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.

/// @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));
}