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1 files changed, 1322 insertions, 0 deletions

diff --git a/llama.cpp/common/jinja/value.cpp b/llama.cpp/common/jinja/value.cpp
new file mode 100644
index 0000000..2aa156b
--- /dev/null
+++ b/llama.cpp/common/jinja/value.cpp
@@ -0,0 +1,1322 @@
+#include "runtime.h"
+#include "value.h"
+
+// for converting from JSON to jinja values
+#include <nlohmann/json.hpp>
+
+#include <string>
+#include <cctype>
+#include <vector>
+#include <optional>
+#include <algorithm>
+
+#define FILENAME "jinja-value"
+
+namespace jinja {
+
+// func_args method implementations
+
+value func_args::get_kwarg(const std::string & key, value default_val) const {
+    for (const auto & arg : args) {
+        if (is_val<value_kwarg>(arg)) {
+            auto * kwarg = cast_val<value_kwarg>(arg);
+            if (kwarg->key == key) {
+                return kwarg->val;
+            }
+        }
+    }
+    return default_val;
+}
+
+value func_args::get_kwarg_or_pos(const std::string & key, size_t pos) const {
+    value val = get_kwarg(key, mk_val<value_undefined>());
+
+    if (val->is_undefined() && pos < count() && !is_val<value_kwarg>(args[pos])) {
+        return args[pos];
+    }
+
+    return val;
+}
+
+value func_args::get_pos(size_t pos) const {
+    if (count() > pos) {
+        return args[pos];
+    }
+    throw raised_exception("Function '" + func_name + "' expected at least " + std::to_string(pos + 1) + " arguments, got " + std::to_string(count()));
+}
+
+value func_args::get_pos(size_t pos, value default_val) const {
+    if (count() > pos) {
+        return args[pos];
+    }
+    return default_val;
+}
+
+void func_args::push_back(const value & val) {
+    args.push_back(val);
+}
+
+void func_args::push_front(const value & val) {
+    args.insert(args.begin(), val);
+}
+
+const std::vector<value> & func_args::get_args() const {
+    return args;
+}
+
+/**
+ * Function that mimics Python's array slicing.
+ */
+template<typename T>
+static T slice(const T & array, int64_t start, int64_t stop, int64_t step = 1) {
+    int64_t len = static_cast<int64_t>(array.size());
+    int64_t direction = (step > 0) ? 1 : ((step < 0) ? -1 : 0);
+    int64_t start_val = 0;
+    int64_t stop_val = 0;
+    if (direction >= 0) {
+        start_val = start;
+        if (start_val < 0) {
+            start_val = std::max(len + start_val, (int64_t)0);
+        } else {
+            start_val = std::min(start_val, len);
+        }
+
+        stop_val = stop;
+        if (stop_val < 0) {
+            stop_val = std::max(len + stop_val, (int64_t)0);
+        } else {
+            stop_val = std::min(stop_val, len);
+        }
+    } else {
+        start_val = len - 1;
+        if (start_val < 0) {
+            start_val = std::max(len + start_val, (int64_t)-1);
+        } else {
+            start_val = std::min(start_val, len - 1);
+        }
+
+        stop_val = -1;
+        if (stop_val < -1) {
+            stop_val = std::max(len + stop_val, (int64_t)-1);
+        } else {
+            stop_val = std::min(stop_val, len - 1);
+        }
+    }
+    T result;
+    if (direction == 0) {
+        return result;
+    }
+    for (int64_t i = start_val; direction * i < direction * stop_val; i += step) {
+        if (i >= 0 && i < len) {
+            result.push_back(array[static_cast<size_t>(i)]);
+        }
+    }
+    return result;
+}
+
+template<typename T>
+static value empty_value_fn(const func_args &) {
+    if constexpr (std::is_same_v<T, value_int>) {
+        return mk_val<T>(0);
+    } else if constexpr (std::is_same_v<T, value_float>) {
+        return mk_val<T>(0.0);
+    } else if constexpr (std::is_same_v<T, value_bool>) {
+        return mk_val<T>(false);
+    } else {
+        return mk_val<T>();
+    }
+}
+template<typename T>
+static value test_type_fn(const func_args & args) {
+    args.ensure_count(1);
+    bool is_type = is_val<T>(args.get_pos(0));
+    JJ_DEBUG("test_type_fn: type=%s result=%d", typeid(T).name(), is_type ? 1 : 0);
+    return mk_val<value_bool>(is_type);
+}
+template<typename T, typename U>
+static value test_type_fn(const func_args & args) {
+    args.ensure_count(1);
+    bool is_type = is_val<T>(args.get_pos(0)) || is_val<U>(args.get_pos(0));
+    JJ_DEBUG("test_type_fn: type=%s or %s result=%d", typeid(T).name(), typeid(U).name(), is_type ? 1 : 0);
+    return mk_val<value_bool>(is_type);
+}
+template<typename T, typename U, typename V>
+static value test_type_fn(const func_args & args) {
+    args.ensure_count(1);
+    bool is_type = is_val<T>(args.get_pos(0)) || is_val<U>(args.get_pos(0)) || is_val<V>(args.get_pos(0));
+    JJ_DEBUG("test_type_fn: type=%s, %s or %s result=%d", typeid(T).name(), typeid(U).name(), typeid(V).name(), is_type ? 1 : 0);
+    return mk_val<value_bool>(is_type);
+}
+template<value_compare_op op>
+static value test_compare_fn(const func_args & args) {
+    args.ensure_count(2, 2);
+    return mk_val<value_bool>(value_compare(args.get_pos(0), args.get_pos(1), op));
+}
+
+static value tojson(const func_args & args) {
+    args.ensure_count(1, 5);
+    value val_ascii      = args.get_kwarg_or_pos("ensure_ascii", 1);
+    value val_indent     = args.get_kwarg_or_pos("indent",       2);
+    value val_separators = args.get_kwarg_or_pos("separators",   3);
+    value val_sort       = args.get_kwarg_or_pos("sort_keys",    4);
+    int indent = -1;
+    if (is_val<value_int>(val_indent)) {
+        indent = static_cast<int>(val_indent->as_int());
+    }
+    if (val_ascii->as_bool()) { // undefined == false
+        throw not_implemented_exception("tojson ensure_ascii=true not implemented");
+    }
+    if (val_sort->as_bool()) { // undefined == false
+        throw not_implemented_exception("tojson sort_keys=true not implemented");
+    }
+    auto separators = (is_val<value_array>(val_separators) ? val_separators : mk_val<value_array>())->as_array();
+    std::string item_sep = separators.size() > 0 ? separators[0]->as_string().str() : (indent < 0 ? ", " : ",");
+    std::string key_sep = separators.size() > 1 ? separators[1]->as_string().str() : ": ";
+    std::string json_str = value_to_json(args.get_pos(0), indent, item_sep, key_sep);
+    return mk_val<value_string>(json_str);
+}
+
+template<bool is_reject>
+static value selectattr(const func_args & args) {
+    args.ensure_count(2, 4);
+    args.ensure_vals<value_array, value_string, value_string, value_string>(true, true, false, false);
+
+    auto arr = args.get_pos(0)->as_array();
+    auto attribute = args.get_pos(1);
+    auto out = mk_val<value_array>();
+    value val_default = mk_val<value_undefined>();
+
+    if (args.count() == 2) {
+        // example: array | selectattr("active")
+        for (const auto & item : arr) {
+            if (!is_val<value_object>(item)) {
+                throw raised_exception("selectattr: item is not an object");
+            }
+            value attr_val = item->at(attribute, val_default);
+            bool is_selected = attr_val->as_bool();
+            if constexpr (is_reject) is_selected = !is_selected;
+            if (is_selected) out->push_back(item);
+        }
+        return out;
+
+    } else if (args.count() == 3) {
