1 files changed, 137 insertions, 0 deletions
diff --git a/include/orcus/json_structure_tree.hpp b/include/orcus/json_structure_tree.hpp
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+++ b/include/orcus/json_structure_tree.hpp
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#ifndef INCLUDED_ORCUS_JSON_STRUCTURE_TREE_HPP
+#define INCLUDED_ORCUS_JSON_STRUCTURE_TREE_HPP
+
+#include "orcus/env.hpp"
+#include "orcus/types.hpp"
+
+#include <ostream>
+#include <memory>
+#include <vector>
+#include <functional>
+
+namespace orcus { namespace json {
+
+struct ORCUS_DLLPUBLIC table_range_t
+{
+    std::vector<std::string> paths;
+    std::vector<std::string> row_groups;
+};
+
+class ORCUS_DLLPUBLIC structure_tree
+{
+    struct impl;
+    std::unique_ptr<impl> mp_impl;
+
+public:
+
+    enum class node_type : short { unknown = 0, array = 1, object = 2, object_key = 3, value = 4 };
+
+    struct node_properties
+    {
+        node_type type;
+        bool repeat;
+    };
+
+    class ORCUS_DLLPUBLIC walker
+    {
+        friend class structure_tree;
+
+        struct impl;
+        std::unique_ptr<impl> mp_impl;
+
+        walker(const structure_tree::impl* parent_impl);
+    public:
+        walker();
+        walker(const walker& other);
+        ~walker();
+
+        /**
+         * Set the current position to the root node, and return its
+         * properties.
+         */
+        void root();
+
+        /**
+         * Move down to a child node at specified position.  Call
+         * child_count() to get the number of child nodes the current node
+         * has. A child node position is 0-based and must be less than the
+         * child count.
+         *
+         * @param child_pos 0-based index of the child node to move down to.
+         */
+        void descend(size_t child_pos);
+
+        /**
+         * Move up to the parent node of the current node.
+         */
+        void ascend();
+
+        /**
+         * Return the number of child nodes the current node has.
+         *
+         * @return number of child nodes of the current node.
+         */
+        size_t child_count() const;
+
+        /**
+         * Get the properties of the current node.
+         */
+        node_properties get_node() const;
+
+        /**
+         * Build one or more field paths for the current value node.  For a
+         * value node that is a child of an object, you'll always get one
+         * path, whereas a value node that is a chlid of an array, you may get
+         * more than one field paths.
+         *
+         * @return one or more field paths built for the current value node.
+         */
+        std::vector<std::string> build_field_paths() const;
+
+        /**
+         * Build a path for the parent of the current repeating node.  A row
+         * group is an anchor to which repeating nodes get anchored to.  It is
+         * used to determine when to increment row position during mapping.
+         *
+         * @return path for the row group of the current repeating node.
+         */
+        std::string build_row_group_path() const;
+    };
+
+    structure_tree(const structure_tree&) = delete;
+    structure_tree& operator= (const structure_tree&) = delete;
+
+    structure_tree();
+    ~structure_tree();
+
+    void parse(std::string_view stream);
+
+    /**
+     * For now, normalizing a tree just means sorting child nodes.  We may add
+     * other normalization stuff later.
+     */
+    void normalize_tree();
+
+    void dump_compact(std::ostream& os) const;
+
+    walker get_walker() const;
+
+    using range_handler_type = std::function<void(table_range_t&&)>;
+
+    void process_ranges(range_handler_type rh) const;
+};
+
+ORCUS_DLLPUBLIC std::ostream& operator<< (std::ostream& os, structure_tree::node_type nt);
+
+}}
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */