Current File : //var/www/html/node_modules/es-abstract/2021/CodePointAt.js
'use strict';
var GetIntrinsic = require('get-intrinsic');
var $TypeError = GetIntrinsic('%TypeError%');
var callBound = require('call-bind/callBound');
var isLeadingSurrogate = require('../helpers/isLeadingSurrogate');
var isTrailingSurrogate = require('../helpers/isTrailingSurrogate');
var Type = require('./Type');
var UTF16SurrogatePairToCodePoint = require('./UTF16SurrogatePairToCodePoint');
var $charAt = callBound('String.prototype.charAt');
var $charCodeAt = callBound('String.prototype.charCodeAt');
// https://ecma-international.org/ecma-262/12.0/#sec-codepointat
module.exports = function CodePointAt(string, position) {
if (Type(string) !== 'String') {
throw new $TypeError('Assertion failed: `string` must be a String');
}
var size = string.length;
if (position < 0 || position >= size) {
throw new $TypeError('Assertion failed: `position` must be >= 0, and < the length of `string`');
}
var first = $charCodeAt(string, position);
var cp = $charAt(string, position);
var firstIsLeading = isLeadingSurrogate(first);
var firstIsTrailing = isTrailingSurrogate(first);
if (!firstIsLeading && !firstIsTrailing) {
return {
'[[CodePoint]]': cp,
'[[CodeUnitCount]]': 1,
'[[IsUnpairedSurrogate]]': false
};
}
if (firstIsTrailing || (position + 1 === size)) {
return {
'[[CodePoint]]': cp,
'[[CodeUnitCount]]': 1,
'[[IsUnpairedSurrogate]]': true
};
}
var second = $charCodeAt(string, position + 1);
if (!isTrailingSurrogate(second)) {
return {
'[[CodePoint]]': cp,
'[[CodeUnitCount]]': 1,
'[[IsUnpairedSurrogate]]': true
};
}
return {
'[[CodePoint]]': UTF16SurrogatePairToCodePoint(first, second),
'[[CodeUnitCount]]': 2,
'[[IsUnpairedSurrogate]]': false
};
};
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