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diff --git a/include/jsoncons_ext/jsonpath/jsonpath_selector.hpp b/include/jsoncons_ext/jsonpath/jsonpath_selector.hpp
new file mode 100644
index 0000000..e06d37c
--- /dev/null
+++ b/include/jsoncons_ext/jsonpath/jsonpath_selector.hpp
@@ -0,0 +1,1322 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_JSONPATH_JSONPATH_SELECTOR_HPP
+#define JSONCONS_JSONPATH_JSONPATH_SELECTOR_HPP
+
+#include <string>
+#include <vector>
+#include <memory>
+#include <type_traits> // std::is_const
+#include <limits> // std::numeric_limits
+#include <utility> // std::move
+#include <regex>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpath/jsonpath_error.hpp>
+#include <jsoncons_ext/jsonpath/expression.hpp>
+
+namespace jsoncons { 
+namespace jsonpath {
+namespace detail {
+
+    struct slice
+    {
+        jsoncons::optional<int64_t> start_;
+        jsoncons::optional<int64_t> stop_;
+        int64_t step_;
+
+        slice()
+            : start_(), stop_(), step_(1)
+        {
+        }
+
+        slice(const jsoncons::optional<int64_t>& start, const jsoncons::optional<int64_t>& end, int64_t step) 
+            : start_(start), stop_(end), step_(step)
+        {
+        }
+
+        slice(const slice& other)
+            : start_(other.start_), stop_(other.stop_), step_(other.step_)
+        {
+        }
+
+        slice& operator=(const slice& rhs) 
+        {
+            if (this != &rhs)
+            {
+                if (rhs.start_)
+                {
+                    start_ = rhs.start_;
+                }
+                else
+                {
+                    start_.reset();
+                }
+                if (rhs.stop_)
+                {
+                    stop_ = rhs.stop_;
+                }
+                else
+                {
+                    stop_.reset();
+                }
+                step_ = rhs.step_;
+            }
+            return *this;
+        }
+
+        int64_t get_start(std::size_t size) const
+        {
+            if (start_)
+            {
+                auto len = *start_ >= 0 ? *start_ : (static_cast<int64_t>(size) + *start_);
+                return len <= static_cast<int64_t>(size) ? len : static_cast<int64_t>(size);
+            }
+            else
+            {
+                if (step_ >= 0)
+                {
+                    return 0;
+                }
+                else 
+                {
+                    return static_cast<int64_t>(size);
+                }
+            }
+        }
+
+        int64_t get_stop(std::size_t size) const
+        {
+            if (stop_)
+            {
+                auto len = *stop_ >= 0 ? *stop_ : (static_cast<int64_t>(size) + *stop_);
+                return len <= static_cast<int64_t>(size) ? len : static_cast<int64_t>(size);
+            }
+            else
+            {
+                return step_ >= 0 ? static_cast<int64_t>(size) : -1;
+            }
+        }
+
+        int64_t step() const
+        {
+            return step_; // Allow negative
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class json_array_receiver : public node_receiver<Json,JsonReference>
+    {
+    public:
+        using reference = JsonReference;
+        using char_type = typename Json::char_type;
+        using json_location_node_type = json_location_node<char_type>;
+
+        Json* val;
+
+        json_array_receiver(Json* ptr)
+            : val(ptr)
+        {
+        }
+
+        void add(const json_location_node_type&, reference value) override
+        {
+            val->emplace_back(value);
+        }
+    };
+
+    template <class Json,class JsonReference>
+    struct path_generator
+    {
+        using char_type = typename Json::char_type;
+        using json_location_node_type = json_location_node<char_type>;
+        using string_type = std::basic_string<char_type>;
+
+        static const json_location_node_type& generate(dynamic_resources<Json,JsonReference>& resources,
+                                                       const json_location_node_type& last, 
+                                                       std::size_t index, 
+                                                       result_options options) 
+        {
+            const result_options require_path = result_options::path | result_options::nodups | result_options::sort;
+            if ((options & require_path) != result_options())
+            {
+                return *resources.create_path_node(&last, index);
+            }
+            else
+            {
+                return last;
+            }
+        }
+
+        static const json_location_node_type& generate(dynamic_resources<Json,JsonReference>& resources,
+                                                       const json_location_node_type& last, 
+                                                       const string_type& identifier, 
+                                                       result_options options) 
+        {
+            const result_options require_path = result_options::path | result_options::nodups | result_options::sort;
+            if ((options & require_path) != result_options())
+            {
+                return *resources.create_path_node(&last, identifier);
+            }
+            else
+            {
+                return last;
+            }
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class base_selector : public jsonpath_selector<Json,JsonReference>
+    {