+        // example: array | selectattr("equalto", "text")
+        // translated to: test_is_equalto(item, "text")
+        std::string test_name = args.get_pos(1)->as_string().str();
+        value test_val = args.get_pos(2);
+        auto & builtins = global_builtins();
+        auto it = builtins.find("test_is_" + test_name);
+        if (it == builtins.end()) {
+            throw raised_exception("selectattr: unknown test '" + test_name + "'");
+        }
+        auto test_fn = it->second;
+        for (const auto & item : arr) {
+            func_args test_args(args.ctx);
+            test_args.push_back(item); // current object
+            test_args.push_back(test_val); // extra argument
+            value test_result = test_fn(test_args);
+            bool is_selected = test_result->as_bool();
+            if constexpr (is_reject) is_selected = !is_selected;
+            if (is_selected) out->push_back(item);
+        }
+        return out;
+
+    } else if (args.count() == 4) {
+        // example: array | selectattr("status", "equalto", "active")
+        // translated to: test_is_equalto(item.status, "active")
+        std::string test_name = args.get_pos(2)->as_string().str();
+        auto extra_arg = args.get_pos(3);
+        auto & builtins = global_builtins();
+        auto it = builtins.find("test_is_" + test_name);
+        if (it == builtins.end()) {
+            throw raised_exception("selectattr: unknown test '" + test_name + "'");
+        }
+        auto test_fn = it->second;
+        for (const auto & item : arr) {
+            if (!is_val<value_object>(item)) {
+                throw raised_exception("selectattr: item is not an object");
+            }
+            value attr_val = item->at(attribute, val_default);
+            func_args test_args(args.ctx);
+            test_args.push_back(attr_val); // attribute value
+            test_args.push_back(extra_arg); // extra argument
+            value test_result = test_fn(test_args);
+            bool is_selected = test_result->as_bool();
+            if constexpr (is_reject) is_selected = !is_selected;
+            if (is_selected) out->push_back(item);
+        }
+        return out;
+    } else {
+        throw raised_exception("selectattr: invalid number of arguments");
+    }
+
+    return out;
+}
+
+static value default_value(const func_args & args) {
+    args.ensure_count(2, 3);
+    value val_check = args.get_kwarg_or_pos("boolean", 2);
+    bool check_bool = val_check->as_bool(); // undefined == false
+    bool no_value = check_bool
+        ? (!args.get_pos(0)->as_bool())
+        : (args.get_pos(0)->is_undefined() || args.get_pos(0)->is_none());
+    return no_value ? args.get_pos(1) : args.get_pos(0);
+}
+
+const func_builtins & global_builtins() {
+    static const func_builtins builtins = {
+        {"raise_exception", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            std::string msg = args.get_pos(0)->as_string().str();
+            throw raised_exception("Jinja Exception: " + msg);
+        }},
+        {"namespace", [](const func_args & args) -> value {
+            auto out = mk_val<value_object>();
+            for (const auto & arg : args.get_args()) {
+                if (!is_val<value_kwarg>(arg)) {
+                    throw raised_exception("namespace() arguments must be kwargs");
+                }
+                auto kwarg = cast_val<value_kwarg>(arg);
+                JJ_DEBUG("namespace: adding key '%s'", kwarg->key.c_str());
+                out->insert(kwarg->key, kwarg->val);
+            }
+            return out;
+        }},
+        {"strftime_now", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            std::string format = args.get_pos(0)->as_string().str();
+            // get current time
+            // TODO: make sure this is the same behavior as Python's strftime
+            char buf[100];
+            if (std::strftime(buf, sizeof(buf), format.c_str(), std::localtime(&args.ctx.current_time))) {
+                return mk_val<value_string>(std::string(buf));
+            } else {
+                throw raised_exception("strftime_now: failed to format time");
+            }
+        }},
+        {"range", [](const func_args & args) -> value {
+            args.ensure_count(1, 3);
+            args.ensure_vals<value_int, value_int, value_int>(true, false, false);
+
+            auto arg0 = args.get_pos(0);
+            auto arg1 = args.get_pos(1, mk_val<value_undefined>());
+            auto arg2 = args.get_pos(2, mk_val<value_undefined>());
+
+            int64_t start, stop, step;
+            if (args.count() == 1) {
+                start = 0;
+                stop = arg0->as_int();
+                step = 1;
+            } else if (args.count() == 2) {
+                start = arg0->as_int();
+                stop = arg1->as_int();
+                step = 1;
+            } else {
+                start = arg0->as_int();
+                stop = arg1->as_int();
+                step = arg2->as_int();
+            }
+
+            auto out = mk_val<value_array>();
+            if (step == 0) {
+                throw raised_exception("range() step argument must not be zero");
+            }
+            if (step > 0) {
+                for (int64_t i = start; i < stop; i += step) {
+                    out->push_back(mk_val<value_int>(i));
+                }
+            } else {
+                for (int64_t i = start; i > stop; i += step) {
+                    out->push_back(mk_val<value_int>(i));
+                }
+            }
+            return out;
+        }},
+        {"tojson", tojson},
+
+        // tests
+        {"test_is_boolean", test_type_fn<value_bool>},
+        {"test_is_callable", test_type_fn<value_func>},
+        {"test_is_odd", [](const func_args & args) -> value {
+            args.ensure_vals<value_int>();
+            int64_t val = args.get_pos(0)->as_int();
+            return mk_val<value_bool>(val % 2 != 0);
+        }},
+        {"test_is_even", [](const func_args & args) -> value {
+            args.ensure_vals<value_int>();
+            int64_t val = args.get_pos(0)->as_int();
+            return mk_val<value_bool>(val % 2 == 0);
+        }},
+        {"test_is_false", [](const func_args & args) -> value {
+            args.ensure_count(1);
+            bool val = is_val<value_bool>(args.get_pos(0)) && !args.get_pos(0)->as_bool();
+            return mk_val<value_bool>(val);
+        }},
+        {"test_is_true", [](const func_args & args) -> value {
+            args.ensure_count(1);
+            bool val = is_val<value_bool>(args.get_pos(0)) && args.get_pos(0)->as_bool();
+            return mk_val<value_bool>(val);
+        }},
+        {"test_is_divisibleby", [](const func_args & args) -> value {
+            args.ensure_vals<value_int, value_int>();
+            bool res = args.get_pos(0)->val_int % args.get_pos(1)->val_int == 0;
+            return mk_val<value_bool>(res);
+        }},
+        {"test_is_string", test_type_fn<value_string>},
+        {"test_is_integer", test_type_fn<value_int>},
+        {"test_is_float", test_type_fn<value_float>},
