Seperate query classes from xml classes to allow specifying more information in the query

src/Query/Operator.php

@@ -0,0 +1,67 @@
+<?php
+/**
+ * @copyright Copyright (c) 2018 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace SearchDAV\Query;
+
+class Operator {
+	const OPERATION_AND = '{DAV:}and';
+	const OPERATION_OR = '{DAV:}or';
+	const OPERATION_NOT = '{DAV:}not';
+	const OPERATION_EQUAL = '{DAV:}eq';
+	const OPERATION_LESS_THAN = '{DAV:}lt';
+	const OPERATION_LESS_OR_EQUAL_THAN = '{DAV:}lte';
+	const OPERATION_GREATER_THAN = '{DAV:}gt';
+	const OPERATION_GREATER_OR_EQUAL_THAN = '{DAV:}gte';
+	const OPERATION_IS_COLLECTION = '{DAV:}is-collection';
+	const OPERATION_IS_DEFINED = '{DAV:}is-defined';
+	const OPERATION_IS_LIKE = '{DAV:}like';
+	const OPERATION_CONTAINS = '{DAV:}contains';
+
+	/**
+	 * @var string
+	 *
+	 * The type of operation, one of the Operator::OPERATION_* constants
+	 */
+	public $type;
+	/**
+	 * @var (Literal|SearchPropDefinition|Operation)[]
+	 *
+	 * The list of arguments for the operation
+	 *
+	 *  - SearchPropDefinition: property for comparison
+	 *  - Literal: literal value for comparison
+	 *  - Operation: nested operation for and/or/not operations
+	 *
+	 * Which type and what number of argument an Operator takes depends on the operator type.
+	 */
+	public $arguments;
+
+	/**
+	 * Operator constructor.
+	 *
+	 * @param string $type
+	 * @param array $arguments
+	 */
+	public function __construct($type = '', array $arguments = []) {
+		$this->type = $type;
+		$this->arguments = $arguments;
+	}
+}