docs: function singletco(partition) {
  
  	var select = function select(compare, a, i, j, k) {
  
  		while (true) {
  
  			if (j - i < 2) return;
  
  			var p = partition(compare, a, i, j);
  
  			if (k < p) j = p;else if (k > p) i = p + 1;else return;
  		}
  	};
  
  	return select;
  }