+        using supertype = jsonpath_selector<Json,JsonReference>;
+
+        supertype* tail_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using json_location_type = typename supertype::json_location_type;
+        using node_receiver_type = typename supertype::node_receiver_type;
+        using selector_type = typename supertype::selector_type;
+
+        base_selector()
+            : supertype(true, 11), tail_(nullptr)
+        {
+        }
+
+        base_selector(bool is_path, std::size_t precedence_level)
+            : supertype(is_path, precedence_level), tail_(nullptr)
+        {
+        }
+
+        void append_selector(selector_type* expr) override
+        {
+            if (!tail_)
+            {
+                tail_ = expr;
+            }
+            else
+            {
+                tail_->append_selector(expr);
+            }
+        }
+
+        void tail_select(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current,
+                           node_receiver_type& receiver,
+                           result_options options) const
+        {
+            if (!tail_)
+            {
+                receiver.add(last, current);
+            }
+            else
+            {
+                tail_->select(resources, root, last, current, receiver, options);
+            }
+        }
+
+        reference evaluate_tail(dynamic_resources<Json,JsonReference>& resources,
+                                reference root,
+                                const json_location_node_type& last, 
+                                reference current, 
+                                result_options options,
+                                std::error_code& ec) const
+        {
+            if (!tail_)
+            {
+                return current;
+            }
+            else
+            {
+                return tail_->evaluate(resources, root, last, current, options, ec);
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            if (tail_)
+            {
+                s.append(tail_->to_string(level));
+            }
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class identifier_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+        using path_generator_type = path_generator<Json,JsonReference>;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using char_type = typename Json::char_type;
+        using string_type = std::basic_string<char_type>;
+        using string_view_type = basic_string_view<char_type>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+    private:
+        string_type identifier_;
+    public:
+
+        identifier_selector(const string_view_type& identifier)
+            : base_selector<Json,JsonReference>(), identifier_(identifier)
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            //std::string buf;
+            //buf.append("identifier selector: ");
+            //unicode_traits::convert(identifier_.data(),identifier_.size(),buf);
+
+            static const char_type length_name[] = {'l', 'e', 'n', 'g', 't', 'h', 0};
+
+            if (current.is_object())
+            {
+                auto it = current.find(identifier_);
+                if (it != current.object_range().end())
+                {
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, identifier_, options),
+                                        it->value(), receiver, options);
+                }
+            }
+            else if (current.is_array())
+            {
+                int64_t n{0};
+                auto r = jsoncons::detail::to_integer_decimal(identifier_.data(), identifier_.size(), n);
+                if (r)
+                {
+                    std::size_t index = (n >= 0) ? static_cast<std::size_t>(n) : static_cast<std::size_t>(static_cast<int64_t>(current.size()) + n);
+                    if (index < current.size())
+                    {
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, index, options),
+                                            current[index], receiver, options);
+                    }
+                }
+                else if (identifier_ == length_name && current.size() > 0)
+                {
+                    pointer ptr = resources.create_json(current.size());
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, identifier_, options), 
+                                        *ptr, 
+                                        receiver, options);
+                }
+            }
+            else if (current.is_string() && identifier_ == length_name)
+            {
+                string_view_type sv = current.as_string_view();
+                std::size_t count = unicode_traits::count_codepoints(sv.data(), sv.size());
+                pointer ptr = resources.create_json(count);
+                this->tail_select(resources, root, 
+                                    path_generator_type::generate(resources, last, identifier_, options), 
+                                    *ptr, receiver, options);
+            }
+            //std::cout << "end identifier_selector\n";
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            static const char_type length_name[] = {'l', 'e', 'n', 'g', 't', 'h', 0};
+
+            if (current.is_object())
+            {
+                auto it = current.find(identifier_);
+                if (it != current.object_range().end())
+                {
+                    return this->evaluate_tail(resources, root, 
+                                               path_generator_type::generate(resources, last, identifier_, options),
