Skip to content
Permalink
9bfb9ba527
Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
Go to file
 
 
Cannot retrieve contributors at this time
31 lines (23 sloc) 842 Bytes
'use strict';
var GetIntrinsic = require('get-intrinsic');
var callBound = require('call-bind/callBound');
var $TypeError = GetIntrinsic('%TypeError%');
var StringToCodePoints = require('./StringToCodePoints');
var Type = require('./Type');
var isInteger = require('../helpers/isInteger');
var $indexOf = callBound('String.prototype.indexOf');
// https://262.ecma-international.org/13.0/#sec-getstringindex
module.exports = function GetStringIndex(S, e) {
if (Type(S) !== 'String') {
throw new $TypeError('Assertion failed: `S` must be a String');
}
if (!isInteger(e) || e < 0) {
throw new $TypeError('Assertion failed: `e` must be a non-negative integer');
}
if (S === '') {
return 0;
}
var codepoints = StringToCodePoints(S);
var eUTF = e >= codepoints.length ? S.length : $indexOf(S, codepoints[e]);
return eUTF;
};