1 <?php

     2 

     3 /*

     4  * This file is part of the Symfony package.

     5  * (c) Fabien Potencier <fabien@symfony.com>

     6  *

     7  * For the full copyright and license information, please view the LICENSE

     8  * file that was distributed with this source code.

     9  */

    10 

    11 namespace Symfony\Component\Yaml;

    12 

    13 /**

    14  * Escaper encapsulates escaping rules for single and double-quoted

    15  * YAML strings.

    16  *

    17  * @author Matthew Lewinski <matthew@lewinski.org>

    18  */

    19 class Escaper

    20 {

    21     // Characters that would cause a dumped string to require double quoting.

    22     const REGEX_CHARACTER_TO_ESCAPE = "[\\x00-\\x1f]|\xc2\x85|\xc2\xa0|\xe2\x80\xa8|\xe2\x80\xa9";

    23 

    24     // Mapping arrays for escaping a double quoted string. The backslash is

    25     // first to ensure proper escaping because str_replace operates iteratively

    26     // on the input arrays. This ordering of the characters avoids the use of strtr,

    27     // which performs more slowly.

    28     static private $escapees = array('\\\\', '\\"',

    29                                      "\x00",  "\x01",  "\x02",  "\x03",  "\x04",  "\x05",  "\x06",  "\x07",

    30                                      "\x08",  "\x09",  "\x0a",  "\x0b",  "\x0c",  "\x0d",  "\x0e",  "\x0f",

    31                                      "\x10",  "\x11",  "\x12",  "\x13",  "\x14",  "\x15",  "\x16",  "\x17",

    32                                      "\x18",  "\x19",  "\x1a",  "\x1b",  "\x1c",  "\x1d",  "\x1e",  "\x1f",

    33                                      "\xc2\x85", "\xc2\xa0", "\xe2\x80\xa8", "\xe2\x80\xa9");

    34     static private $escaped  = array('\\"', '\\\\',

    35                                      "\\0",   "\\x01", "\\x02", "\\x03", "\\x04", "\\x05", "\\x06", "\\a",

    36                                      "\\b",   "\\t",   "\\n",   "\\v",   "\\f",   "\\r",   "\\x0e", "\\x0f",

    37                                      "\\x10", "\\x11", "\\x12", "\\x13", "\\x14", "\\x15", "\\x16", "\\x17",

    38                                      "\\x18", "\\x19", "\\x1a", "\\e",   "\\x1c", "\\x1d", "\\x1e", "\\x1f",

    39                                      "\\N", "\\_", "\\L", "\\P");

    40 

    41     /**

    42      * Determines if a PHP value would require double quoting in YAML.

    43      *

    44      * @param string $value A PHP value

    45      *

    46      * @return Boolean True if the value would require double quotes.

    47      */

    48     static public function requiresDoubleQuoting($value)

    49     {

    50         return preg_match('/'.self::REGEX_CHARACTER_TO_ESCAPE.'/u', $value);

    51     }

    52 

    53     /**

    54      * Escapes and surrounds a PHP value with double quotes.

    55      *

    56      * @param string $value A PHP value

    57      *

    58      * @return string The quoted, escaped string

    59      */

    60     static public function escapeWithDoubleQuotes($value)

    61     {

    62         return sprintf('"%s"', str_replace(self::$escapees, self::$escaped, $value));

    63     }

    64 

    65     /**

    66      * Determines if a PHP value would require single quoting in YAML.

    67      *

    68      * @param string $value A PHP value

    69      *

    70      * @return Boolean True if the value would require single quotes.

    71      */

    72     static public function requiresSingleQuoting($value)

    73     {

    74         return preg_match('/[ \s \' " \: \{ \} \[ \] , & \* \# \?] | \A[ - ? | < > = ! % @ ` ]/x', $value);

    75     }

    76 

    77     /**

    78      * Escapes and surrounds a PHP value with single quotes.

    79      *

    80      * @param string $value A PHP value

    81      *

    82      * @return string The quoted, escaped string

    83      */

    84     static public function escapeWithSingleQuotes($value)

    85     {

    86         return sprintf("'%s'", str_replace('\'', '\'\'', $value));

    87     }

    88 }