+        {"test_is_number", test_type_fn<value_int, value_float>},
+        {"test_is_iterable", test_type_fn<value_array, value_string, value_undefined>},
+        {"test_is_sequence", test_type_fn<value_array, value_string, value_undefined>},
+        {"test_is_mapping", test_type_fn<value_object>},
+        {"test_is_lower", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            return mk_val<value_bool>(args.get_pos(0)->val_str.is_lowercase());
+        }},
+        {"test_is_upper", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            return mk_val<value_bool>(args.get_pos(0)->val_str.is_uppercase());
+        }},
+        {"test_is_none", test_type_fn<value_none>},
+        {"test_is_defined", [](const func_args & args) -> value {
+            args.ensure_count(1);
+            bool res = !args.get_pos(0)->is_undefined();
+            JJ_DEBUG("test_is_defined: result=%d", res ? 1 : 0);
+            return mk_val<value_bool>(res);
+        }},
+        {"test_is_undefined", test_type_fn<value_undefined>},
+        {"test_is_eq", test_compare_fn<value_compare_op::eq>},
+        {"test_is_equalto", test_compare_fn<value_compare_op::eq>},
+        {"test_is_ge", test_compare_fn<value_compare_op::ge>},
+        {"test_is_gt", test_compare_fn<value_compare_op::gt>},
+        {"test_is_greaterthan", test_compare_fn<value_compare_op::gt>},
+        {"test_is_lt", test_compare_fn<value_compare_op::lt>},
+        {"test_is_lessthan", test_compare_fn<value_compare_op::lt>},
+        {"test_is_ne", test_compare_fn<value_compare_op::ne>},
+        {"test_is_in", [](const func_args & args) -> value {
+            args.ensure_count(2);
+            auto needle   = args.get_pos(0);
+            auto haystack = args.get_pos(1);
+            if (is_val<value_undefined>(haystack)) {
+                return mk_val<value_bool>(false);
+            }
+            if (is_val<value_array>(haystack)) {
+                for (const auto & item : haystack->as_array()) {
+                    if (*needle == *item) {
+                        return mk_val<value_bool>(true);
+                    }
+                }
+                return mk_val<value_bool>(false);
+            }
+            if (is_val<value_string>(haystack)) {
+                if (!is_val<value_string>(needle)) {
+                    throw raised_exception("'in' test expects args[1] as string when args[0] is string, got args[1] as " + needle->type());
+                }
+                return mk_val<value_bool>(
+                    haystack->as_string().str().find(needle->as_string().str()) != std::string::npos);
+            }
+            if (is_val<value_object>(haystack)) {
+                return mk_val<value_bool>(haystack->has_key(needle));
+            }
+            throw raised_exception("'in' test expects iterable as first argument, got " + haystack->type());
+        }},
+        {"test_is_test", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            auto & builtins = global_builtins();
+            std::string test_name = args.get_pos(0)->val_str.str();
+            auto it = builtins.find("test_is_" + test_name);
+            bool res = it != builtins.end();
+            return mk_val<value_bool>(res);
+        }},
+        {"test_is_sameas", [](const func_args & args) -> value {
+            // Check if an object points to the same memory address as another object
+            (void)args;
+            throw not_implemented_exception("sameas test not implemented");
+        }},
+        {"test_is_escaped", [](const func_args & args) -> value {
+            (void)args;
+            throw not_implemented_exception("escaped test not implemented");
+        }},
+        {"test_is_filter", [](const func_args & args) -> value {
+            (void)args;
+            throw not_implemented_exception("filter test not implemented");
+        }},
+    };
+    return builtins;
+}
+
+
+const func_builtins & value_int_t::get_builtins() const {
+    static const func_builtins builtins = {
+        {"default", default_value},
+        {"abs", [](const func_args & args) -> value {
+            args.ensure_vals<value_int>();
+            int64_t val = args.get_pos(0)->as_int();
+            return mk_val<value_int>(val < 0 ? -val : val);
+        }},
+        {"float", [](const func_args & args) -> value {
+            args.ensure_vals<value_int>();
+            double val = static_cast<double>(args.get_pos(0)->as_int());
+            return mk_val<value_float>(val);
+        }},
+        {"tojson", tojson},
+        {"string", tojson},
+    };
+    return builtins;
+}
+
+
+const func_builtins & value_float_t::get_builtins() const {
+    static const func_builtins builtins = {
+        {"default", default_value},
+        {"abs", [](const func_args & args) -> value {
+            args.ensure_vals<value_float>();
+            double val = args.get_pos(0)->as_float();
+            return mk_val<value_float>(val < 0.0 ? -val : val);
+        }},
+        {"int", [](const func_args & args) -> value {
+            args.ensure_vals<value_float>();
+            int64_t val = static_cast<int64_t>(args.get_pos(0)->as_float());
+            return mk_val<value_int>(val);
+        }},
+        {"tojson", tojson},
+        {"string", tojson},
+    };
+    return builtins;
+}
+
+static bool string_startswith(const std::string & str, const std::string & prefix) {
+    if (str.length() < prefix.length()) return false;
+    return str.compare(0, prefix.length(), prefix) == 0;
+}
+
+static bool string_endswith(const std::string & str, const std::string & suffix) {
+    if (str.length() < suffix.length()) return false;
+    return str.compare(str.length() - suffix.length(), suffix.length(), suffix) == 0;
+}
+
+const func_builtins & value_string_t::get_builtins() const {
+    static const func_builtins builtins = {
+        {"default", default_value},
+        {"upper", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            jinja::string str = args.get_pos(0)->as_string().uppercase();
+            return mk_val<value_string>(str);
+        }},
+        {"lower", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            jinja::string str = args.get_pos(0)->as_string().lowercase();
+            return mk_val<value_string>(str);
+        }},
+        {"strip", [](const func_args & args) -> value {
+            value val_input = args.get_pos(0);
+            if (!is_val<value_string>(val_input)) {
+                throw raised_exception("strip() first argument must be a string");
+            }
+            value val_chars = args.get_kwarg_or_pos("chars", 1);
+            if (val_chars->is_undefined()) {
+                return mk_val<value_string>(args.get_pos(0)->as_string().strip(true, true));
+            } else {
+                return mk_val<value_string>(args.get_pos(0)->as_string().strip(true, true, val_chars->as_string().str()));
+            }
+        }},
+        {"rstrip", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            value val_chars = args.get_kwarg_or_pos("chars", 1);
+            if (val_chars->is_undefined()) {
+                return mk_val<value_string>(args.get_pos(0)->as_string().strip(false, true));
