toml

A serde-compatible TOML decoder and encoder for Rust.

For format-preserving edits or finer control over output, see toml_edit

License

This project is licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in toml-rs by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

lib.rs:

A [serde]-compatible [TOML]-parsing library

TOML itself is a simple, ergonomic, and readable configuration format:

[package]
name = "toml"

[dependencies]
serde = "1.0"

The TOML format tends to be relatively common throughout the Rust community for configuration, notably being used by [Cargo], Rust's package manager.

TOML values

A TOML document is represented with the Table type which maps String to the Value enum:

pub enum Value {
    String(String),
    Integer(i64),
    Float(f64),
    Boolean(bool),
    Datetime(Datetime),
    Array(Array),
    Table(Table),
}

Parsing TOML

The easiest way to parse a TOML document is via the Table type:

use toml::Table;

let value = "foo = 'bar'".parse::

assert_eq!(value["foo"].as_str(), Some("bar"));

The [`Table`] type implements a number of convenience methods and
traits; the example above uses [`FromStr`] to parse a [`str`] into a
[`Table`].

## Deserialization and Serialization

This crate supports [`serde`] 1.0 with a number of
implementations of the `Deserialize`, `Serialize`, `Deserializer`, and
`Serializer` traits. Namely, you'll find:

* `Deserialize for Table`
* `Serialize for Table`
* `Deserialize for Value`
* `Serialize for Value`
* `Deserialize for Datetime`
* `Serialize for Datetime`
* `Deserializer for de::Deserializer`
* `Serializer for ser::Serializer`
* `Deserializer for Table`
* `Deserializer for Value`

This means that you can use Serde to deserialize/serialize the
[`Table`] type as well as [`Value`] and [`Datetime`] type in this crate. You can also
use the [`Deserializer`], [`Serializer`], or [`Table`] type itself to act as
a deserializer/serializer for arbitrary types.

An example of deserializing with TOML is:

use serde::Deserialize;

#[derive(Deserialize)]
struct Config {
    ip: String,
    port: Option<u16>,
    keys: Keys,
}

#[derive(Deserialize)]
struct Keys {
    github: String,
    travis: Option<String>,
}

let config: Config = toml::from_str(r#"
    ip = '127.0.0.1'

    [keys]
    github = 'xxxxxxxxxxxxxxxxx'
    travis = 'yyyyyyyyyyyyyyyyy'
"#).unwrap();

assert_eq!(config.ip, "127.0.0.1");
assert_eq!(config.port, None);
assert_eq!(config.keys.github, "xxxxxxxxxxxxxxxxx");
assert_eq!(config.keys.travis.as_ref().unwrap(), "yyyyyyyyyyyyyyyyy");

You can serialize types in a similar fashion:

use serde::Serialize;

#[derive(Serialize)] struct Config { ip: String, port: Option, keys: Keys, }

#[derive(Serialize)] struct Keys { github: String, travis: Option, }

let config = Config { ip: "127.0.0.1".to_string(), port: None, keys: Keys { github: "xxxxxxxxxxxxxxxxx".to_string(), travis: Some("yyyyyyyyyyyyyyyyy".to_string()), }, };

let toml = toml::to_string(&config).unwrap();

[TOML]: https://github.com/toml-lang/toml
[Cargo]: https://crates.io/
[`serde`]: https://serde.rs/
[serde]: https://serde.rs/