Spaces:
Configuration error
Configuration error
File size: 1,309 Bytes
5641073 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 |
'use strict';
var GetIntrinsic = require('get-intrinsic');
var Type = require('./Type');
var isInteger = require('../helpers/isInteger');
var isLeadingSurrogate = require('../helpers/isLeadingSurrogate');
var isTrailingSurrogate = require('../helpers/isTrailingSurrogate');
var MAX_SAFE_INTEGER = require('../helpers/maxSafeInteger');
var $TypeError = GetIntrinsic('%TypeError%');
var $charCodeAt = require('call-bind/callBound')('String.prototype.charCodeAt');
// https://262.ecma-international.org/6.0/#sec-advancestringindex
module.exports = function AdvanceStringIndex(S, index, unicode) {
if (Type(S) !== 'String') {
throw new $TypeError('Assertion failed: `S` must be a String');
}
if (!isInteger(index) || index < 0 || index > MAX_SAFE_INTEGER) {
throw new $TypeError('Assertion failed: `length` must be an integer >= 0 and <= 2**53');
}
if (Type(unicode) !== 'Boolean') {
throw new $TypeError('Assertion failed: `unicode` must be a Boolean');
}
if (!unicode) {
return index + 1;
}
var length = S.length;
if ((index + 1) >= length) {
return index + 1;
}
var first = $charCodeAt(S, index);
if (!isLeadingSurrogate(first)) {
return index + 1;
}
var second = $charCodeAt(S, index + 1);
if (!isTrailingSurrogate(second)) {
return index + 1;
}
return index + 2;
};
|