/* */ 
var $ = require("./$");
module.exports = function(TO_STRING) {
  return function(that, pos) {
    var s = String($.assertDefined(that)),
        i = $.toInteger(pos),
        l = s.length,
        a,
        b;
    if (i < 0 || i >= l)
      return TO_STRING ? '' : undefined;
    a = s.charCodeAt(i);
    return a < 0xd800 || a > 0xdbff || i + 1 === l || (b = s.charCodeAt(i + 1)) < 0xdc00 || b > 0xdfff ? TO_STRING ? s.charAt(i) : a : TO_STRING ? s.slice(i, i + 2) : (a - 0xd800 << 10) + (b - 0xdc00) + 0x10000;
  };
};