Taplo
Taplo is a TOML fault-tolerant parser, analyzer and formatter library written in Rust.
It uses Rowan for the syntax tree.
Goals
The main purpose of the library is to provide tools for analyzing TOML data where the layout must be preserved and the original position of every parsed token must be known. Good examples of target applications would be linters, IDE extensions, or language servers.
Even though Taplo exposes a Value that can be serialized with Serde, it should not be used if you are only interested in the actual data. In that case you should probably use one of the mature TOML serializer/deserializer libraries.
Status
The library is pretty much WIP, it has a few bugs that are being fixed, but it is already used in the Even Better TOML Visual Studio Code extension.
The documentation is a bit lacking for now and I'm not planning to put too much effort into it before the library reaches 1.0.0 stable. However the API surface is not too large and should be more or less straightforward to use.
If you need something that is not exposed by the library feel free to open an issue or submit a pull request.
Performance
The lexing is mostly done with Logos, so that should be pretty fast. The overall performance is probably "good enough". There have been no optimization efforts made yet.
Contributing
All kinds of contributions are welcome. As always, please make sure to discuss an issue before you start working on a pull request.