[vchess.git] / client / src / utils / alea.js

// Random (enough) string for socket and game IDs
export function getRandString()
{
  return (Date.now().toString(36) + Math.random().toString(36).substr(2, 7))
    .toUpperCase();
}

export function randInt(min, max)
{
  if (!max)
  {
    max = min;
    min = 0;
  }
  return Math.floor(Math.random() * (max - min) ) + min;
}

// Inspired by https://github.com/jashkenas/underscore/blob/master/underscore.js
export function sample (arr, n)
{
  n = n || 1;
  let cpArr = arr.map(e => e);
  for (let index = 0; index < n; index++)
  {
    const rand = randInt(index, arr.length);
    const temp = cpArr[index];
    cpArr[index] = cpArr[rand];
    cpArr[rand] = temp;
  }
  return cpArr.slice(0, n);
}

export function shuffle(arr)
{
  return sample(arr, arr.length);
}
Commit	Line	Data
c66a829b BA	1	// Random (enough) string for socket and game IDs
	2	export function getRandString()
	3	{
	4	return (Date.now().toString(36) + Math.random().toString(36).substr(2, 7))
	5	.toUpperCase();
	6	}
	7
656b1878	8	export function randInt(min, max)
c66a829b BA	9	{
	10	if (!max)
	11	{
	12	max = min;
	13	min = 0;
	14	}
	15	return Math.floor(Math.random() * (max - min) ) + min;
	16	}
	17
	18	// Inspired by https://github.com/jashkenas/underscore/blob/master/underscore.js
	19	export function sample (arr, n)
	20	{
	21	n = n \|\| 1;
	22	let cpArr = arr.map(e => e);
	23	for (let index = 0; index < n; index++)
	24	{
656b1878	25	const rand = randInt(index, arr.length);
c66a829b BA	26	const temp = cpArr[index];
	27	cpArr[index] = cpArr[rand];
	28	cpArr[rand] = temp;
	29	}
	30	return cpArr.slice(0, n);
	31	}
	32
	33	export function shuffle(arr)
	34	{
	35	return sample(arr, arr.length);
	36	}