LibTest/core/RegExp/Pattern_semantics/firstMatch_DecimalEscape_A01_t03.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion 15.10.2.11: The production DecimalEscape :: DecimalIntegerLiteral
///            [lookahead not in DecimalDigit] evaluates as follows:
///            <ol>
///            <li>Let i be the MV of DecimalIntegerLiteral.</li>
///            <li>If i is zero, return the EscapeValue consisting of a <NUL>
///            character (Unicode value 0000).</li>
///            <li>Return the EscapeValue consisting of the integer i. </li>
///            </ol>
///            NOTE: If \ is followed by a decimal number n whose first digit is
///            not 0, then the escape sequence is considered to be a
///            backreference. It is an error if n is greater than the total
///            number of left capturing parentheses in the entire regular
///            expression. \0 represents the NUL character and cannot be followed
///            by a decimal digit.
/// @description Checks that using a backreference with the number that is
///              greater than the number of left capturing parentheses in the
///              entire regexp causes an error.
/// @3rdparty sputnik-v1:S15.10.2.11_A1_T2.js,S15.10.2.11_A1_T3.js
/// @author rodionov

import "../../../../Utils/expect.dart";
 
main() {
  checkNeg(r"\1");
  checkNeg(r"\2");
  checkNeg(r"\3");
  checkNeg(r"\4");
  checkNeg(r"\10");
  checkNeg(r"\100");
  checkNeg(r"(A)\2", "AA");
}

void checkNeg(String pattern, [String testStr = ""]) {
  bool fail = false;
  RegExp re = new RegExp(pattern);
  Expect.equals(null, re.firstMatch(testStr));
}