Tuple Rest Elements
Use rest elements inside tuple types.
Variable-Length Tuples
Tuples normally have a fixed length, but a rest element lets one position absorb any number of items. This models data that is partly fixed and partly variable.
A Trailing Rest Element
Write [string, ...number[]] to mean: one string, then zero or more numbers. The first slot is fixed; the rest grows freely.
type Row = [string, ...number[]]
const r: Row = ["scores", 9, 8, 7]
console.log(r[0], r.length) // scores 4