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1 files changed, 1745 insertions, 0 deletions

diff --git a/include/jsoncons_ext/jsonschema/keyword_validator.hpp b/include/jsoncons_ext/jsonschema/keyword_validator.hpp
new file mode 100644
index 0000000..249c7d0
--- /dev/null
+++ b/include/jsoncons_ext/jsonschema/keyword_validator.hpp
@@ -0,0 +1,1745 @@
+// Copyright 2020 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_JSONSCHEMA_KEYWORD_VALIDATOR_HPP
+#define JSONCONS_JSONSCHEMA_KEYWORD_VALIDATOR_HPP
+
+#include <jsoncons/config/jsoncons_config.hpp>
+#include <jsoncons/uri.hpp>
+#include <jsoncons/json.hpp>
+#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
+#include <jsoncons_ext/jsonschema/subschema.hpp>
+#include <jsoncons_ext/jsonschema/format_validator.hpp>
+#include <cassert>
+#include <set>
+#include <sstream>
+#include <iostream>
+#include <cassert>
+#if defined(JSONCONS_HAS_STD_REGEX)
+#include <regex>
+#endif
+
+namespace jsoncons {
+namespace jsonschema {
+
+    template <class Json>
+    class abstract_keyword_validator_factory
+    {
+    public:
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        virtual ~abstract_keyword_validator_factory() = default;
+
+        virtual validator_pointer make_keyword_validator(const Json& schema,
+                                                         const std::vector<schema_location>& uris,
+                                                         const std::vector<std::string>& keys) = 0;
+        virtual validator_pointer make_required_validator(const std::vector<schema_location>& uris,
+                                                          const std::vector<std::string>& items) = 0;
+
+        virtual validator_pointer make_null_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_true_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_false_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_object_validator(const Json& sch, 
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_array_validator(const Json& sch,
+                                                       const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_string_validator(const Json& sch,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_boolean_validator(const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_integer_validator(const Json& sch, 
+                                                         const std::vector<schema_location>& uris, 
+                                                         std::set<std::string>& keywords) = 0;
+
+        virtual validator_pointer make_number_validator(const Json& sch, 
+                                                        const std::vector<schema_location>& uris, 
+                                                        std::set<std::string>& keywords) = 0;
+
+        virtual validator_pointer make_not_validator(const Json& schema,
+                                                     const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_all_of_validator(const Json& schema,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_any_of_validator(const Json& schema,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_one_of_validator(const Json& schema,
+                                                        const std::vector<schema_location>& uris) = 0;
+
+        virtual validator_pointer make_type_validator(const Json& schema,
+                                                      const std::vector<schema_location>& uris) = 0;
+    };
+
+    struct collecting_error_reporter : public error_reporter
+    {
+        std::vector<validation_output> errors;
+
+    private:
+        void do_error(const validation_output& o) override
+        {
+            errors.push_back(o);
+        }
+    };
+
+    // string keyword_validator
+
+    inline
+    std::string make_absolute_keyword_location(const std::vector<schema_location>& uris,
+                                               const std::string& keyword)
+    {
+        for (auto it = uris.rbegin(); it != uris.rend(); ++it)
+        {
+            if (!it->has_identifier() && it->is_absolute())
+            {
+                return it->append(keyword).string();
+            }
+        }
+        return "";
+    }
+
+    template <class Json>
+    class string_validator : public keyword_validator<Json>
+    {
+        jsoncons::optional<std::size_t> max_length_;
+        std::string max_length_location_;
+        jsoncons::optional<std::size_t> min_length_;
+        std::string min_length_location_;
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+        jsoncons::optional<std::regex> pattern_;
+        std::string pattern_string_;
+        std::string pattern_location_;
+    #endif
+
+        format_checker format_check_;
+        std::string format_location_;
+
+        jsoncons::optional<std::string> content_encoding_;
+        std::string content_encoding_location_;
+        jsoncons::optional<std::string> content_media_type_;
+        std::string content_media_type_location_;
+
+    public:
+        string_validator(const Json& sch, const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), max_length_(), min_length_(), 
+    #if defined(JSONCONS_HAS_STD_REGEX)
+              pattern_(),
+    #endif
+              content_encoding_(), content_media_type_()
+        {
+            auto it = sch.find("maxLength");
+            if (it != sch.object_range().end()) 
+            {
+                max_length_ = it->value().template as<std::size_t>();
+                max_length_location_ = make_absolute_keyword_location(uris, "maxLength");
+            }
+
+            it = sch.find("minLength");
+            if (it != sch.object_range().end()) 
+            {
+                min_length_ = it->value().template as<std::size_t>();
+                min_length_location_ = make_absolute_keyword_location(uris, "minLength");
+            }
+
+            it = sch.find("contentEncoding");
+            if (it != sch.object_range().end()) 
+            {
+                content_encoding_ = it->value().template as<std::string>();
+                content_encoding_location_ = make_absolute_keyword_location(uris, "contentEncoding");
+                // If "contentEncoding" is set to "binary", a Json value
+                // of type json_type::byte_string_value is accepted.
