comparison vendor/symfony/yaml/Unescaper.php @ 0:4c8ae668cc8c

Initial import (non-working)
author Chris Cannam
date Wed, 29 Nov 2017 16:09:58 +0000
parents
children 129ea1e6d783
comparison
equal deleted inserted replaced
-1:000000000000 0:4c8ae668cc8c
1 <?php
2
3 /*
4 * This file is part of the Symfony package.
5 *
6 * (c) Fabien Potencier <fabien@symfony.com>
7 *
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
10 */
11
12 namespace Symfony\Component\Yaml;
13
14 use Symfony\Component\Yaml\Exception\ParseException;
15
16 /**
17 * Unescaper encapsulates unescaping rules for single and double-quoted
18 * YAML strings.
19 *
20 * @author Matthew Lewinski <matthew@lewinski.org>
21 *
22 * @internal
23 */
24 class Unescaper
25 {
26 /**
27 * Regex fragment that matches an escaped character in a double quoted string.
28 */
29 const REGEX_ESCAPED_CHARACTER = '\\\\(x[0-9a-fA-F]{2}|u[0-9a-fA-F]{4}|U[0-9a-fA-F]{8}|.)';
30
31 /**
32 * Unescapes a single quoted string.
33 *
34 * @param string $value A single quoted string
35 *
36 * @return string The unescaped string
37 */
38 public function unescapeSingleQuotedString($value)
39 {
40 return str_replace('\'\'', '\'', $value);
41 }
42
43 /**
44 * Unescapes a double quoted string.
45 *
46 * @param string $value A double quoted string
47 *
48 * @return string The unescaped string
49 */
50 public function unescapeDoubleQuotedString($value)
51 {
52 $callback = function ($match) {
53 return $this->unescapeCharacter($match[0]);
54 };
55
56 // evaluate the string
57 return preg_replace_callback('/'.self::REGEX_ESCAPED_CHARACTER.'/u', $callback, $value);
58 }
59
60 /**
61 * Unescapes a character that was found in a double-quoted string.
62 *
63 * @param string $value An escaped character
64 *
65 * @return string The unescaped character
66 */
67 private function unescapeCharacter($value)
68 {
69 switch ($value[1]) {
70 case '0':
71 return "\x0";
72 case 'a':
73 return "\x7";
74 case 'b':
75 return "\x8";
76 case 't':
77 return "\t";
78 case "\t":
79 return "\t";
80 case 'n':
81 return "\n";
82 case 'v':
83 return "\xB";
84 case 'f':
85 return "\xC";
86 case 'r':
87 return "\r";
88 case 'e':
89 return "\x1B";
90 case ' ':
91 return ' ';
92 case '"':
93 return '"';
94 case '/':
95 return '/';
96 case '\\':
97 return '\\';
98 case 'N':
99 // U+0085 NEXT LINE
100 return "\xC2\x85";
101 case '_':
102 // U+00A0 NO-BREAK SPACE
103 return "\xC2\xA0";
104 case 'L':
105 // U+2028 LINE SEPARATOR
106 return "\xE2\x80\xA8";
107 case 'P':
108 // U+2029 PARAGRAPH SEPARATOR
109 return "\xE2\x80\xA9";
110 case 'x':
111 return self::utf8chr(hexdec(substr($value, 2, 2)));
112 case 'u':
113 return self::utf8chr(hexdec(substr($value, 2, 4)));
114 case 'U':
115 return self::utf8chr(hexdec(substr($value, 2, 8)));
116 default:
117 throw new ParseException(sprintf('Found unknown escape character "%s".', $value));
118 }
119 }
120
121 /**
122 * Get the UTF-8 character for the given code point.
123 *
124 * @param int $c The unicode code point
125 *
126 * @return string The corresponding UTF-8 character
127 */
128 private static function utf8chr($c)
129 {
130 if (0x80 > $c %= 0x200000) {
131 return chr($c);
132 }
133 if (0x800 > $c) {
134 return chr(0xC0 | $c >> 6).chr(0x80 | $c & 0x3F);
135 }
136 if (0x10000 > $c) {
137 return chr(0xE0 | $c >> 12).chr(0x80 | $c >> 6 & 0x3F).chr(0x80 | $c & 0x3F);
138 }
139
140 return chr(0xF0 | $c >> 18).chr(0x80 | $c >> 12 & 0x3F).chr(0x80 | $c >> 6 & 0x3F).chr(0x80 | $c & 0x3F);
141 }
142 }