+                                              it->value(), options, ec);
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else if (current.is_array())
+            {
+                int64_t n{0};
+                auto r = jsoncons::detail::to_integer_decimal(identifier_.data(), identifier_.size(), n);
+                if (r)
+                {
+                    std::size_t index = (n >= 0) ? static_cast<std::size_t>(n) : static_cast<std::size_t>(static_cast<int64_t>(current.size()) + n);
+                    if (index < current.size())
+                    {
+                        return this->evaluate_tail(resources, root, 
+                                                   path_generator_type::generate(resources, last, index, options),
+                                                   current[index], options, ec);
+                    }
+                    else
+                    {
+                        return resources.null_value();
+                    }
+                }
+                else if (identifier_ == length_name && current.size() > 0)
+                {
+                    pointer ptr = resources.create_json(current.size());
+                    return this->evaluate_tail(resources, root, 
+                                               path_generator_type::generate(resources, last, identifier_, options), 
+                                               *ptr, 
+                                               options, ec);
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else if (current.is_string() && identifier_ == length_name)
+            {
+                string_view_type sv = current.as_string_view();
+                std::size_t count = unicode_traits::count_codepoints(sv.data(), sv.size());
+                pointer ptr = resources.create_json(count);
+                return this->evaluate_tail(resources, root, 
+                                           path_generator_type::generate(resources, last, identifier_, options), 
+                                           *ptr, options, ec);
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("identifier selector ");
+            unicode_traits::convert(identifier_.data(),identifier_.size(),s);
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+            //s.append("\n");
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class root_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+        using path_generator_type = path_generator<Json,JsonReference>;
+
+        std::size_t id_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        root_selector(std::size_t id)
+            : base_selector<Json,JsonReference>(), id_(id)
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+                this->tail_select(resources, root, last, root, receiver, options);
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            if (resources.is_cached(id_))
+            {
+                return resources.retrieve_from_cache(id_);
+            }
+            else
+            {
+                auto& ref = this->evaluate_tail(resources, root, last, root, options, ec);
+                if (!ec)
+                {
+                    resources.add_to_cache(id_, ref);
+                }
+
+                return ref;
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("root_selector ");
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class current_node_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        current_node_selector()
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            this->tail_select(resources,  
+                                root, last, current, receiver, options);
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            //std::cout << "current_node_selector: " << current << "\n";
+            return this->evaluate_tail(resources,  
+                                root, last, current, options, ec);
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("current_node_selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class parent_node_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        int ancestor_depth_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using json_location_type = typename supertype::json_location_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        parent_node_selector(int ancestor_depth)
+        {
+            ancestor_depth_ = ancestor_depth;
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            const json_location_node_type* ancestor = std::addressof(last);
+            int index = 0;
+            while (ancestor != nullptr && index < ancestor_depth_)
+            {
+                ancestor = ancestor->parent();
+                ++index;
+            }
+
+            if (ancestor != nullptr)
+            {
+                json_location_type path(*ancestor);
+                pointer ptr = jsoncons::jsonpath::select(root,path);
+                if (ptr != nullptr)
+                {
+                    this->tail_select(resources, root, path.last(), *ptr, receiver, options);        
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            const json_location_node_type* ancestor = std::addressof(last);
+            int index = 0;
+            while (ancestor != nullptr && index < ancestor_depth_)
+            {
+                ancestor = ancestor->parent();
+                ++index;
+            }
+
+            if (ancestor != nullptr)
+            {
+                json_location_type path(*ancestor);
