group.js

gistfile1.js

  var group = function(arr, cb, ctx) {
    var buckets = [];
    for (var i=0, len=arr.length; i<len; i++) {
      if (cb.call(ctx, arr[i], i) || !buckets.length) {
        buckets.push([arr[i]]);
      } else {
        buckets[buckets.length-1].push(arr[i]);
      }
    }
    return buckets;
  };