client/src/utils/alea.js

   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
   8 export function randInt(min, max)
   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   {
  25     const rand = randInt(index, arr.length);
  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 }