+                pointer ptr = jsoncons::jsonpath::select(root,path);
+                if (ptr != nullptr)
+                {
+                    return this->evaluate_tail(resources, root, path.last(), *ptr, options, ec);        
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("parent_node_selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class index_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        int64_t index_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        index_selector(int64_t index)
+            : base_selector<Json,JsonReference>(), index_(index)
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                int64_t slen = static_cast<int64_t>(current.size());
+                if (index_ >= 0 && index_ < slen)
+                {
+                    std::size_t i = static_cast<std::size_t>(index_);
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, i, options), 
+                                        current.at(i), receiver, options);
+                }
+                else 
+                {
+                    int64_t index = slen + index_;
+                    if (index >= 0 && index < slen)
+                    {
+                        std::size_t i = static_cast<std::size_t>(index);
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, i, options), 
+                                            current.at(i), receiver, options);
+                    }
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            if (current.is_array())
+            {
+                int64_t slen = static_cast<int64_t>(current.size());
+                if (index_ >= 0 && index_ < slen)
+                {
+                    std::size_t i = static_cast<std::size_t>(index_);
+                    return this->evaluate_tail(resources, root, 
+                                        path_generator_type::generate(resources, last, i, options), 
+                                        current.at(i), options, ec);
+                }
+                else 
+                {
+                    int64_t index = slen + index_;
+                    if (index >= 0 && index < slen)
+                    {
+                        std::size_t i = static_cast<std::size_t>(index);
+                        return this->evaluate_tail(resources, root, 
+                                            path_generator_type::generate(resources, last, i, options), 
+                                            current.at(i), options, ec);
+                    }
+                    else
+                    {
+                        return resources.null_value();
+                    }
+                }
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class wildcard_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        wildcard_selector()
+            : base_selector<Json,JsonReference>()
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                for (std::size_t i = 0; i < current.size(); ++i)
+                {
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, i, options), current[i], 
+                                        receiver, options);
+                }
+            }
+            else if (current.is_object())
+            {
+                for (auto& member : current.object_range())
+                {
+                    this->tail_select(resources, root, 
+                                        path_generator_type::generate(resources, last, member.key(), options), 
+                                        member.value(), receiver, options);
+                }
+            }
+            //std::cout << "end wildcard_selector\n";
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources, root, last, current, receiver, options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("wildcard selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class recursive_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        recursive_selector()
+            : base_selector<Json,JsonReference>()
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                this->tail_select(resources, root, last, current, receiver, options);
+                for (std::size_t i = 0; i < current.size(); ++i)
+                {
+                    select(resources, root, 
+                           path_generator_type::generate(resources, last, i, options), current[i], receiver, options);
+                }
+            }
+            else if (current.is_object())
+            {
+                this->tail_select(resources, root, last, current, receiver, options);
+                for (auto& item : current.object_range())
+                {
+                    select(resources, root, 
+                           path_generator_type::generate(resources, last, item.key(), options), item.value(), receiver, options);
+                }
+            }
+            //std::cout << "end wildcard_selector\n";
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources, root, last, current, receiver, options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("wildcard selector");
+            s.append(base_selector<Json,JsonReference>::to_string(level));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class union_selector final : public jsonpath_selector<Json,JsonReference>
+    {
+        using supertype = jsonpath_selector<Json,JsonReference>;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using json_location_type = typename supertype::json_location_type;