+            } else {
+                return mk_val<value_string>(args.get_pos(0)->as_string().strip(false, true, val_chars->as_string().str()));
+            }
+        }},
+        {"lstrip", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            value val_chars = args.get_kwarg_or_pos("chars", 1);
+            if (val_chars->is_undefined()) {
+                return mk_val<value_string>(args.get_pos(0)->as_string().strip(true, false));
+            } else {
+                return mk_val<value_string>(args.get_pos(0)->as_string().strip(true, false, val_chars->as_string().str()));
+            }
+        }},
+        {"title", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            jinja::string str = args.get_pos(0)->as_string().titlecase();
+            return mk_val<value_string>(str);
+        }},
+        {"capitalize", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            jinja::string str = args.get_pos(0)->as_string().capitalize();
+            return mk_val<value_string>(str);
+        }},
+        {"length", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            jinja::string str = args.get_pos(0)->as_string();
+            return mk_val<value_int>(str.length());
+        }},
+        {"startswith", [](const func_args & args) -> value {
+            args.ensure_vals<value_string, value_string>();
+            std::string str = args.get_pos(0)->as_string().str();
+            std::string prefix = args.get_pos(1)->as_string().str();
+            return mk_val<value_bool>(string_startswith(str, prefix));
+        }},
+        {"endswith", [](const func_args & args) -> value {
+            args.ensure_vals<value_string, value_string>();
+            std::string str = args.get_pos(0)->as_string().str();
+            std::string suffix = args.get_pos(1)->as_string().str();
+            return mk_val<value_bool>(string_endswith(str, suffix));
+        }},
+        {"split", [](const func_args & args) -> value {
+            args.ensure_count(1, 3);
+            value val_input = args.get_pos(0);
+            if (!is_val<value_string>(val_input)) {
+                throw raised_exception("split() first argument must be a string");
+            }
+            std::string str = val_input->as_string().str();
+            // FIXME: Support non-specified delimiter (split on consecutive (no leading or trailing) whitespace)
+            std::string delim = (args.count() > 1) ? args.get_pos(1)->as_string().str() : " ";
+            int64_t maxsplit = (args.count() > 2) ? args.get_pos(2)->as_int() : -1;
+            auto result = mk_val<value_array>();
+            size_t pos = 0;
+            std::string token;
+            while ((pos = str.find(delim)) != std::string::npos && maxsplit != 0) {
+                token = str.substr(0, pos);
+                result->push_back(mk_val<value_string>(token));
+                str.erase(0, pos + delim.length());
+                --maxsplit;
+            }
+            auto res = mk_val<value_string>(str);
+            res->val_str.mark_input_based_on(args.get_pos(0)->val_str);
+            result->push_back(std::move(res));
+            return result;
+        }},
+        {"rsplit", [](const func_args & args) -> value {
+            args.ensure_count(1, 3);
+            value val_input = args.get_pos(0);
+            if (!is_val<value_string>(val_input)) {
+                throw raised_exception("rsplit() first argument must be a string");
+            }
+            std::string str = val_input->as_string().str();
+            // FIXME: Support non-specified delimiter (split on consecutive (no leading or trailing) whitespace)
+            std::string delim = (args.count() > 1) ? args.get_pos(1)->as_string().str() : " ";
+            int64_t maxsplit = (args.count() > 2) ? args.get_pos(2)->as_int() : -1;
+            auto result = mk_val<value_array>();
+            size_t pos = 0;
+            std::string token;
+            while ((pos = str.rfind(delim)) != std::string::npos && maxsplit != 0) {
+                token = str.substr(pos + delim.length());
+                result->push_back(mk_val<value_string>(token));
+                str.erase(pos);
+                --maxsplit;
+            }
+            auto res = mk_val<value_string>(str);
+            res->val_str.mark_input_based_on(args.get_pos(0)->val_str);
+            result->push_back(std::move(res));
+            result->reverse();
+            return result;
+        }},
+        {"replace", [](const func_args & args) -> value {
+            args.ensure_vals<value_string, value_string, value_string, value_int>(true, true, true, false);
+            std::string str = args.get_pos(0)->as_string().str();
+            std::string old_str = args.get_pos(1)->as_string().str();
+            std::string new_str = args.get_pos(2)->as_string().str();
+            int64_t count = args.count() > 3 ? args.get_pos(3)->as_int() : -1;
+            if (count > 0) {
+                throw not_implemented_exception("String replace with count argument not implemented");
+            }
+            size_t pos = 0;
+            while ((pos = str.find(old_str, pos)) != std::string::npos) {
+                str.replace(pos, old_str.length(), new_str);
+                pos += new_str.length();
+            }
+            auto res = mk_val<value_string>(str);
+            res->val_str.mark_input_based_on(args.get_pos(0)->val_str);
+            return res;
+        }},
+        {"int", [](const func_args & args) -> value {
+            value val_input   = args.get_pos(0);
+            value val_default = args.get_kwarg_or_pos("default", 1);
+            value val_base    = args.get_kwarg_or_pos("base",    2);
+            const int base = val_base->is_undefined() ? 10 : val_base->as_int();
+            if (is_val<value_string>(val_input) == false) {
+                throw raised_exception("int() first argument must be a string");
+            }
+            std::string str = val_input->as_string().str();
+            try {
+                return mk_val<value_int>(std::stoi(str, nullptr, base));
+            } catch (...) {
+                return mk_val<value_int>(val_default->is_undefined() ? 0 : val_default->as_int());
+            }
+        }},
+        {"float", [](const func_args & args) -> value {
+            args.ensure_vals<value_string>();
+            value val_default = args.get_kwarg_or_pos("default", 1);
+            std::string str = args.get_pos(0)->as_string().str();
+            try {
+                return mk_val<value_float>(std::stod(str));
+            } catch (...) {
+                return mk_val<value_float>(val_default->is_undefined() ? 0.0 : val_default->as_float());
+            }
+        }},
+        {"string", [](const func_args & args) -> value {
+            // no-op
+            args.ensure_vals<value_string>();
+            return mk_val<value_string>(args.get_pos(0)->as_string());
+        }},
+        {"default", [](const func_args & args) -> value {
+            value input = args.get_pos(0);
+            if (!is_val<value_string>(input)) {
+                throw raised_exception("default() first argument must be a string");
+            }
