New ScanIterator class.

Not yet tested and only supporting the SCAN command for now, more to
come.
Also includes some refactoring that was needed to make everything work.

src/backends/redis/scan_iterator.cpp

@@ -0,0 +1,46 @@
+/* Copyright 2015, 2016, Michele Santullo
+ * This file is part of "dindexer".
+ *
+ * "dindexer" 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.
+ *
+ * "dindexer" 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 "dindexer".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "scan_iterator.hpp"
+#include "command.hpp"
+#include <cassert>
+#include <ciso646>
+#include <boost/lexical_cast.hpp>
+#include <string>
+
+namespace redis {
+	namespace implem {
+		ScanIteratorBaseClass::ScanIteratorBaseClass (Command* parCommand) :
+			m_command(parCommand)
+		{
+			assert(m_command);
+			assert(m_command->is_connected());
+		}
+
+		bool ScanIteratorBaseClass::is_connected() const {
+			return m_command and m_command->is_connected();
+		}
+
+		RedisReplyType ScanIteratorBaseClass::run (const char* parCommand, long long parScanContext) {
+			return m_command->run(parCommand, boost::lexical_cast<std::string>(parScanContext));
+		}
+
+		RedisReplyType ScanIteratorBaseClass::run (const char* parCommand, const std::string& parParameter, long long parScanContext) {
+			return m_command->run(parCommand, parParameter, boost::lexical_cast<std::string>(parScanContext));
+		}
+	} //namespace implem
+} //namespace redis