Not xml
There is no best. It depends on the application
How would it depend?
Some applications don’t have enough config entries to warrant support for nested entries
Some applications need variable-length data, and some even variable-length lists
Some applications don’t care about having fast read/write times or a small memory footprint and can do with more complex formats that require the use of third-party libraries
Some embedded applications (e.g. AVR) don’t have access to a whole lot of libraries
The one already being used by the project.
Yup. If I have to pick one for a new project, I’ll go with TOML unless there’s a reason to pick something else. I like that it’s simple, while also having a bunch of features for when the project grows.
Pretty much same here. With Spring stuff I still use YAML because TOML doesn’t have first class support yet. If TOML is an option I don’t have to go too far out of my way for them I go for it.
YAML has too many foot guns. It’s still less annoying to read and write than JSON though. Properties files are okay but there doesn’t seem to be an agreed upon spec, so for edge cases it can be confusing.
Yup, YAML is a terrible data format, but for a configuration format that you completely control, it works well. Your parser only needs to be good enough to read the configs you create.
Likewise, JSON is a pretty bad config format due to strictness in the syntax (no optional commas, excessive quotes, etc), but it’s pretty good data format because it’s pretty easy to parse.
TOML is like YAML, but it has fewer corner cases so it’s pretty easy to learn completely.
Though anything is superior when it’s already the status quo on a project.