+        using path_expression_type = path_expression<Json, JsonReference>;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+        using selector_type = typename supertype::selector_type;
+    private:
+        std::vector<selector_type*> selectors_;
+        selector_type* tail_;
+    public:
+        union_selector(std::vector<selector_type*>&& selectors)
+            : supertype(true, 11), selectors_(std::move(selectors)), tail_(nullptr)
+        {
+        }
+
+        void append_selector(selector_type* tail) override
+        {
+            if (tail_ == nullptr)
+            {
+                tail_ = tail;
+                for (auto& selector : selectors_)
+                {
+                    selector->append_selector(tail);
+                }
+            }
+            else
+            {
+                tail_->append_selector(tail);
+            }
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            for (auto& selector : selectors_)
+            {
+                selector->select(resources, root, last, current, receiver, options);
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources,root,last,current,receiver,options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("union selector ");
+            for (auto& selector : selectors_)
+            {
+                s.append(selector->to_string(level+1));
+                //s.push_back('\n');
+            }
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class filter_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        expression<Json,JsonReference> expr_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        filter_selector(expression<Json,JsonReference>&& expr)
+            : base_selector<Json,JsonReference>(), expr_(std::move(expr))
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                for (std::size_t i = 0; i < current.size(); ++i)
+                {
+                    std::error_code ec;
+                    value_type r = expr_.evaluate(resources, root, current[i], options, ec);
+                    bool t = ec ? false : detail::is_true(r);
+                    if (t)
+                    {
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, i, options), 
+                                            current[i], receiver, options);
+                    }
+                }
+            }
+            else if (current.is_object())
+            {
+                for (auto& member : current.object_range())
+                {
+                    std::error_code ec;
+                    value_type r = expr_.evaluate(resources, root, member.value(), options, ec);
+                    bool t = ec ? false : detail::is_true(r);
+                    if (t)
+                    {
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, member.key(), options), 
+                                            member.value(), receiver, options);
+                    }
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> receiver(jptr);
+            select(resources, root, last, current, receiver, options);
+            return *jptr;
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("filter selector ");
+            s.append(expr_.to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class index_expression_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        expression<Json,JsonReference> expr_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        index_expression_selector(expression<Json,JsonReference>&& expr)
+            : base_selector<Json,JsonReference>(), expr_(std::move(expr))
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            std::error_code ec;
+            value_type j = expr_.evaluate(resources, root, current, options, ec);
+
+            if (!ec)
+            {
+                if (j.template is<std::size_t>() && current.is_array())
+                {
+                    std::size_t start = j.template as<std::size_t>();
+                    this->tail_select(resources, root, 
+                                      path_generator_type::generate(resources, last, start, options),
+                                      current.at(start), receiver, options);
+                }
+                else if (j.is_string() && current.is_object())
+                {
+                    this->tail_select(resources, root, 
+                                      path_generator_type::generate(resources, last, j.as_string(), options),
+                                      current.at(j.as_string_view()), receiver, options);
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            //std::cout << "index_expression_selector current: " << current << "\n";
+
+            value_type j = expr_.evaluate(resources, root, current, options, ec);
+
+            if (!ec)
+            {
+                if (j.template is<std::size_t>() && current.is_array())
+                {
+                    std::size_t start = j.template as<std::size_t>();
+                    return this->evaluate_tail(resources, root, last, current.at(start), options, ec);
+                }
+                else if (j.is_string() && current.is_object())
+                {
+                    return this->evaluate_tail(resources, root, last, current.at(j.as_string_view()), options, ec);
+                }
+                else
+                {
+                    return resources.null_value();
+                }
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("bracket expression selector ");
+            s.append(expr_.to_string(level+1));