+            value default_val = mk_val<value_string>("");
+            if (args.count() > 1 && !args.get_pos(1)->is_undefined()) {
+                default_val = args.get_pos(1);
+            }
+            value boolean_val = args.get_kwarg_or_pos("boolean", 2); // undefined == false
+            if (input->is_undefined() || (boolean_val->as_bool() && !input->as_bool())) {
+                return default_val;
+            } else {
+                return input;
+            }
+        }},
+        {"slice", [](const func_args & args) -> value {
+            args.ensure_count(1, 4);
+            args.ensure_vals<value_string, value_int, value_int, value_int>(true, true, false, false);
+
+            auto arg0 = args.get_pos(1);
+            auto arg1 = args.get_pos(2, mk_val<value_undefined>());
+            auto arg2 = args.get_pos(3, mk_val<value_undefined>());
+
+            int64_t start, stop, step;
+            if (args.count() == 1) {
+                start = 0;
+                stop = arg0->as_int();
+                step = 1;
+            } else if (args.count() == 2) {
+                start = arg0->as_int();
+                stop = arg1->as_int();
+                step = 1;
+            } else {
+                start = arg0->as_int();
+                stop = arg1->as_int();
+                step = arg2->as_int();
+            }
+            if (step == 0) {
+                throw raised_exception("slice step cannot be zero");
+            }
+            auto input = args.get_pos(0);
+            auto sliced = slice(input->as_string().str(), start, stop, step);
+            auto res = mk_val<value_string>(sliced);
+            res->val_str.mark_input_based_on(input->as_string());
+            return res;
+        }},
+        {"safe", [](const func_args & args) -> value {
+            // no-op for now
+            args.ensure_vals<value_string>();
+            return args.get_pos(0);
+        }},
+        {"tojson", tojson},
+        {"indent", [](const func_args &) -> value {
+            throw not_implemented_exception("String indent builtin not implemented");
+        }},
+        {"join", [](const func_args &) -> value {
+            throw not_implemented_exception("String join builtin not implemented");
+        }},
+    };
+    return builtins;
+}
+
+
+const func_builtins & value_bool_t::get_builtins() const {
+    static const func_builtins builtins = {
+        {"default", default_value},
+        {"int", [](const func_args & args) -> value {
+            args.ensure_vals<value_bool>();
+            bool val = args.get_pos(0)->as_bool();
+            return mk_val<value_int>(val ? 1 : 0);
+        }},
+        {"float", [](const func_args & args) -> value {
+            args.ensure_vals<value_bool>();
+            bool val = args.get_pos(0)->as_bool();
+            return mk_val<value_float>(val ? 1.0 : 0.0);
+        }},
+        {"string", [](const func_args & args) -> value {
+            args.ensure_vals<value_bool>();
+            bool val = args.get_pos(0)->as_bool();
+            return mk_val<value_string>(val ? "True" : "False");
+        }},
+        {"tojson", tojson},
+    };
+    return builtins;
+}
+
+
+const func_builtins & value_array_t::get_builtins() const {
+    static const func_builtins builtins = {
+        {"default", default_value},
+        {"list", [](const func_args & args) -> value {
+            args.ensure_vals<value_array>();
+            const auto & arr = args.get_pos(0)->as_array();
+            auto result = mk_val<value_array>();
+            for (const auto& v : arr) {
+                result->push_back(v);
+            }
+            return result;
+        }},
+        {"first", [](const func_args & args) -> value {
+            args.ensure_vals<value_array>();
+            const auto & arr = args.get_pos(0)->as_array();
+            if (arr.empty()) {
+                return mk_val<value_undefined>();
+            }
+            return arr[0];
+        }},
+        {"last", [](const func_args & args) -> value {
+            args.ensure_vals<value_array>();
+            const auto & arr = args.get_pos(0)->as_array();
+            if (arr.empty()) {
+                return mk_val<value_undefined>();
+            }
+            return arr[arr.size() - 1];
+        }},
+        {"length", [](const func_args & args) -> value {
+            args.ensure_vals<value_array>();
+            const auto & arr = args.get_pos(0)->as_array();
+            return mk_val<value_int>(static_cast<int64_t>(arr.size()));
+        }},
+        {"slice", [](const func_args & args) -> value {
+            args.ensure_count(1, 4);
+            args.ensure_vals<value_array, value_int, value_int, value_int>(true, true, false, false);
+
+            auto val  = args.get_pos(0);
+            auto arg0 = args.get_pos(1);
+            auto arg1 = args.get_pos(2, mk_val<value_undefined>());
+            auto arg2 = args.get_pos(3, mk_val<value_undefined>());
+
+            int64_t start, stop, step;
+            if (args.count() == 1) {
+                start = 0;
+                stop = arg0->as_int();
+                step = 1;
+            } else if (args.count() == 2) {
+                start = arg0->as_int();
+                stop = arg1->as_int();
+                step = 1;
+            } else {
+                start = arg0->as_int();
+                stop = arg1->as_int();
+                step = arg2->as_int();
+            }
+            if (step == 0) {
+                throw raised_exception("slice step cannot be zero");
+            }
+            auto arr = slice(val->as_array(), start, stop, step);
+            return is_val<value_tuple>(val) ? mk_val<value_tuple>(std::move(arr)) : mk_val<value_array>(std::move(arr));
+        }},
+        {"selectattr", selectattr<false>},
+        {"select", selectattr<false>},
+        {"rejectattr", selectattr<true>},
+        {"reject", selectattr<true>},
+        {"join", [](const func_args & args) -> value {
+            args.ensure_count(1, 3);
+            if (!is_val<value_array>(args.get_pos(0))) {
+                throw raised_exception("join() first argument must be an array");
+            }
+            value val_delim = args.get_kwarg_or_pos("d",         1);
+            value attribute = args.get_kwarg_or_pos("attribute", 2);
+            const auto & arr = args.get_pos(0)->as_array();
+            const bool attr_is_int = is_val<value_int>(attribute);
+            if (!attribute->is_undefined() && !is_val<value_string>(attribute) && !attr_is_int) {
+                throw raised_exception("join() attribute must be string or integer");
+            }
+            const int64_t attr_int = attr_is_int ? attribute->as_int() : 0;
+            const std::string delim = val_delim->is_undefined() ? "" : val_delim->as_string().str();
+            std::string result;
+            for (size_t i = 0; i < arr.size(); ++i) {
+                value val_arr = arr[i];
+                if (!attribute->is_undefined()) {
+                    if (attr_is_int && is_val<value_array>(val_arr)) {
+                        val_arr = val_arr->at(attr_int);
+                    } else if (!attr_is_int && is_val<value_object>(val_arr)) {
