Kohana v3.3.0

vendor/symfony/yaml/Symfony/Component/Yaml/Unescaper.php

@@ -0,0 +1,145 @@
+<?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\Yaml;
+
+/**
+ * Unescaper encapsulates unescaping rules for single and double-quoted
+ * YAML strings.
+ *
+ * @author Matthew Lewinski <matthew@lewinski.org>
+ */
+class Unescaper
+{
+    // Parser and Inline assume UTF-8 encoding, so escaped Unicode characters
+    // must be converted to that encoding.
+    const ENCODING = 'UTF-8';
+
+    // Regex fragment that matches an escaped character in a double quoted
+    // string.
+    const REGEX_ESCAPED_CHARACTER = "\\\\([0abt\tnvfre \\\"\\/\\\\N_LP]|x[0-9a-fA-F]{2}|u[0-9a-fA-F]{4}|U[0-9a-fA-F]{8})";
+
+    /**
+     * Unescapes a single quoted string.
+     *
+     * @param string $value A single quoted string.
+     *
+     * @return string The unescaped string.
+     */
+    public function unescapeSingleQuotedString($value)
+    {
+        return str_replace('\'\'', '\'', $value);
+    }
+
+    /**
+     * Unescapes a double quoted string.
+     *
+     * @param string $value A double quoted string.
+     *
+     * @return string The unescaped string.
+     */
+    public function unescapeDoubleQuotedString($value)
+    {
+        $self = $this;
+        $callback = function($match) use ($self) {
+            return $self->unescapeCharacter($match[0]);
+        };
+
+        // evaluate the string
+        return preg_replace_callback('/'.self::REGEX_ESCAPED_CHARACTER.'/u', $callback, $value);
+    }
+
+    /**
+     * Unescapes a character that was found in a double-quoted string
+     *
+     * @param string $value An escaped character
+     *
+     * @return string The unescaped character
+     */
+    public function unescapeCharacter($value)
+    {
+        switch ($value{1}) {
+            case '0':
+                return "\x0";
+            case 'a':
+                return "\x7";
+            case 'b':
+                return "\x8";
+            case 't':
+                return "\t";
+            case "\t":
+                return "\t";
+            case 'n':
+                return "\n";
+            case 'v':
+                return "\xb";
+            case 'f':
+                return "\xc";
+            case 'r':
+                return "\xd";
+            case 'e':
+                return "\x1b";
+            case ' ':
+                return ' ';
+            case '"':
+                return '"';
+            case '/':
+                return '/';
+            case '\\':
+                return '\\';
+            case 'N':
+                // U+0085 NEXT LINE
+                return $this->convertEncoding("\x00\x85", self::ENCODING, 'UCS-2BE');
+            case '_':
+                // U+00A0 NO-BREAK SPACE
+                return $this->convertEncoding("\x00\xA0", self::ENCODING, 'UCS-2BE');
+            case 'L':
+                // U+2028 LINE SEPARATOR
+                return $this->convertEncoding("\x20\x28", self::ENCODING, 'UCS-2BE');
+            case 'P':
+                // U+2029 PARAGRAPH SEPARATOR
+                return $this->convertEncoding("\x20\x29", self::ENCODING, 'UCS-2BE');
+            case 'x':
+                $char = pack('n', hexdec(substr($value, 2, 2)));
+
+                return $this->convertEncoding($char, self::ENCODING, 'UCS-2BE');
+            case 'u':
+                $char = pack('n', hexdec(substr($value, 2, 4)));
+
+                return $this->convertEncoding($char, self::ENCODING, 'UCS-2BE');
+            case 'U':
+                $char = pack('N', hexdec(substr($value, 2, 8)));
+
+                return $this->convertEncoding($char, self::ENCODING, 'UCS-4BE');
+        }
+    }
+
+    /**
+     * Convert a string from one encoding to another.
+     *
+     * @param string $value The string to convert
+     * @param string $to    The input encoding
+     * @param string $from  The output encoding
+     *
+     * @return string The string with the new encoding
+     *
+     * @throws \RuntimeException if no suitable encoding function is found (iconv or mbstring)
+     */
+    private function convertEncoding($value, $to, $from)
+    {
+        if (function_exists('mb_convert_encoding')) {
+            return mb_convert_encoding($value, $to, $from);
+        } elseif (function_exists('iconv')) {
+            return iconv($from, $to, $value);
+        }
+
+        throw new \RuntimeException('No suitable convert encoding function (install the iconv or mbstring extension).');
+    }
+}