4].to_vec())), term);

The Term enum is more what you will find in elixir. The RawTerm enum takes the naming from the external term format spec.

This is already apparent in the above example. In Erlang a string is just a list of characters and in Elixir this is called a Charlist.

In this library I tried to split logic and convertion, so in the RawTerm there is only conversion between binary and rust enum and in the Term there is logic to convert that to a usable interface. Therefore RawTerm to binary is one-to-one and onto. But Term to RawTerm there will be information thrown away.

There is an optional serde feature.

More examples:

use erlang_term::RawTerm;
use std::iter::FromIterator;

let map = RawTerm::Map(vec![
    (RawTerm::SmallAtom(String::from("test")), RawTerm::SmallTuple(vec![RawTerm::SmallAtom(String::from("ok")), RawTerm::SmallInt(15)])),    
    (RawTerm::SmallAtom(String::from("another_key")), RawTerm::Binary(b"this is a string".to_vec())),
    (RawTerm::SmallAtom(String::from("number")), RawTerm::Float(3.1415)),
]);

let binary = vec![
    131, 116, 0, 0, 0, 3, 119, 4, 116, 101, 115, 116, 104, 2, 119, 2, 111, 107, 97, 15, 119, 11, 97, 110, 111, 116, 104, 101, 114, 95, 107, 101, 121, 109, 0, 0, 0, 16, 116, 104, 105, 115, 32, 105, 115, 32, 97, 32, 115, 116, 114, 105, 110, 103, 119, 6, 110, 117, 109, 98, 101, 114, 70, 64, 9, 33, 202, 192, 131, 18, 111
];

assert_eq!(map.to_bytes(), binary);

Re-exports

pub use dump::to_bytes;

pub use parse::from_bytes;

pub use raw_term::RawTerm;

pub use term::Term;

Modules

consts
dump
parse
raw_term
term

Functions

read_binary