+            }
+
+            it = sch.find("contentMediaType");
+            if (it != sch.object_range().end()) 
+            {
+                content_media_type_ = it->value().template as<std::string>();
+                content_media_type_location_ = make_absolute_keyword_location(uris, "contentMediaType");
+            }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+            it = sch.find("pattern");
+            if (it != sch.object_range().end()) 
+            {
+                pattern_string_ = it->value().template as<std::string>();
+                pattern_ = std::regex(it->value().template as<std::string>(),std::regex::ECMAScript);
+                pattern_location_ = make_absolute_keyword_location(uris, "pattern");
+            }
+    #endif
+
+            it = sch.find("format");
+            if (it != sch.object_range().end()) 
+            {
+                format_location_ = make_absolute_keyword_location(uris, "format");
+                std::string format = it->value().template as<std::string>();
+                if (format == "date-time")
+                {
+                    format_check_ = rfc3339_date_time_check;
+                }
+                else if (format == "date") 
+                {
+                    format_check_ = rfc3339_date_check;
+                } 
+                else if (format == "time") 
+                {
+                    format_check_ = rfc3339_time_check;
+                } 
+                else if (format == "email") 
+                {
+                    format_check_ = email_check;
+                } 
+                else if (format == "hostname") 
+                {
+                    format_check_ = hostname_check;
+                } 
+                else if (format == "ipv4") 
+                {
+                    format_check_ = ipv4_check;
+                } 
+                else if (format == "ipv6") 
+                {
+                    format_check_ = ipv6_check;
+                } 
+                else if (format == "regex") 
+                {
+                    format_check_ = regex_check;
+                } 
+                else
+                {
+                    // Not supported - ignore
+                }
+            }
+        }
+
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter,
+                         Json&) const override
+        {
+            std::string content;
+            if (content_encoding_)
+            {
+                if (*content_encoding_ == "base64")
+                {
+                    auto s = instance.template as<jsoncons::string_view>();
+                    auto retval = jsoncons::decode_base64(s.begin(), s.end(), content);
+                    if (retval.ec != jsoncons::conv_errc::success)
+                    {
+                        reporter.error(validation_output("contentEncoding", 
+                                                         content_encoding_location_, 
+                                                         instance_location.to_uri_fragment(), 
+                                                         "Content is not a base64 string"));
+                        if (reporter.fail_early())
+                        {
+                            return;
+                        }
+                    }
+                }
+                else if (!content_encoding_->empty())
+                {
+                    reporter.error(validation_output("contentEncoding", 
+                                                     content_encoding_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "unable to check for contentEncoding '" + *content_encoding_ + "'"));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+            else
+            {
+                content = instance.template as<std::string>();
+            }
+
+            if (content_media_type_) 
+            {
+                if (content_media_type_ == "application/Json")
+                {
+                    json_string_reader reader(content);
+                    std::error_code ec;
+                    reader.read(ec);
+
+                    if (ec)
+                    {
+                        reporter.error(validation_output("contentMediaType", 
+                                                         content_media_type_location_, 
+                                                         instance_location.to_uri_fragment(), 
+                                                         std::string("Content is not JSON: ") + ec.message()));
+                    }
+                }
+            } 
+            else if (instance.type() == json_type::byte_string_value) 
+            {
+                reporter.error(validation_output("contentMediaType", 
+                                                 content_media_type_location_, 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Expected string, but is byte string"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (instance.type() != json_type::string_value) 
+            {
+                return; 
+            }
+
+            if (min_length_) 
+            {
+                std::size_t length = unicode_traits::count_codepoints(content.data(), content.size());
+                if (length < *min_length_) 
+                {
+                    reporter.error(validation_output("minLength", 
+                                                     min_length_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::string("Expected minLength: ") + std::to_string(*min_length_)
+                                              + ", actual: " + std::to_string(length)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (max_length_) 
+            {
+                std::size_t length = unicode_traits::count_codepoints(content.data(), content.size());
+                if (length > *max_length_)
+                {
+                    reporter.error(validation_output("maxLength", 
+                                                     max_length_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::string("Expected maxLength: ") + std::to_string(*max_length_)
+                        + ", actual: " + std::to_string(length)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+            if (pattern_)
+            {
+                if (!std::regex_search(content, *pattern_))
+                {
+                    std::string message("String \"");
+                    message.append(instance.template as<std::string>());
+                    message.append("\" does not match pattern \"");
+                    message.append(pattern_string_);
+                    message.append("\"");
+                    reporter.error(validation_output("pattern", 
+                                                     pattern_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::move(message)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+    #endif
+
+            if (format_check_ != nullptr) 
+            {
+                format_check_(format_location_, instance_location, content, reporter);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+        }
+    };
+
+    // not_validator
+
+    template <class Json>
+    class not_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        validator_pointer rule_;
+
+    public:
+        not_validator(abstract_keyword_validator_factory<Json>* builder,
+                 const Json& sch,
+                 const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+            rule_ = builder->make_keyword_validator(sch, uris, {"not"});
+        }
+
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const final
+        {
+            collecting_error_reporter local_reporter;
+            rule_->validate(instance, instance_location, local_reporter, patch);
+
+            if (local_reporter.errors.empty())
+            {
+                reporter.error(validation_output("not", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance must not be valid against schema"));
+            }
+        }
