source: imaps-frontend/node_modules/es-abstract/2022/GetStringIndex.js@ 79a0317

'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;
};