diff -r 62eac7ab4cf4 -r d44ed75822e7 src/RequestedField.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/RequestedField.h	Wed Jan 16 17:23:05 2019 +0100
@@ -0,0 +1,51 @@
+/**
+ * Relational pipes
+ * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <vector>
+
+#include <relpipe/writer/typedefs.h>
+
+namespace relpipe {
+namespace in {
+namespace filesystem {
+
+using namespace relpipe::writer;
+
+class RequestedField {
+public:
+	static const string_t GROUP_FILE;
+	static const string_t GROUP_XATTR;
+	string_t group;
+	string_t name;
+	std::vector<string_t> aliases;
+	std::map<string_t, string_t> options;
+
+	RequestedField(const string_t& group, const string_t& name, const std::vector<string_t>& aliases = {}, const std::map<string_t, string_t>& options = {}) : group(group), name(name), aliases(aliases), options(options) {
+	}
+
+	virtual ~RequestedField() {
+	}
+};
+
+const string_t RequestedField::GROUP_FILE = L"file";
+const string_t RequestedField::GROUP_XATTR = L"xattr";
+
+}
+}
+}