GetStringIndex.jsā¢760 B
'use strict';
var callBound = require('call-bound');
var $TypeError = require('es-errors/type');
var isInteger = require('math-intrinsics/isInteger');
var StringToCodePoints = require('./StringToCodePoints');
var $indexOf = callBound('String.prototype.indexOf');
// https://262.ecma-international.org/13.0/#sec-getstringindex
module.exports = function GetStringIndex(S, e) {
if (typeof 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;
};