blob: ecc0d21cb1cc150a92dc2d2d5905f8e451dddd71 [file] [log] [blame]
var toInteger = require('./_to-integer')
, defined = require('./_defined');
// true -> String#at
// false -> String#codePointAt
module.exports = function(TO_STRING){
return function(that, pos){
var s = String(defined(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;
};
};