<?php
 
 /*
  * This file is part of the Symfony package.
  *
  * (c) Fabien Potencier <fabien@symfony.com>
  *
  * For the full copyright and license information, please view the LICENSE
  * file that was distributed with this source code.
  */
 
 namespace Symfony\Component\Translation\Extractor;
 
 /*
  * The following is derived from code at http://github.com/nikic/PHP-Parser
  *
  * Copyright (c) 2011 by Nikita Popov
  *
  * Some rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  *       notice, this list of conditions and the following disclaimer.
  *
  *     * Redistributions in binary form must reproduce the above
  *       copyright notice, this list of conditions and the following
  *       disclaimer in the documentation and/or other materials provided
  *       with the distribution.
  *
  *     * The names of the contributors may not be used to endorse or
  *       promote products derived from this software without specific
  *       prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 class PhpStringTokenParser
 {
     protected static $replacements = [
         '\\' => '\\',
         '$' => '$',
         'n' => "\n",
         'r' => "\r",
         't' => "\t",
         'f' => "\f",
         'v' => "\v",
         'e' => "\x1B",
     ];
 
     /**
      * Parses a string token.
      *
      * @param string $str String token content
      *
      * @return string The parsed string
      */
     public static function parse($str)
     {
         $bLength = 0;
         if ('b' === $str[0]) {
             $bLength = 1;
         }
 
         if ('\'' === $str[$bLength]) {
             return str_replace(
                 ['\\\\', '\\\''],
                 ['\\', '\''],
                 substr($str, $bLength + 1, -1)
             );
         } else {
             return self::parseEscapeSequences(substr($str, $bLength + 1, -1), '"');
         }
     }
 
     /**
      * Parses escape sequences in strings (all string types apart from single quoted).
      *
      * @param string      $str   String without quotes
      * @param string|null $quote Quote type
      *
      * @return string String with escape sequences parsed
      */
     public static function parseEscapeSequences($str, $quote)
     {
         if (null !== $quote) {
             $str = str_replace('\\'.$quote, $quote, $str);
         }
 
         return preg_replace_callback(
             '~\\\\([\\\\$nrtfve]|[xX][0-9a-fA-F]{1,2}|[0-7]{1,3})~',
             [__CLASS__, 'parseCallback'],
             $str
         );
     }
 
     private static function parseCallback($matches)
     {
         $str = $matches[1];
 
         if (isset(self::$replacements[$str])) {
             return self::$replacements[$str];
         } elseif ('x' === $str[0] || 'X' === $str[0]) {
             return \chr(hexdec($str));
         } else {
             return \chr(octdec($str));
         }
     }
 
     /**
      * Parses a constant doc string.
      *
      * @param string $startToken Doc string start token content (<<<SMTHG)
      * @param string $str        String token content
      *
      * @return string Parsed string
      */
     public static function parseDocString($startToken, $str)
     {
         // strip last newline (thanks tokenizer for sticking it into the string!)
         $str = preg_replace('~(\r\n|\n|\r)$~', '', $str);
 
         // nowdoc string
         if (false !== strpos($startToken, '\'')) {
             return $str;
         }
 
         return self::parseEscapeSequences($str, null);
     }
 }