+
+        jsoncons::optional<Json> get_default_value(const jsonpointer::json_pointer& instance_location, 
+                                                   const Json& instance, 
+                                                   error_reporter& reporter) const override
+        {
+            return rule_->get_default_value(instance_location, instance, reporter);
+        }
+    };
+
+    template <class Json>
+    struct all_of_criterion
+    {
+        static const std::string& key()
+        {
+            static const std::string k("allOf");
+            return k;
+        }
+
+        static bool is_complete(const Json&, 
+                                const jsonpointer::json_pointer& instance_location, 
+                                error_reporter& reporter, 
+                                const collecting_error_reporter& local_reporter, 
+                                std::size_t)
+        {
+            if (!local_reporter.errors.empty())
+                reporter.error(validation_output("allOf", 
+                                                 "",
+                                                 instance_location.to_uri_fragment(), 
+                                                 "At least one schema failed to match, but all are required to match. ", 
+                                                 local_reporter.errors));
+            return !local_reporter.errors.empty();
+        }
+    };
+
+    template <class Json>
+    struct any_of_criterion
+    {
+        static const std::string& key()
+        {
+            static const std::string k("anyOf");
+            return k;
+        }
+
+        static bool is_complete(const Json&, 
+                                const jsonpointer::json_pointer&, 
+                                error_reporter&, 
+                                const collecting_error_reporter&, 
+                                std::size_t count)
+        {
+            return count == 1;
+        }
+    };
+
+    template <class Json>
+    struct one_of_criterion
+    {
+        static const std::string& key()
+        {
+            static const std::string k("oneOf");
+            return k;
+        }
+
+        static bool is_complete(const Json&, 
+                                const jsonpointer::json_pointer& instance_location, 
+                                error_reporter& reporter, 
+                                const collecting_error_reporter&, 
+                                std::size_t count)
+        {
+            if (count > 1)
+            {
+                std::string message(std::to_string(count));
+                message.append(" subschemas matched, but exactly one is required to match");
+                reporter.error(validation_output("oneOf", 
+                                                 "", 
+                                                 instance_location.to_uri_fragment(), 
+                                                 std::move(message)));
+            }
+            return count > 1;
+        }
+    };
+
+    template <class Json,class Criterion>
+    class combining_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        std::vector<validator_pointer> subschemas_;
+
+    public:
+        combining_validator(abstract_keyword_validator_factory<Json>* builder,
+                            const Json& sch,
+                            const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+            size_t c = 0;
+            for (const auto& subsch : sch.array_range())
+            {
+                subschemas_.push_back(builder->make_keyword_validator(subsch, uris, {Criterion::key(), std::to_string(c++)}));
+            }
+
+            // Validate value of allOf, anyOf, and oneOf "MUST be a non-empty array"
+        }
+
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const final
+        {
+            size_t count = 0;
+
+            collecting_error_reporter local_reporter;
+            for (auto& s : subschemas_) 
+            {
+                std::size_t mark = local_reporter.errors.size();
+                s->validate(instance, instance_location, local_reporter, patch);
+                if (mark == local_reporter.errors.size())
+                    count++;
+
+                if (Criterion::is_complete(instance, instance_location, reporter, local_reporter, count))
+                    return;
+            }
+
+            if (count == 0)
+            {
+                reporter.error(validation_output("combined", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "No schema matched, but one of them is required to match", 
+                                                 local_reporter.errors));
+            }
+        }
+    };
+
+    template <class T, class Json>
+    T get_number(const Json& val, const string_view& keyword) 
+    {
+        if (!val.is_number())
+        {
+            std::string message(keyword);
+            message.append(" must be a number value");
+            JSONCONS_THROW(schema_error(message));
+        }
+        return val.template as<T>();
+    }
+
+    template <class Json,class T>
+    class numeric_validator_base : public keyword_validator<Json>
+    {
+        jsoncons::optional<T> maximum_;
+        std::string absolute_maximum_location_;
+        jsoncons::optional<T> minimum_;
+        std::string absolute_minimum_location_;
+        jsoncons::optional<T> exclusive_maximum_;
+        std::string absolute_exclusive_maximum_location_;
+        jsoncons::optional<T> exclusive_minimum_;
+        std::string absolute_exclusive_minimum_location_;
+        jsoncons::optional<double> multiple_of_;
+        std::string absolute_multiple_of_location_;
+
+    public:
+        numeric_validator_base(const Json& sch, 
+                    const std::vector<schema_location>& uris, 
+                    std::set<std::string>& keywords)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), 
+              maximum_(), minimum_(),exclusive_maximum_(), exclusive_minimum_(), multiple_of_()
+        {
+            auto it = sch.find("maximum");
+            if (it != sch.object_range().end()) 
+            {
+                maximum_ = get_number<T>(it->value(), "maximum");
+                absolute_maximum_location_ = make_absolute_keyword_location(uris,"maximum");
+                keywords.insert("maximum");
+            }
+
+            it = sch.find("minimum");
+            if (it != sch.object_range().end()) 
+            {
+                minimum_ = get_number<T>(it->value(), "minimum");
+                absolute_minimum_location_ = make_absolute_keyword_location(uris,"minimum");
+                keywords.insert("minimum");
+            }
+
+            it = sch.find("exclusiveMaximum");
+            if (it != sch.object_range().end()) 
+            {
+                exclusive_maximum_ = get_number<T>(it->value(), "exclusiveMaximum");
+                absolute_exclusive_maximum_location_ = make_absolute_keyword_location(uris,"exclusiveMaximum");
+                keywords.insert("exclusiveMaximum");
+            }
+
+            it = sch.find("exclusiveMinimum");
+            if (it != sch.object_range().end()) 
+            {
+                exclusive_minimum_ = get_number<T>(it->value(), "exclusiveMinimum");
+                absolute_exclusive_minimum_location_ = make_absolute_keyword_location(uris,"exclusiveMinimum");
+                keywords.insert("exclusiveMinimum");
+            }
+
+            it = sch.find("multipleOf");
+            if (it != sch.object_range().end()) 
+            {
+                multiple_of_ = get_number<double>(it->value(), "multipleOf");
+                absolute_multiple_of_location_ = make_absolute_keyword_location(uris,"multipleOf");
+                keywords.insert("multipleOf");
+            }
+        }
+
+    protected:
+
+        void apply_kewords(T value,
+                           const jsonpointer::json_pointer& instance_location, 
+                           const Json& instance, 
