A tiny, opinionated text data format and parser (think simple INI with a few extras).

• Comments start with # and run to end-of-line.

• Top-level entries are key: value pairs. Keys are identifiers or quoted strings.

• Values can be: strings (quoted), integers, floats, booleans (true/false), objects { ... }, arrays [ ... ], or tuples (parenthesized, comma-separated values).

• Objects use braces and contain their own key: value lines.

• Arrays use commas to separate elements. Elements may be single values, objects, or tuples.

• Tuples are groups of two-or-more values written in parentheses and separated by commas, e.g. (a, b, c). Inside tuples string tokens may be unquoted identifiers. Tuples are only recognized inside arrays or immediately after a key: on the same line.

Examples:

key: 42
name: "Alice"
coords: [1, 2, 3]
pairs: [("k1", "v1"), ("k2", "v2")]   # array of 2-tuples
triple: (a, b, c)                     # 3-tuple as a value for `triple`

person: {
    name: "Alice"
    age: 30
    tags: [developer, rust]
}

Rationale:

-- The format aims for readability and minimal punctuation. Commas separate array elements; parentheses and commas delimit tuples so identifiers inside tuples don't need quotes.

-- Tuples are explicit: they let you express grouped values (like key/value pairs or fixed arity records) without extra braces; the parentheses make tuple boundaries unambiguous and allow unquoted identifiers inside.

• Using newline/colon boundaries for object entries keeps key/value parsing simple and predictable.