+            s.append(base_selector<Json,JsonReference>::to_string(level+1));
+
+            return s;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class slice_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+        using path_generator_type = path_generator<Json, JsonReference>;
+
+        slice slice_;
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        slice_selector(const slice& slic)
+            : base_selector<Json,JsonReference>(), slice_(slic) 
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current,
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            if (current.is_array())
+            {
+                auto start = slice_.get_start(current.size());
+                auto end = slice_.get_stop(current.size());
+                auto step = slice_.step();
+
+                if (step > 0)
+                {
+                    if (start < 0)
+                    {
+                        start = 0;
+                    }
+                    if (end > static_cast<int64_t>(current.size()))
+                    {
+                        end = current.size();
+                    }
+                    for (int64_t i = start; i < end; i += step)
+                    {
+                        std::size_t j = static_cast<std::size_t>(i);
+                        this->tail_select(resources, root, 
+                                            path_generator_type::generate(resources, last, j, options), 
+                                            current[j], receiver, options);
+                    }
+                }
+                else if (step < 0)
+                {
+                    if (start >= static_cast<int64_t>(current.size()))
+                    {
+                        start = static_cast<int64_t>(current.size()) - 1;
+                    }
+                    if (end < -1)
+                    {
+                        end = -1;
+                    }
+                    for (int64_t i = start; i > end; i += step)
+                    {
+                        std::size_t j = static_cast<std::size_t>(i);
+                        if (j < current.size())
+                        {
+                            this->tail_select(resources, root, 
+                                                path_generator_type::generate(resources, last,j,options), current[j], receiver, options);
+                        }
+                    }
+                }
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code&) const override
+        {
+            auto jptr = resources.create_json(json_array_arg);
+            json_array_receiver<Json,JsonReference> accum(jptr);
+            select(resources, root, last, current, accum, options);
+            return *jptr;
+        }
+    };
+
+    template <class Json,class JsonReference>
+    class function_selector final : public base_selector<Json,JsonReference>
+    {
+        using supertype = base_selector<Json,JsonReference>;
+
+        expression<Json,JsonReference> expr_;
+
+    public:
+        using value_type = typename supertype::value_type;
+        using reference = typename supertype::reference;
+        using pointer = typename supertype::pointer;
+        using path_value_pair_type = typename supertype::path_value_pair_type;
+        using json_location_node_type = typename supertype::json_location_node_type;
+        using path_generator_type = path_generator<Json,JsonReference>;
+        using node_receiver_type = typename supertype::node_receiver_type;
+
+        function_selector(expression<Json,JsonReference>&& expr)
+            : base_selector<Json,JsonReference>(), expr_(std::move(expr))
+        {
+        }
+
+        void select(dynamic_resources<Json,JsonReference>& resources,
+                    reference root,
+                    const json_location_node_type& last, 
+                    reference current, 
+                    node_receiver_type& receiver,
+                    result_options options) const override
+        {
+            std::error_code ec;
+            value_type ref = expr_.evaluate(resources, root, current, options, ec);
+            if (!ec)
+            {
+                this->tail_select(resources, root, last, *resources.create_json(std::move(ref)), receiver, options);
+            }
+        }
+
+        reference evaluate(dynamic_resources<Json,JsonReference>& resources,
+                           reference root,
+                           const json_location_node_type& last, 
+                           reference current, 
+                           result_options options,
+                           std::error_code& ec) const override
+        {
+            value_type ref = expr_.evaluate(resources, root, current, options, ec);
+            if (!ec)
+            {
+                return this->evaluate_tail(resources, root, last, *resources.create_json(std::move(ref)), 
+                                    options, ec);
+            }
+            else
+            {
+                return resources.null_value();
+            }
+        }
+
+        std::string to_string(int level = 0) const override
+        {
+            std::string s;
+            if (level > 0)
+            {
+                s.append("\n");
+                s.append(level*2, ' ');
+            }
+            s.append("function_selector ");
+            s.append(expr_.to_string(level+1));
+
+            return s;
+        }
+    };
+
+} // namespace detail
+} // namespace jsonpath
+} // namespace jsoncons
+
+#endif