export const flatten = <T>(array: T[][]) => (
    array.reduce((flatArray, innerArray) => [
    ...flatArray,
    ...innerArray,
    ], [] as T[])
);

export const getItemsToEitherSideOfArrayIndex = <T>(
    array: T[],
    indexToFindItemsFor: number,
) => (
    array.filter((value, index) => (
        (index + 1) % array.length === indexToFindItemsFor
        ||
        (index - 1 + array.length) % array.length === indexToFindItemsFor
    ))
);

export const getItemAtOppositeSideOfArray = <T>(
    array: T[],
    index: number,
) => array[(index + array.length / 2) % array.length];