32 lines
917 B
JavaScript
32 lines
917 B
JavaScript
'use strict';
|
|
|
|
var CodePointAt = require('./CodePointAt');
|
|
|
|
var isInteger = require('../helpers/isInteger');
|
|
var MAX_SAFE_INTEGER = require('../helpers/maxSafeInteger');
|
|
|
|
var $TypeError = require('es-errors/type');
|
|
|
|
// https://262.ecma-international.org/11.0/#sec-advancestringindex
|
|
|
|
module.exports = function AdvanceStringIndex(S, index, unicode) {
|
|
if (typeof 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 (typeof 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 cp = CodePointAt(S, index);
|
|
return index + cp['[[CodeUnitCount]]'];
|
|
};
|