+                           error_reporter& reporter) const 
+        {
+            if (multiple_of_ && value != 0) // exclude zero
+            {
+                if (!is_multiple_of(value, *multiple_of_))
+                {
+                    reporter.error(validation_output("multipleOf", 
+                                                     absolute_multiple_of_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " is not a multiple of " + std::to_string(*multiple_of_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (maximum_)
+            {
+                if (value > *maximum_)
+                {
+                    reporter.error(validation_output("maximum", 
+                                                     absolute_maximum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " exceeds maximum of " + std::to_string(*maximum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (minimum_)
+            {
+                if (value < *minimum_)
+                {
+                    reporter.error(validation_output("minimum", 
+                                                     absolute_minimum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " is below minimum of " + std::to_string(*minimum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (exclusive_maximum_)
+            {
+                if (value >= *exclusive_maximum_)
+                {
+                    reporter.error(validation_output("exclusiveMaximum", 
+                                                     absolute_exclusive_maximum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " exceeds maximum of " + std::to_string(*exclusive_maximum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (exclusive_minimum_)
+            {
+                if (value <= *exclusive_minimum_)
+                {
+                    reporter.error(validation_output("exclusiveMinimum", 
+                                                     absolute_exclusive_minimum_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     instance.template as<std::string>() + " is below minimum of " + std::to_string(*exclusive_minimum_)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+        }
+    private:
+        static bool is_multiple_of(T x, double multiple_of) 
+        {
+            double rem = std::remainder(x, multiple_of);
+            double eps = std::nextafter(x, 0) - x;
+            return std::fabs(rem) < std::fabs(eps);
+        }
+    };
+
+    template <class Json>
+    class integer_validator : public numeric_validator_base<Json,int64_t>
+    {
+    public:
+        integer_validator(const Json& sch, 
+                          const std::vector<schema_location>& uris, 
+                          std::set<std::string>& keywords)
+            : numeric_validator_base<Json, int64_t>(sch, uris, keywords)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const 
+        {
+            if (!(instance.template is_integer<int64_t>() || (instance.is_double() && static_cast<double>(instance.template as<int64_t>()) == instance.template as<double>())))
+            {
+                reporter.error(validation_output("integer", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance is not an integer"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+            int64_t value = instance.template as<int64_t>(); 
+            this->apply_kewords(value, instance_location, instance, reporter);
+        }
+    };
+
+    template <class Json>
+    class number_validator : public numeric_validator_base<Json,double>
+    {
+    public:
+        number_validator(const Json& sch,
+                          const std::vector<schema_location>& uris, 
+                          std::set<std::string>& keywords)
+            : numeric_validator_base<Json, double>(sch, uris, keywords)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const 
+        {
+            if (!(instance.template is_integer<int64_t>() || instance.is_double()))
+            {
+                reporter.error(validation_output("number", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance is not a number"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+            double value = instance.template as<double>(); 
+            this->apply_kewords(value, instance_location, instance, reporter);
+        }
+    };
+
+    // null_validator
+
+    template <class Json>
+    class null_validator : public keyword_validator<Json>
+    {
+    public:
+        null_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const override
+        {
+            if (!instance.is_null())
+            {
+                reporter.error(validation_output("null", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Expected to be null"));
+            }
+        }
+    };
+
+    template <class Json>
+    class boolean_validator : public keyword_validator<Json>
+    {
+    public:
+        boolean_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json&, 
+                         const jsonpointer::json_pointer&, 
+                         error_reporter&, 
+                         Json&) const override
+        {
+        }
+
+    };
+
+    template <class Json>
+    class true_validator : public keyword_validator<Json>
+    {
+    public:
+        true_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json&, 
+                         const jsonpointer::json_pointer&, 
+                         error_reporter&, 
+                         Json&) const override
+        {
+        }
+    };
+
+    template <class Json>
+    class false_validator : public keyword_validator<Json>
+    {
+    public:
+        false_validator(const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : "")
+        {
+        }
+    private:
+        void do_validate(const Json&, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const override
+        {
+            reporter.error(validation_output("false", 
+                                             this->absolute_keyword_location(), 
+                                             instance_location.to_uri_fragment(), 
+                                             "False schema always fails"));
+        }
+    };
+
+    template <class Json>
+    class required_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        std::vector<std::string> items_;
+
+    public:
+        required_validator(const std::vector<schema_location>& uris,
+                         const std::vector<std::string>& items)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), items_(items) {}
+        required_validator(const std::string& absolute_keyword_location, const std::vector<std::string>& items)
+            : keyword_validator<Json>(absolute_keyword_location), items_(items) {}
+
+        required_validator(const required_validator&) = delete;
+        required_validator(required_validator&&) = default;
+        required_validator& operator=(const required_validator&) = delete;
+        required_validator& operator=(required_validator&&) = default;
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json&) const override final
+        {
+            for (const auto& key : items_)
+            {
+                if (instance.find(key) == instance.object_range().end())
+                {
+                    reporter.error(validation_output("required", 
+                                                     this->absolute_keyword_location(), 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "Required property \"" + key + "\" not found"));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+        }
+    };
+
+    template <class Json>
+    class object_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        jsoncons::optional<std::size_t> max_properties_;
+        std::string absolute_max_properties_location_;
+        jsoncons::optional<std::size_t> min_properties_;
+        std::string absolute_min_properties_location_;
+        jsoncons::optional<required_validator<Json>> required_;
+
+        std::map<std::string, validator_pointer> properties_;
+    #if defined(JSONCONS_HAS_STD_REGEX)