+                        val_arr = val_arr->at(attribute);
+                    }
+                }
+                if (!is_val<value_string>(val_arr) && !is_val<value_int>(val_arr) && !is_val<value_float>(val_arr)) {
+                    throw raised_exception("join() can only join arrays of strings or numerics");
+                }
+                result += val_arr->as_string().str();
+                if (i < arr.size() - 1) {
+                    result += delim;
+                }
+            }
+            return mk_val<value_string>(result);
+        }},
+        {"string", [](const func_args & args) -> value {
+            args.ensure_vals<value_array>();
+            return mk_val<value_string>(args.get_pos(0)->as_string());
+        }},
+        {"tojson", tojson},
+        {"map", [](const func_args & args) -> value {
+            args.ensure_count(2);
+            if (!is_val<value_array>(args.get_pos(0))) {
+                throw raised_exception("map: first argument must be an array");
+            }
+            if (!is_val<value_kwarg>(args.get_args().at(1))) {
+                throw not_implemented_exception("map: filter-mapping not implemented");
+            }
+            value val       = args.get_pos(0);
+            value attribute = args.get_kwarg_or_pos("attribute", 1);
+            const bool attr_is_int = is_val<value_int>(attribute);
+            if (!is_val<value_string>(attribute) && !attr_is_int) {
+                throw raised_exception("map: attribute must be string or integer");
+            }
+            const int64_t attr_int = attr_is_int ? attribute->as_int() : 0;
+            value default_val = args.get_kwarg("default", mk_val<value_undefined>());
+            auto out = mk_val<value_array>();
+            auto arr = val->as_array();
+            for (const auto & item : arr) {
+                value attr_val;
+                if (attr_is_int) {
+                    attr_val = is_val<value_array>(item) ? item->at(attr_int, default_val) : default_val;
+                } else {
+                    attr_val = is_val<value_object>(item) ? item->at(attribute, default_val) : default_val;
+                }
+                out->push_back(attr_val);
+            }
+            return is_val<value_tuple>(val) ? mk_val<value_tuple>(std::move(out->as_array())) : out;
+        }},
+        {"append", [](const func_args & args) -> value {
+            args.ensure_count(2);
+            if (!is_val<value_array>(args.get_pos(0))) {
+                throw raised_exception("append: first argument must be an array");
+            }
+            const value_array_t * arr = cast_val<value_array>(args.get_pos(0));
+            // need to use const_cast here to modify the array
+            value_array_t * arr_editable = const_cast<value_array_t *>(arr);
+            arr_editable->push_back(args.get_pos(1));
+            return args.get_pos(0);
+        }},
+        {"pop", [](const func_args & args) -> value {
+            args.ensure_count(1, 2);
+            args.ensure_vals<value_array, value_int>(true, false);
+            int64_t index = args.count() == 2 ? args.get_pos(1)->as_int() : -1;
+            const value_array_t * arr = cast_val<value_array>(args.get_pos(0));
+            // need to use const_cast here to modify the array
+            value_array_t * arr_editable = const_cast<value_array_t *>(arr);
+            return arr_editable->pop_at(index);
+        }},
+        {"sort", [](const func_args & args) -> value {
+            args.ensure_count(1, 4);
+            if (!is_val<value_array>(args.get_pos(0))) {
+                throw raised_exception("sort: first argument must be an array");
+            }
+            value val         = args.get_pos(0);
+            value val_reverse = args.get_kwarg_or_pos("reverse",        1);
+            value val_case    = args.get_kwarg_or_pos("case_sensitive", 2);
+            value attribute   = args.get_kwarg_or_pos("attribute",      3);
+            // FIXME: sorting is currently always case sensitive
+            //const bool case_sensitive = val_case->as_bool(); // undefined == false
+            const bool reverse = val_reverse->as_bool(); // undefined == false
+            const bool attr_is_int = is_val<value_int>(attribute);
+            const int64_t attr_int = attr_is_int ? attribute->as_int() : 0;
+            std::vector<value> arr = val->as_array(); // copy
+            std::sort(arr.begin(), arr.end(),[&](const value & a, const value & b) {
+                value val_a = a;
+                value val_b = b;
+                if (!attribute->is_undefined()) {
+                    if (attr_is_int && is_val<value_array>(a) && is_val<value_array>(b)) {
+                        val_a = a->at(attr_int);
+                        val_b = b->at(attr_int);
+                    } else if (!attr_is_int && is_val<value_object>(a) && is_val<value_object>(b)) {
+                        val_a = a->at(attribute);
+                        val_b = b->at(attribute);
+                    } else {
+                        throw raised_exception("sort: unsupported object attribute comparison between " + a->type() + " and " + b->type());
+                    }
+                }
+                return value_compare(val_a, val_b, reverse ? value_compare_op::gt : value_compare_op::lt);
+            });
+            return is_val<value_tuple>(val) ? mk_val<value_tuple>(std::move(arr)) : mk_val<value_array>(std::move(arr));
+        }},
+        {"reverse", [](const func_args & args) -> value {
+            args.ensure_vals<value_array>();
+            value val = args.get_pos(0);
+            std::vector<value> arr = val->as_array(); // copy
+            std::reverse(arr.begin(), arr.end());
+            return is_val<value_tuple>(val) ? mk_val<value_tuple>(std::move(arr)) : mk_val<value_array>(std::move(arr));
+        }},
+        {"unique", [](const func_args &) -> value {
+            throw not_implemented_exception("Array unique builtin not implemented");
+        }},
+    };
+    return builtins;
+}
+
+
+const func_builtins & value_object_t::get_builtins() const {
+    if (!has_builtins) {
+        static const func_builtins no_builtins = {};
+        return no_builtins;
+    }
+
+    static const func_builtins builtins = {
+        // {"default", default_value}, // cause issue with gpt-oss
+        {"get", [](const func_args & args) -> value {
+            args.ensure_count(2, 3);
+            if (!is_val<value_object>(args.get_pos(0))) {
+                throw raised_exception("get: first argument must be an object");
+            }
+            if (!is_val<value_string>(args.get_pos(1))) {
+                throw raised_exception("get: second argument must be a string (key)");
+            }
+            value default_val = mk_val<value_none>();
+            if (args.count() == 3) {
+                default_val = args.get_pos(2);
+            }
+            const value obj = args.get_pos(0);
+            const value key = args.get_pos(1);
+            return obj->at(key, default_val);
+        }},
+        {"keys", [](const func_args & args) -> value {
+            args.ensure_vals<value_object>();
