src: Avoid use of `detail` folder for installable headers

This commit moves `lp/detail/*` to `lp/`, as `detail` folders should
include only private APIs that are only used during the build and cannot
be used (header files not installed) by external applications.

Change-Id: I370592819c4bc5f4016689ef7c9c5bd2cdd0eaa2
diff --git a/src/lp/field-info.hpp b/src/lp/field-info.hpp
new file mode 100644
index 0000000..5cb618c
--- /dev/null
+++ b/src/lp/field-info.hpp
@@ -0,0 +1,95 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2013-2017 Regents of the University of California.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library 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 Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#ifndef NDN_CXX_LP_FIELD_INFO_HPP
+#define NDN_CXX_LP_FIELD_INFO_HPP
+
+#include "../common.hpp"
+
+#include "fields.hpp"
+
+namespace ndn {
+namespace lp {
+
+class FieldInfo
+{
+public:
+  FieldInfo();
+
+  explicit
+  FieldInfo(uint64_t tlv);
+
+public:
+  /**
+   * \brief TLV-TYPE of the field; 0 if field does not exist
+   */
+  uint64_t tlvType;
+
+  /**
+   * \brief is this field known
+   */
+  bool isRecognized;
+
+  /**
+   * \brief can this unknown field be ignored
+   */
+  bool canIgnore;
+
+  /**
+   * \brief is the field repeatable
+   */
+  bool isRepeatable;
+
+  /**
+   * \brief sort order of field_location_tag
+   */
+  int locationSortOrder;
+};
+
+template<typename TAG>
+inline int
+getLocationSortOrder();
+
+template<>
+inline int
+getLocationSortOrder<field_location_tags::Header>()
+{
+  return 1;
+}
+
+template<>
+inline int
+getLocationSortOrder<field_location_tags::Fragment>()
+{
+  return 2;
+}
+
+inline bool
+compareFieldSortOrder(const FieldInfo& first, const FieldInfo& second)
+{
+  return (first.locationSortOrder < second.locationSortOrder) ||
+         (first.locationSortOrder == second.locationSortOrder && first.tlvType < second.tlvType);
+}
+
+} // namespace lp
+} // namespace ndn
+
+#endif // NDN_CXX_LP_FIELD_INFO_HPP