+        std::vector<std::pair<std::regex, validator_pointer>> pattern_properties_;
+    #endif
+        validator_pointer additional_properties_;
+
+        std::map<std::string, validator_pointer> dependencies_;
+
+        validator_pointer property_name_validator_;
+
+    public:
+        object_validator(abstract_keyword_validator_factory<Json>* builder,
+                    const Json& sch,
+                    const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), 
+              max_properties_(), min_properties_(), 
+              additional_properties_(nullptr),
+              property_name_validator_(nullptr)
+        {
+            auto it = sch.find("maxProperties");
+            if (it != sch.object_range().end()) 
+            {
+                max_properties_ = it->value().template as<std::size_t>();
+                absolute_max_properties_location_ = make_absolute_keyword_location(uris, "maxProperties");
+            }
+
+            it = sch.find("minProperties");
+            if (it != sch.object_range().end()) 
+            {
+                min_properties_ = it->value().template as<std::size_t>();
+                absolute_min_properties_location_ = make_absolute_keyword_location(uris, "minProperties");
+            }
+
+            it = sch.find("required");
+            if (it != sch.object_range().end()) 
+            {
+                auto location = make_absolute_keyword_location(uris, "required");
+                required_ = required_validator<Json>(location, 
+                                                   it->value().template as<std::vector<std::string>>());
+            }
+
+            it = sch.find("properties");
+            if (it != sch.object_range().end()) 
+            {
+                for (const auto& prop : it->value().object_range())
+                    properties_.emplace(
+                        std::make_pair(
+                            prop.key(),
+                            builder->make_keyword_validator(prop.value(), uris, {"properties", prop.key()})));
+            }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+            it = sch.find("patternProperties");
+            if (it != sch.object_range().end()) 
+            {
+                for (const auto& prop : it->value().object_range())
+                    pattern_properties_.emplace_back(
+                        std::make_pair(
+                            std::regex(prop.key(), std::regex::ECMAScript),
+                            builder->make_keyword_validator(prop.value(), uris, {prop.key()})));
+            }
+    #endif
+
+            it = sch.find("additionalProperties");
+            if (it != sch.object_range().end()) 
+            {
+                additional_properties_ = builder->make_keyword_validator(it->value(), uris, {"additionalProperties"});
+            }
+
+            it = sch.find("dependencies");
+            if (it != sch.object_range().end()) 
+            {
+                for (const auto& dep : it->value().object_range())
+                {
+                    switch (dep.value().type()) 
+                    {
+                        case json_type::array_value:
+                        {
+                            auto location = make_absolute_keyword_location(uris, "dependencies");
+                            dependencies_.emplace(dep.key(),
+                                                  builder->make_required_validator({location},
+                                                                                 dep.value().template as<std::vector<std::string>>()));
+                            break;
+                        }
+                        default:
+                        {
+                            dependencies_.emplace(dep.key(),
+                                                  builder->make_keyword_validator(dep.value(), uris, {"dependencies", dep.key()}));
+                            break;
+                        }
+                    }
+                }
+            }
+
+            auto property_names_it = sch.find("propertyNames");
+            if (property_names_it != sch.object_range().end()) 
+            {
+                property_name_validator_ = builder->make_keyword_validator(property_names_it->value(), uris, {"propertyNames"});
+            }
+        }
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const override
+        {
+            if (max_properties_ && instance.size() > *max_properties_)
+            {
+                std::string message("Maximum properties: " + std::to_string(*max_properties_));
+                message.append(", found: " + std::to_string(instance.size()));
+                reporter.error(validation_output("maxProperties", 
+                                                 absolute_max_properties_location_, 
+                                                 instance_location.to_uri_fragment(), 
+                                                 std::move(message)));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (min_properties_ && instance.size() < *min_properties_)
+            {
+                std::string message("Minimum properties: " + std::to_string(*min_properties_));
+                message.append(", found: " + std::to_string(instance.size()));
+                reporter.error(validation_output("minProperties", 
+                                                 absolute_min_properties_location_, 
+                                                 instance_location.to_uri_fragment(), 
+                                                 std::move(message)));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (required_)
+                required_->validate(instance, instance_location, reporter, patch);
+
+            for (const auto& property : instance.object_range()) 
+            {
+                if (property_name_validator_)
+                    property_name_validator_->validate(property.key(), instance_location, reporter, patch);
+
+                bool a_prop_or_pattern_matched = false;
+                auto properties_it = properties_.find(property.key());
+
+                // check if it is in "properties"
+                if (properties_it != properties_.end()) 
+                {
+                    a_prop_or_pattern_matched = true;
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= property.key();
+                    properties_it->second->validate(property.value(), pointer, reporter, patch);
+                }
+
+    #if defined(JSONCONS_HAS_STD_REGEX)
+
+                // check all matching "patternProperties"
+                for (auto& schema_pp : pattern_properties_)
+                    if (std::regex_search(property.key(), schema_pp.first)) 
+                    {
+                        a_prop_or_pattern_matched = true;
+                        jsonpointer::json_pointer pointer(instance_location);
+                        pointer /= property.key();
+                        schema_pp.second->validate(property.value(), pointer, reporter, patch);
+                    }
+    #endif
+
+                // finally, check "additionalProperties" 
+                if (!a_prop_or_pattern_matched && additional_properties_) 
+                {
+                    collecting_error_reporter local_reporter;
+
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= property.key();
+                    additional_properties_->validate(property.value(), pointer, local_reporter, patch);
+                    if (!local_reporter.errors.empty())
+                    {
+                        reporter.error(validation_output("additionalProperties", 
+                                                         additional_properties_->absolute_keyword_location(), 
+                                                         instance_location.to_uri_fragment(), 
+                                                         "Additional property \"" + property.key() + "\" found but was invalid."));
+                        if (reporter.fail_early())