+            const auto & obj = args.get_pos(0)->as_ordered_object();
+            auto result = mk_val<value_array>();
+            for (const auto & pair : obj) {
+                result->push_back(pair.first);
+            }
+            return result;
+        }},
+        {"values", [](const func_args & args) -> value {
+            args.ensure_vals<value_object>();
+            const auto & obj = args.get_pos(0)->as_ordered_object();
+            auto result = mk_val<value_array>();
+            for (const auto & pair : obj) {
+                result->push_back(pair.second);
+            }
+            return result;
+        }},
+        {"items", [](const func_args & args) -> value {
+            args.ensure_vals<value_object>();
+            const auto & obj = args.get_pos(0)->as_ordered_object();
+            auto result = mk_val<value_array>();
+            for (const auto & pair : obj) {
+                auto item = mk_val<value_tuple>(pair);
+                result->push_back(std::move(item));
+            }
+            return result;
+        }},
+        {"tojson", tojson},
+        {"string", [](const func_args & args) -> value {
+            args.ensure_vals<value_object>();
+            return mk_val<value_string>(args.get_pos(0)->as_string());
+        }},
+        {"length", [](const func_args & args) -> value {
+            args.ensure_vals<value_object>();
+            const auto & obj = args.get_pos(0)->as_ordered_object();
+            return mk_val<value_int>(static_cast<int64_t>(obj.size()));
+        }},
+        {"tojson", [](const func_args & args) -> value {
+            args.ensure_vals<value_object>();
+            // use global to_json
+            return global_builtins().at("tojson")(args);
+        }},
+        {"dictsort", [](const func_args & args) -> value {
+            value val_input   = args.get_pos(0);
+            value val_case    = args.get_kwarg_or_pos("case_sensitive", 1);
+            value val_by      = args.get_kwarg_or_pos("by",             2);
+            value val_reverse = args.get_kwarg_or_pos("reverse",        3);
+            // FIXME: sorting is currently always case sensitive
+            //const bool case_sensitive = val_case->as_bool(); // undefined == false
+            const bool reverse = val_reverse->as_bool(); // undefined == false
+            const bool by_value = is_val<value_string>(val_by) && val_by->as_string().str() == "value" ? true : false;
+            auto result = mk_val<value_object>(val_input); // copy
+            std::sort(result->val_obj.begin(), result->val_obj.end(), [&](const auto & a, const auto & b) {
+                if (by_value) {
+                    return value_compare(a.second, b.second, reverse ? value_compare_op::gt : value_compare_op::lt);
+                } else {
+                    return value_compare(a.first, b.first, reverse ? value_compare_op::gt : value_compare_op::lt);
+                }
+            });
+            return result;
+        }},
+        {"join", [](const func_args &) -> value {
+            throw not_implemented_exception("object join not implemented");
+        }},
+    };
+    return builtins;
+}
+
+const func_builtins & value_none_t::get_builtins() const {
+    static const func_builtins builtins = {
+        {"default", default_value},
+        {"tojson", tojson},
+        {"string", [](const func_args &) -> value {
+            return mk_val<value_string>("None");
+        }},
+        {"safe", [](const func_args &) -> value {
+            return mk_val<value_string>("None");
+        }},
+        {"strip", [](const func_args &) -> value {
+            return mk_val<value_string>("None");
+        }},
+        {"items", empty_value_fn<value_array>},
+        {"map", empty_value_fn<value_array>},
+        {"reject", empty_value_fn<value_array>},
+        {"rejectattr", empty_value_fn<value_array>},
+        {"select", empty_value_fn<value_array>},
+        {"selectattr", empty_value_fn<value_array>},
+        {"unique", empty_value_fn<value_array>},
+    };
+    return builtins;
+}
+
+
+const func_builtins & value_undefined_t::get_builtins() const {
+    static const func_builtins builtins = {
+        {"default", default_value},
+        {"capitalize", empty_value_fn<value_string>},
+        {"first", empty_value_fn<value_undefined>},
+        {"items", empty_value_fn<value_array>},
+        {"join", empty_value_fn<value_string>},
+        {"last", empty_value_fn<value_undefined>},
+        {"length", empty_value_fn<value_int>},
+        {"list", empty_value_fn<value_array>},
+        {"lower", empty_value_fn<value_string>},
+        {"map", empty_value_fn<value_array>},
+        {"max", empty_value_fn<value_undefined>},
+        {"min", empty_value_fn<value_undefined>},
+        {"reject", empty_value_fn<value_array>},
+        {"rejectattr", empty_value_fn<value_array>},
+        {"replace", empty_value_fn<value_string>},
+        {"reverse", empty_value_fn<value_array>},
+        {"safe", empty_value_fn<value_string>},
+        {"select", empty_value_fn<value_array>},
+        {"selectattr", empty_value_fn<value_array>},
+        {"sort", empty_value_fn<value_array>},
+        {"string", empty_value_fn<value_string>},
+        {"strip", empty_value_fn<value_string>},
+        {"sum", empty_value_fn<value_int>},
+        {"title", empty_value_fn<value_string>},
+        {"truncate", empty_value_fn<value_string>},
+        {"unique", empty_value_fn<value_array>},
+        {"upper", empty_value_fn<value_string>},
+        {"wordcount", empty_value_fn<value_int>},
+    };
+    return builtins;
+}
+
+
+//////////////////////////////////
+
+
+static value from_json(const nlohmann::ordered_json & j, bool mark_input) {
+    if (j.is_null()) {
+        return mk_val<value_none>();
+    } else if (j.is_boolean()) {
+        return mk_val<value_bool>(j.get<bool>());
+    } else if (j.is_number_integer()) {
+        return mk_val<value_int>(j.get<int64_t>());
+    } else if (j.is_number_float()) {
+        return mk_val<value_float>(j.get<double>());
+    } else if (j.is_string()) {
+        auto str = mk_val<value_string>(j.get<std::string>());
+        if (mark_input) {
+            str->mark_input();
+        }
+        return str;
+    } else if (j.is_array()) {
+        auto arr = mk_val<value_array>();
+        for (const auto & item : j) {
+            arr->push_back(from_json(item, mark_input));
+        }
+        return arr;
+    } else if (j.is_object()) {
+        auto obj = mk_val<value_object>();
+        for (auto it = j.begin(); it != j.end(); ++it) {
+            obj->insert(it.key(), from_json(it.value(), mark_input));
+        }
+        return obj;
+    } else {
+        throw std::runtime_error("Unsupported JSON value type");
+    }
+}
+
+// compare operator for value_t
+bool value_compare(const value & a, const value & b, value_compare_op op) {
+    auto cmp = [&]() {
+        // compare numeric types
+        if ((is_val<value_int>(a) || is_val<value_float>(a)) &&
+            (is_val<value_int>(b) || is_val<value_float>(b))){
+            try {
+                if (op == value_compare_op::eq) {
