| 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; |
| }; |
| }; |