function clear($key) {
		// Normalize array literal
		$cache=Cache::instance();
		$parts=$this->cut($key);
		if ($key=='CACHE')
			// Clear cache contents
			$cache->reset();
		elseif (preg_match('/^(GET|POST|COOKIE)\b(.+)/',$key,$expr)) {
			$this->clear('REQUEST'.$expr[2]);
			if ($expr[1]=='COOKIE') {
				$parts=$this->cut($key);
				$jar=$this->hive['JAR'];
				unset($jar['lifetime']);
				$jar['expire']=0;
				call_user_func_array('setcookie',
					array_merge([$parts[1],NULL],$jar));
				unset($_COOKIE[$parts[1]]);
			}
		}
		elseif ($parts[0]=='SESSION') {
			if (!headers_sent() && session_status()!=PHP_SESSION_ACTIVE)
				session_start();
			if (empty($parts[1])) {
				// End session
				session_unset();
				session_destroy();
				$this->clear('COOKIE.'.session_name());
			}
			$this->sync('SESSION');
		}
		if (!isset($parts[1]) && array_key_exists($parts[0],$this->init))
			// Reset global to default value
			$this->hive[$parts[0]]=$this->init[$parts[0]];
		else {
			eval('unset('.$this->compile('@this->hive.'.$key).');');
			if ($parts[0]=='SESSION') {
				session_commit();
				session_start();
			}
			if ($cache->exists($hash=$this->hash($key).'.var'))
				// Remove from cache
				$cache->clear($hash);
		}
	}