// Copyright 2019 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. namespace string { // ES6 #sec-string.prototype.substring transitioning javascript builtin StringPrototypeSubstring( js-implicit context: NativeContext, receiver: JSAny)(...arguments): String { // Check that {receiver} is coercible to Object and convert it to a String. const string: String = ToThisString(receiver, 'String.prototype.substring'); const length: uintptr = string.length_uintptr; // Conversion and bounds-checks for {start}. const arg0 = arguments[0]; let start: uintptr = arg0 != Undefined ? ClampToIndexRange(arg0, length) : 0; // Conversion and bounds-checks for {end}. const arg1 = arguments[1]; let end: uintptr = arg1 != Undefined ? ClampToIndexRange(arg1, length) : length; if (end < start) { const tmp: uintptr = end; end = start; start = tmp; } return SubString(string, start, end); } }