Function intersperse

packages/cli-v3/src/utilities/ink-table.tsx:362–375

* Intersperses a list of elements with another element.

(intersperser: (index: number) => I, elements: T[])

 * Intersperses a list of elements with another element.
 */
function intersperse<T, I>(intersperser: (index: number) => I, elements: T[]): (T | I)[] {
  // Intersparse by reducing from left.
  const interspersed: (T | I)[] = elements.reduce(
    (acc, element, index) => {
      // Only add element if it's the first one.
      if (acc.length === 0) return [element];
      // Add the intersparser as well otherwise.
      return [...acc, intersperser(index), element];
    },
    [] as (T | I)[]
  );

  return interspersed;
}