/**
 * Fisher-Yates shuffle algorithm, based on these answers:
 * https://stackoverflow.com/questions/6274339/how-can-i-shuffle-an-array
 */
export function shuffle<T>(arr: T[]): T[] {
    let ret = [...arr];
    for (let i = ret.length - 1; i >= 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        if (i === j) continue;
        const x = ret[i]!;
        ret[i] = ret[j]!;
        ret[j] = x;
    }
    return ret;
}