diff -r 000000000000 -r 9005fdd81bca src/RecfileHandler.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/RecfileHandler.h	Sat Mar 30 01:12:42 2019 +0100
@@ -0,0 +1,138 @@
+/**
+ * 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 <string>
+#include <vector>
+#include <iostream>
+#include <sstream>
+#include <locale>
+#include <codecvt>
+#include <regex>
+#include <cassert>
+
+#include <relpipe/reader/typedefs.h>
+#include <relpipe/reader/TypeId.h>
+#include <relpipe/reader/handlers/RelationalReaderValueHandler.h>
+#include <relpipe/reader/handlers/AttributeMetadata.h>
+
+#include "RecfileWriter.h"
+
+namespace relpipe {
+namespace out {
+namespace recfile {
+
+using namespace relpipe::reader;
+
+class RecfileHandler : public handlers::RelationalReaderValueHadler {
+private:
+	shared_ptr<RecfileWriter> recfileWriter;
+	std::vector<TypeId> columnTypes;
+	std::vector<string_t> columnTypeCodes;
+	std::vector<string_t> columnNames;
+	integer_t valueCount = 0;
+	integer_t columnCount = 0;
+	integer_t relationCount = 0;
+
+public:
+
+	RecfileHandler(std::ostream& output) : recfileWriter(new RecfileWriter(output)) {
+	}
+
+	void startRelation(string_t name, std::vector<handlers::AttributeMetadata> attributes) override {
+		valueCount = 0;
+		columnCount = 0;
+
+		if (relationCount == 0) {
+			recfileWriter->writeStartSequence(); // root
+		} else {
+			recfileWriter->writeEndSequence();
+			recfileWriter->writeEndSequence();
+		}
+		relationCount++;
+		recfileWriter->writeStartSequence(); // relation
+
+		recfileWriter->writeString(name);
+
+
+		recfileWriter->writeStartSequence(); // relation metadata
+		columnCount = attributes.size();
+		columnTypes.resize(columnCount);
+		columnTypeCodes.resize(columnCount);
+		columnNames.resize(columnCount);
+		for (int i = 0; i < attributes.size(); i++) {
+			columnNames[i] = attributes[i].getAttributeName();
+			columnTypes[i] = attributes[i].getTypeId();
+			columnTypeCodes[i] = attributes[i].getTypeName();
+			
+			recfileWriter->writeStartSequence(); // attribute-metadata
+			recfileWriter->writeString(columnNames[i]);
+			recfileWriter->writeString(columnTypeCodes[i]);
+			recfileWriter->writeEndSequence();
+		}
+		recfileWriter->writeEndSequence();
+
+	}
+
+	void attribute(const void* value, const std::type_info& type) override {
+		integer_t i = valueCount % columnCount;
+
+		if (i == 0 && valueCount) recfileWriter->writeEndSequence();
+		if (i == 0) recfileWriter->writeStartSequence();
+
+		valueCount++;
+		
+		switch (columnTypes[i]) {
+			case TypeId::BOOLEAN:
+			{
+				assert(type == typeid (boolean_t));
+				auto* typedValue = static_cast<const boolean_t*> (value);
+				recfileWriter->writeBoolean(*typedValue);
+				break;
+			}
+			case TypeId::INTEGER:
+			{
+				assert(type == typeid (integer_t));
+				auto* typedValue = static_cast<const integer_t*> (value);
+				recfileWriter->writeInteger(*typedValue);
+				break;
+			}
+			case TypeId::STRING:
+			{
+				assert(type == typeid (string_t));
+				auto* typedValue = static_cast<const string_t*> (value);
+				recfileWriter->writeString(*typedValue);
+				break;
+			}
+			default:
+				throw cli::RelpipeCLIException(L"Unsupported type in RecfileHandler.attribute()", cli::CLI::EXIT_CODE_UNEXPECTED_ERROR);
+		}
+		
+	}
+
+	void endOfPipe() {
+		if (valueCount) recfileWriter->writeEndSequence();
+		if (relationCount) recfileWriter->writeEndSequence();
+		recfileWriter->writeEndSequence();
+	}
+
+};
+
+}
+}
+}