+                        {
+                            return;
+                        }
+                    }
+                }
+            }
+
+            // reverse search
+            for (auto const& prop : properties_) 
+            {
+                const auto finding = instance.find(prop.first);
+                if (finding == instance.object_range().end()) 
+                { 
+                    // If property is not in instance
+                    auto default_value = prop.second->get_default_value(instance_location, instance, reporter);
+                    if (default_value) 
+                    { 
+                        // If default value is available, update patch
+                        jsonpointer::json_pointer pointer(instance_location);
+                        pointer /= prop.first;
+
+                        update_patch(patch, pointer, std::move(*default_value));
+                    }
+                }
+            }
+
+            for (const auto& dep : dependencies_) 
+            {
+                auto prop = instance.find(dep.first);
+                if (prop != instance.object_range().end()) 
+                {
+                    // if dependency-property is present in instance
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= dep.first;
+                    dep.second->validate(instance, pointer, reporter, patch); // validate
+                }
+            }
+        }
+
+        void update_patch(Json& patch, const jsonpointer::json_pointer& instance_location, Json&& default_value) const
+        {
+            Json j;
+            j.try_emplace("op", "add"); 
+            j.try_emplace("path", instance_location.to_uri_fragment()); 
+            j.try_emplace("value", std::forward<Json>(default_value)); 
+            patch.push_back(std::move(j));
+        }
+    };
+
+    // array_validator
+
+    template <class Json>
+    class array_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        jsoncons::optional<std::size_t> max_items_;
+        std::string absolute_max_items_location_;
+        jsoncons::optional<std::size_t> min_items_;
+        std::string absolute_min_items_location_;
+        bool unique_items_ = false;
+        validator_pointer items_validator_;
+        std::vector<validator_pointer> item_validators_;
+        validator_pointer additional_items_validator_;
+        validator_pointer contains_validator_;
+
+    public:
+        array_validator(abstract_keyword_validator_factory<Json>* builder, 
+                   const Json& sch, 
+                   const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), 
+              max_items_(), min_items_(), items_validator_(nullptr), additional_items_validator_(nullptr), contains_validator_(nullptr)
+        {
+            {
+                auto it = sch.find("maxItems");
+                if (it != sch.object_range().end()) 
+                {
+                    max_items_ = it->value().template as<std::size_t>();
+                    absolute_max_items_location_ = make_absolute_keyword_location(uris, "maxItems");
+                }
+            }
+
+            {
+                auto it = sch.find("minItems");
+                if (it != sch.object_range().end()) 
+                {
+                    min_items_ = it->value().template as<std::size_t>();
+                    absolute_min_items_location_ = make_absolute_keyword_location(uris, "minItems");
+                }
+            }
+
+            {
+                auto it = sch.find("uniqueItems");
+                if (it != sch.object_range().end()) 
+                {
+                    unique_items_ = it->value().template as<bool>();
+                }
+            }
+
+            {
+                auto it = sch.find("items");
+                if (it != sch.object_range().end()) 
+                {
+
+                    if (it->value().type() == json_type::array_value) 
+                    {
+                        size_t c = 0;
+                        for (const auto& subsch : it->value().array_range())
+                            item_validators_.push_back(builder->make_keyword_validator(subsch, uris, {"items", std::to_string(c++)}));
+
+                        auto attr_add = sch.find("additionalItems");
+                        if (attr_add != sch.object_range().end()) 
+                        {
+                            additional_items_validator_ = builder->make_keyword_validator(attr_add->value(), uris, {"additionalItems"});
+                        }
+
+                    } 
+                    else if (it->value().type() == json_type::object_value ||
+                               it->value().type() == json_type::bool_value)
+                    {
+                        items_validator_ = builder->make_keyword_validator(it->value(), uris, {"items"});
+                    }
+
+                }
+            }
+
+            {
+                auto it = sch.find("contains");
+                if (it != sch.object_range().end()) 
+                {
+                    contains_validator_ = builder->make_keyword_validator(it->value(), uris, {"contains"});
+                }
+            }
+        }
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const override
+        {
+            if (max_items_)
+            {
+                if (instance.size() > *max_items_)
+                {
+                    std::string message("Expected maximum item count: " + std::to_string(*max_items_));
+                    message.append(", found: " + std::to_string(instance.size()));
+                    reporter.error(validation_output("maxItems", 
+                                                     absolute_max_items_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::move(message)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (min_items_)
+            {
+                if (instance.size() < *min_items_)
+                {
+                    std::string message("Expected minimum item count: " + std::to_string(*min_items_));
+                    message.append(", found: " + std::to_string(instance.size()));
+                    reporter.error(validation_output("minItems", 
+                                                     absolute_min_items_location_, 
+                                                     instance_location.to_uri_fragment(), 
+                                                     std::move(message)));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            if (unique_items_) 
+            {
+                if (!array_has_unique_items(instance))
+                {
+                    reporter.error(validation_output("uniqueItems", 
+                                                     this->absolute_keyword_location(), 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "Array items are not unique"));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+
+            size_t index = 0;
+            if (items_validator_)
+            {
+                for (const auto& i : instance.array_range()) 
+                {
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= index;
+                    items_validator_->validate(i, pointer, reporter, patch);
+                    index++;
+                }
+            }
+            else 
+            {
+                auto validator_it = item_validators_.cbegin();
+                for (const auto& item : instance.array_range()) 
+                {
+                    validator_pointer item_validator = nullptr;
+                    if (validator_it != item_validators_.cend())
+                    {
+                        item_validator = *validator_it;
+                        ++validator_it;
+                    }
+                    else if (additional_items_validator_ != nullptr)
+                    {
+                        item_validator = additional_items_validator_;
+                    }
+                    else
+                        break;
+
+                    jsonpointer::json_pointer pointer(instance_location);