+                    return a->as_float() == b->as_float();
+                } else if (op == value_compare_op::ge) {
+                    return a->as_float() >= b->as_float();
+                } else if (op == value_compare_op::gt) {
+                    return a->as_float() > b->as_float();
+                } else if (op == value_compare_op::lt) {
+                    return a->as_float() < b->as_float();
+                } else if (op == value_compare_op::ne) {
+                    return a->as_float() != b->as_float();
+                } else {
+                    throw std::runtime_error("Unsupported comparison operator for numeric types");
+                }
+            } catch (...) {}
+        }
+        // compare string and number
+        // TODO: not sure if this is the right behavior
+        if ((is_val<value_string>(b) && (is_val<value_int>(a) || is_val<value_float>(a))) ||
+            (is_val<value_string>(a) && (is_val<value_int>(b) || is_val<value_float>(b))) ||
+            (is_val<value_string>(a) && is_val<value_string>(b))) {
+            try {
+                if (op == value_compare_op::eq) {
+                    return a->as_string().str() == b->as_string().str();
+                } else if (op == value_compare_op::ge) {
+                    return a->as_string().str() >= b->as_string().str();
+                } else if (op == value_compare_op::gt) {
+                    return a->as_string().str() > b->as_string().str();
+                } else if (op == value_compare_op::lt) {
+                    return a->as_string().str() < b->as_string().str();
+                } else if (op == value_compare_op::ne) {
+                    return a->as_string().str() != b->as_string().str();
+                } else {
+                    throw std::runtime_error("Unsupported comparison operator for string/number types");
+                }
+            } catch (...) {}
+        }
+        // compare boolean simple
+        if (is_val<value_bool>(a) && is_val<value_bool>(b)) {
+            if (op == value_compare_op::eq) {
+                return a->as_bool() == b->as_bool();
+            } else if (op == value_compare_op::ne) {
+                return a->as_bool() != b->as_bool();
+            } else {
+                throw std::runtime_error("Unsupported comparison operator for bool type");
+            }
+        }
+        // compare by type
+        if (a->type() != b->type()) {
+            return false;
+        }
+        return false;
+    };
+    auto result = cmp();
+    JJ_DEBUG("Comparing types: %s and %s result=%d", a->type().c_str(), b->type().c_str(), result);
+    return result;
+}
+
+template<>
+void global_from_json(context & ctx, const nlohmann::ordered_json & json_obj, bool mark_input) {
+    // printf("global_from_json: %s\n" , json_obj.dump(2).c_str());
+    if (json_obj.is_null() || !json_obj.is_object()) {
+        throw std::runtime_error("global_from_json: input JSON value must be an object");
+    }
+    for (auto it = json_obj.begin(); it != json_obj.end(); ++it) {
+        JJ_DEBUG("global_from_json: setting key '%s'", it.key().c_str());
+        ctx.set_val(it.key(), from_json(it.value(), mark_input));
+    }
+}
+
+// recursively convert value to JSON string
+// TODO: avoid circular references
+static void value_to_json_internal(std::ostringstream & oss, const value & val, int curr_lvl, int indent, const std::string_view item_sep, const std::string_view key_sep) {
+    auto indent_str = [indent, curr_lvl]() -> std::string {
+        return (indent > 0) ? std::string(curr_lvl * indent, ' ') : "";
+    };
+    auto newline = [indent]() -> std::string {
+        return (indent >= 0) ? "\n" : "";
+    };
+
+    if (is_val<value_none>(val) || val->is_undefined()) {
+        oss << "null";
+    } else if (is_val<value_bool>(val)) {
+        oss << (val->as_bool() ? "true" : "false");
+    } else if (is_val<value_int>(val)) {
+        oss << val->as_int();
+    } else if (is_val<value_float>(val)) {
+        oss << val->as_float();
+    } else if (is_val<value_string>(val)) {
+        oss << "\"";
+        for (char c : val->as_string().str()) {
+            switch (c) {
+                case '"': oss << "\\\""; break;
+                case '\\': oss << "\\\\"; break;
+                case '\b': oss << "\\b"; break;
+                case '\f': oss << "\\f"; break;
+                case '\n': oss << "\\n"; break;
+                case '\r': oss << "\\r"; break;
+                case '\t': oss << "\\t"; break;
+                default:
+                    if (static_cast<unsigned char>(c) < 0x20) {
+                        char buf[7];
+                        snprintf(buf, sizeof(buf), "\\u%04x", static_cast<unsigned char>(c));
+                        oss << buf;
+                    } else {
+                        oss << c;
+                    }
+            }
+        }
+        oss << "\"";
+    } else if (is_val<value_array>(val)) {
+        const auto & arr = val->as_array();
+        oss << "[";
+        if (!arr.empty()) {
+            oss << newline();
+            for (size_t i = 0; i < arr.size(); ++i) {
+                oss << indent_str() << (indent > 0 ? std::string(indent, ' ') : "");
+                value_to_json_internal(oss, arr[i], curr_lvl + 1, indent, item_sep, key_sep);
+                if (i < arr.size() - 1) {
+                    oss << item_sep;
+                }
+                oss << newline();
+            }
+            oss << indent_str();
+        }
+        oss << "]";
+    } else if (is_val<value_object>(val)) {
+        const auto & obj = val->as_ordered_object(); // IMPORTANT: need to keep exact order
+        oss << "{";
+        if (!obj.empty()) {
+            oss << newline();
+            size_t i = 0;
+            for (const auto & pair : obj) {
+                oss << indent_str() << (indent > 0 ? std::string(indent, ' ') : "");
+                value_to_json_internal(oss, mk_val<value_string>(pair.first->as_string().str()), curr_lvl + 1, indent, item_sep, key_sep);
+                oss << key_sep;
+                value_to_json_internal(oss, pair.second, curr_lvl + 1, indent, item_sep, key_sep);
+                if (i < obj.size() - 1) {
+                    oss << item_sep;
+                }
+                oss << newline();
+                ++i;
+            }
+            oss << indent_str();
+        }
+        oss << "}";
+    } else {
+        oss << "null";
+    }
+}
+
+std::string value_to_json(const value & val, int indent, const std::string_view item_sep, const std::string_view key_sep) {
+    std::ostringstream oss;
+    value_to_json_internal(oss, val, 0, indent, item_sep, key_sep);
+    JJ_DEBUG("value_to_json: result=%s", oss.str().c_str());
+    return oss.str();
+}
+
+// TODO: avoid circular references
+std::string value_to_string_repr(const value & val) {
+    if (is_val<value_string>(val)) {
+        const std::string val_str = val->as_string().str();
+
+        if (val_str.find('\'') != std::string::npos) {
+            return value_to_json(val);
+        } else {
+            return "'" + val_str + "'";
+        }
+    } else {
+        return val->as_repr();
+    }
+}
+
+} // namespace jinja