This crate allows you to parse and modify toml documents, while preserving comments, spaces* and relative order* or items.

*Things it does not preserve:

1. Spaces in headers, e.g. [ ' a ' . b ] will be represented as [' a '.b].
2. Children tables before parent table (tables are reordered, see test).
3. Scattered array of tables (tables are reordered, see test).

toml_edit is primarily tailored for cargo-edit needs.

extern crate toml_edit;

use toml_edit::{Document, value};

fn main() {
    let toml = r#"
"hello" = 'toml!' # comment
['a'.b]
    "#;
    let mut doc = toml.parse::<Document>().expect("invalid doc");
    assert_eq!(doc.to_string(), toml);
    // let's add a new key/value pair inside a.b: c = {d = "hello"}
    doc["a"]["b"]["c"]["d"] = value("hello");
    // autoformat inline table a.b.c: { d = "hello" }
    doc["a"]["b"]["c"].as_inline_table_mut().map(|t| t.fmt());
    let expected = r#"
"hello" = 'toml!' # comment
['a'.b]
c = { d = "hello" }
    "#;
    assert_eq!(doc.to_string(), expected);
}

Licensed under either of

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

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