Type Alias Intervals

Intervals: [
    start_0: number,
    end_0: number
    | undefined,
    start_i_end_i: (number | undefined)[],
]

represents intervals at which slices should be performed by sliceIntervals.

every even element dictates a start index, which should be:
- a positive number
every odd element dictates the subsequent end index, which can one of:
- a positive number
- a negative number, for reverse indexing
- or undefined, for last element (inclusive) indexing

Example

// mathematically represents the set of intervals: { [0, 10), [20, 30), [90, Inf), [15, arr.length - 15) }
const my_intervals: Intervals = [0, 10, 20, 30, 90, undefined, 15, -15]