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:     private static $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:     private static $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 $value A PHP value
45:      *
46:      * @return Boolean True if the value would require double quotes.
47:      */
48:     public static function requiresDoubleQuoting($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 $value A PHP value
57:      *
58:      * @return string The quoted, escaped string
59:      */
60:     public static function escapeWithDoubleQuotes($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 $value A PHP value
69:      *
70:      * @return Boolean True if the value would require single quotes.
71:      */
72:     public static function requiresSingleQuoting($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 $value A PHP value
81:      *
82:      * @return string The quoted, escaped string
83:      */
84:     public static function escapeWithSingleQuotes($value)
85:     {
86:         return sprintf("'%s'", str_replace('\'', '\'\'', $value));
87:     }
88: }
89: