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[yaffs-website] / vendor / drush / drush / internal-copy / Config / Yaml / Unescaper.php
diff --git a/vendor/drush/drush/internal-copy/Config/Yaml/Unescaper.php b/vendor/drush/drush/internal-copy/Config/Yaml/Unescaper.php
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+<?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 Drush\Internal\Config\Yaml;
+
+use Drush\Internal\Config\Yaml\Exception\ParseException;
+
+/**
+ * Unescaper encapsulates unescaping rules for single and double-quoted
+ * YAML strings.
+ *
+ * @author Matthew Lewinski <matthew@lewinski.org>
+ *
+ * @internal
+ */
+class Unescaper
+{
+    /**
+     * Regex fragment that matches an escaped character in a double quoted string.
+     */
+    const REGEX_ESCAPED_CHARACTER = '\\\\(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)
+    {
+        $callback = function ($match) {
+            return $this->unescapeCharacter($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 $value An escaped character
+     *
+     * @return string The unescaped character
+     */
+    private function unescapeCharacter($value)
+    {
+        switch ($value[1]) {
+            case '0':
+                return "\x0";
+            case 'a':
+                return "\x7";
+            case 'b':
+                return "\x8";
+            case 't':
+                return "\t";
+            case "\t":
+                return "\t";
+            case 'n':
+                return "\n";
+            case 'v':
+                return "\xB";
+            case 'f':
+                return "\xC";
+            case 'r':
+                return "\r";
+            case 'e':
+                return "\x1B";
+            case ' ':
+                return ' ';
+            case '"':
+                return '"';
+            case '/':
+                return '/';
+            case '\\':
+                return '\\';
+            case 'N':
+                // U+0085 NEXT LINE
+                return "\xC2\x85";
+            case '_':
+                // U+00A0 NO-BREAK SPACE
+                return "\xC2\xA0";
+            case 'L':
+                // U+2028 LINE SEPARATOR
+                return "\xE2\x80\xA8";
+            case 'P':
+                // U+2029 PARAGRAPH SEPARATOR
+                return "\xE2\x80\xA9";
+            case 'x':
+                return self::utf8chr(hexdec(substr($value, 2, 2)));
+            case 'u':
+                return self::utf8chr(hexdec(substr($value, 2, 4)));
+            case 'U':
+                return self::utf8chr(hexdec(substr($value, 2, 8)));
+            default:
+                throw new ParseException(sprintf('Found unknown escape character "%s".', $value));
+        }
+    }
+
+    /**
+     * Get the UTF-8 character for the given code point.
+     *
+     * @param int $c The unicode code point
+     *
+     * @return string The corresponding UTF-8 character
+     */
+    private static function utf8chr($c)
+    {
+        if (0x80 > $c %= 0x200000) {
+            return chr($c);
+        }
+        if (0x800 > $c) {
+            return chr(0xC0 | $c >> 6).chr(0x80 | $c & 0x3F);
+        }
+        if (0x10000 > $c) {
+            return chr(0xE0 | $c >> 12).chr(0x80 | $c >> 6 & 0x3F).chr(0x80 | $c & 0x3F);
+        }
+
+        return chr(0xF0 | $c >> 18).chr(0x80 | $c >> 12 & 0x3F).chr(0x80 | $c >> 6 & 0x3F).chr(0x80 | $c & 0x3F);
+    }
+}