+                    pointer /= index;
+                    item_validator->validate(item, pointer, reporter, patch);
+                }
+            }
+
+            if (contains_validator_) 
+            {
+                bool contained = false;
+                collecting_error_reporter local_reporter;
+                for (const auto& item : instance.array_range()) 
+                {
+                    std::size_t mark = local_reporter.errors.size();
+                    contains_validator_->validate(item, instance_location, local_reporter, patch);
+                    if (mark == local_reporter.errors.size()) 
+                    {
+                        contained = true;
+                        break;
+                    }
+                }
+                if (!contained)
+                {
+                    reporter.error(validation_output("contains", 
+                                                     this->absolute_keyword_location(), 
+                                                     instance_location.to_uri_fragment(), 
+                                                     "Expected at least one array item to match \"contains\" schema", 
+                                                     local_reporter.errors));
+                    if (reporter.fail_early())
+                    {
+                        return;
+                    }
+                }
+            }
+        }
+
+        static bool array_has_unique_items(const Json& a) 
+        {
+            for (auto it = a.array_range().begin(); it != a.array_range().end(); ++it) 
+            {
+                for (auto jt = it+1; jt != a.array_range().end(); ++jt) 
+                {
+                    if (*it == *jt) 
+                    {
+                        return false; // contains duplicates 
+                    }
+                }
+            }
+            return true; // elements are unique
+        }
+    };
+
+    template <class Json>
+    class conditional_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        validator_pointer if_validator_;
+        validator_pointer then_validator_;
+        validator_pointer else_validator_;
+
+    public:
+        conditional_validator(abstract_keyword_validator_factory<Json>* builder,
+                         const Json& sch_if,
+                         const Json& sch,
+                         const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), if_validator_(nullptr), then_validator_(nullptr), else_validator_(nullptr)
+        {
+            auto then_it = sch.find("then");
+            auto else_it = sch.find("else");
+
+            if (then_it != sch.object_range().end() || else_it != sch.object_range().end()) 
+            {
+                if_validator_ = builder->make_keyword_validator(sch_if, uris, {"if"});
+
+                if (then_it != sch.object_range().end()) 
+                {
+                    then_validator_ = builder->make_keyword_validator(then_it->value(), uris, {"then"});
+                }
+
+                if (else_it != sch.object_range().end()) 
+                {
+                    else_validator_ = builder->make_keyword_validator(else_it->value(), uris, {"else"});
+                }
+            }
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const final
+        {
+            if (if_validator_) 
+            {
+                collecting_error_reporter local_reporter;
+
+                if_validator_->validate(instance, instance_location, local_reporter, patch);
+                if (local_reporter.errors.empty()) 
+                {
+                    if (then_validator_)
+                        then_validator_->validate(instance, instance_location, reporter, patch);
+                } 
+                else 
+                {
+                    if (else_validator_)
+                        else_validator_->validate(instance, instance_location, reporter, patch);
+                }
+            }
+        }
+    };
+
+    // enum_validator
+
+    template <class Json>
+    class enum_validator : public keyword_validator<Json>
+    {
+        Json enum_validator_;
+
+    public:
+        enum_validator(const Json& sch,
+                  const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), enum_validator_(sch)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter,
+                         Json&) const final
+        {
+            bool in_range = false;
+            for (const auto& item : enum_validator_.array_range())
+            {
+                if (item == instance) 
+                {
+                    in_range = true;
+                    break;
+                }
+            }
+
+            if (!in_range)
+            {
+                reporter.error(validation_output("enum", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 instance.template as<std::string>() + " is not a valid enum value"));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+        }
+    };
+
+    // const_keyword
+
+    template <class Json>
+    class const_keyword : public keyword_validator<Json>
+    {
+        Json const_validator_;
+
+    public:
+        const_keyword(const Json& sch, const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), const_validator_(sch)
+        {
+        }
+    private:
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter,
+                         Json&) const final
+        {
+            if (const_validator_ != instance)
+                reporter.error(validation_output("const", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 "Instance is not const"));
+        }
+    };
+
+    template <class Json>
+    class type_validator : public keyword_validator<Json>
+    {
+        using validator_pointer = typename keyword_validator<Json>::self_pointer;
+
+        Json default_value_;
+        std::vector<validator_pointer> type_mapping_;
+        jsoncons::optional<enum_validator<Json>> enum_validator_;
+        jsoncons::optional<const_keyword<Json>> const_validator_;
+        std::vector<validator_pointer> combined_validators_;
+        jsoncons::optional<conditional_validator<Json>> conditional_validator_;
+        std::vector<std::string> expected_types_;
+
+    public:
+        type_validator(const type_validator&) = delete;
+        type_validator& operator=(const type_validator&) = delete;
+        type_validator(type_validator&&) = default;
+        type_validator& operator=(type_validator&&) = default;
+
+        type_validator(abstract_keyword_validator_factory<Json>* builder,
+                     const Json& sch,
+                     const std::vector<schema_location>& uris)
+            : keyword_validator<Json>((!uris.empty() && uris.back().is_absolute()) ? uris.back().string() : ""), default_value_(jsoncons::null_type()), 
+              type_mapping_((uint8_t)(json_type::object_value)+1), 
+              enum_validator_(), const_validator_()
+        {
+            //std::cout << uris.size() << " uris: ";
+            //for (const auto& uri : uris)
+            //{
+            //    std::cout << uri.string() << ", ";
+            //}
+            //std::cout << "\n";
+            std::set<std::string> known_keywords;
+
+            auto it = sch.find("type");
+            if (it == sch.object_range().end()) 
+            {
+                initialize_type_mapping(builder, "", sch, uris, known_keywords);
+            }
+            else 
+            {
+                switch (it->value().type()) 
+                { 
+                    case json_type::string_value: 
+                    {
+                        auto type = it->value().template as<std::string>();
+                        initialize_type_mapping(builder, type, sch, uris, known_keywords);
+                        expected_types_.emplace_back(std::move(type));
+                        break;
+                    } 
+
+                    case json_type::array_value: // "type": ["type1", "type2"]
+                    {
