TOML has the inline table syntax with curlies, like JSON, and inline array syntax with brackets, also like JSON. It could support nesting pretty well. Sadly, i

TOML has the inline table syntax with curlies, like JSON, and inline array syntax with brackets, also like JSON. It could support nesting pretty well. Sadly, it doesn't support line breaks in the inline table syntax, so using inline tables for nesting is a PITA; inline tables are pretty much unusable for anything which doesn't fit within like 80-100 characters. Inline arrays can contain newlines however, so deeply nested arrays works well. Newlines in inline tables will be coming in TOML 1.1, which will make TOML much better for deeply nested structures. Unfortunately, there will probably be many years until 1.1 is both actually released and well supported across the ecosystem. And of course, inline tables can't be at the top level of the document, so TOML might still not be the best way to represent a single deelpy nested structure.