+                        for (const auto& item : it->value().array_range())
+                        {
+                            auto type = item.template as<std::string>();
+                            initialize_type_mapping(builder, type, sch, uris, known_keywords);
+                            expected_types_.emplace_back(std::move(type));
+                        }
+                        break;
+                    }
+                    default:
+                        break;
+                }
+            }
+
+            const auto default_it = sch.find("default");
+            if (default_it != sch.object_range().end()) 
+            {
+                default_value_ = default_it->value();
+            }
+
+            it = sch.find("enum");
+            if (it != sch.object_range().end()) 
+            {
+                enum_validator_ = enum_validator<Json >(it->value(), uris);
+            }
+
+            it = sch.find("const");
+            if (it != sch.object_range().end()) 
+            {
+                const_validator_ = const_keyword<Json>(it->value(), uris);
+            }
+
+            it = sch.find("not");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_not_validator(it->value(), uris));
+            }
+
+            it = sch.find("allOf");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_all_of_validator(it->value(), uris));
+            }
+
+            it = sch.find("anyOf");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_any_of_validator(it->value(), uris));
+            }
+
+            it = sch.find("oneOf");
+            if (it != sch.object_range().end()) 
+            {
+                combined_validators_.push_back(builder->make_one_of_validator(it->value(), uris));
+            }
+
+            it = sch.find("if");
+            if (it != sch.object_range().end()) 
+            {
+                conditional_validator_ = conditional_validator<Json>(builder, it->value(), sch, uris);
+            }
+        }
+    private:
+
+        void do_validate(const Json& instance, 
+                         const jsonpointer::json_pointer& instance_location, 
+                         error_reporter& reporter, 
+                         Json& patch) const override final
+        {
+            auto type = type_mapping_[(uint8_t) instance.type()];
+
+            if (type)
+                type->validate(instance, instance_location, reporter, patch);
+            else
+            {
+                std::ostringstream ss;
+                ss << "Expected ";
+                for (std::size_t i = 0; i < expected_types_.size(); ++i)
+                {
+                        if (i > 0)
+                        { 
+                            ss << ", ";
+                            if (i+1 == expected_types_.size())
+                            { 
+                                ss << "or ";
+                            }
+                        }
+                        ss << expected_types_[i];
+                }
+                ss << ", found " << instance.type();
+
+                reporter.error(validation_output("type", 
+                                                 this->absolute_keyword_location(), 
+                                                 instance_location.to_uri_fragment(), 
+                                                 ss.str()));
+                if (reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (enum_validator_)
+            { 
+                enum_validator_->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            if (const_validator_)
+            { 
+                const_validator_->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+            for (const auto& validator : combined_validators_)
+            {
+                validator->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+
+
+            if (conditional_validator_)
+            { 
+                conditional_validator_->validate(instance, instance_location, reporter, patch);
+                if (reporter.error_count() > 0 && reporter.fail_early())
+                {
+                    return;
+                }
+            }
+        }
+
+        jsoncons::optional<Json> get_default_value(const jsonpointer::json_pointer&, 
+                                                   const Json&,
+                                                   error_reporter&) const override
+        {
+            return default_value_;
+        }
+
+        void initialize_type_mapping(abstract_keyword_validator_factory<Json>* builder,
+                                     const std::string& type,
+                                     const Json& sch,
+                                     const std::vector<schema_location>& uris,
+                                     std::set<std::string>& keywords)
+        {
+            if (type == "null")
+            {
+                type_mapping_[(uint8_t)json_type::null_value] = builder->make_null_validator(uris);
+            }
+            else if (type == "object")
+            {
+                type_mapping_[(uint8_t)json_type::object_value] = builder->make_object_validator(sch, uris);
+            }
+            else if (type == "array")
+            {
+                type_mapping_[(uint8_t)json_type::array_value] = builder->make_array_validator(sch, uris);
+            }
+            else if (type == "string")
+            {
+                type_mapping_[(uint8_t)json_type::string_value] = builder->make_string_validator(sch, uris);
+                // For binary types
+                type_mapping_[(uint8_t) json_type::byte_string_value] = type_mapping_[(uint8_t) json_type::string_value];
+            }
+            else if (type == "boolean")
+            {
+                type_mapping_[(uint8_t)json_type::bool_value] = builder->make_boolean_validator(uris);
+            }
+            else if (type == "integer")
+            {
+                type_mapping_[(uint8_t)json_type::int64_value] = builder->make_integer_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::int64_value];
+                type_mapping_[(uint8_t)json_type::double_value] = type_mapping_[(uint8_t)json_type::int64_value];
+            }
+            else if (type == "number")
+            {
+                type_mapping_[(uint8_t)json_type::double_value] = builder->make_number_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::int64_value] = type_mapping_[(uint8_t)json_type::double_value];
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::double_value];
+            }
+            else if (type.empty())
+            {
+                type_mapping_[(uint8_t)json_type::null_value] = builder->make_null_validator(uris);
+                type_mapping_[(uint8_t)json_type::object_value] = builder->make_object_validator(sch, uris);
+                type_mapping_[(uint8_t)json_type::array_value] = builder->make_array_validator(sch, uris);
+                type_mapping_[(uint8_t)json_type::string_value] = builder->make_string_validator(sch, uris);
+                // For binary types
+                type_mapping_[(uint8_t) json_type::byte_string_value] = type_mapping_[(uint8_t) json_type::string_value];
+                type_mapping_[(uint8_t)json_type::bool_value] = builder->make_boolean_validator(uris);
+                type_mapping_[(uint8_t)json_type::int64_value] = builder->make_integer_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::int64_value];
+                type_mapping_[(uint8_t)json_type::double_value] = type_mapping_[(uint8_t)json_type::int64_value];
+                type_mapping_[(uint8_t)json_type::double_value] = builder->make_number_validator(sch, uris, keywords);
+                type_mapping_[(uint8_t)json_type::int64_value] = type_mapping_[(uint8_t)json_type::double_value];
+                type_mapping_[(uint8_t)json_type::uint64_value] = type_mapping_[(uint8_t)json_type::double_value];
+            }
+        }
+    };
+
+} // namespace jsonschema
+} // namespace jsoncons
+
+#endif // JSONCONS_JSONSCHEMA_VALUE_RULES_HPP