pocketpy/src/pocketpy.cpp

#include "pocketpy/pocketpy.h"

namespace pkpy{

#ifdef PK_USE_CJSON
void add_module_cjson(VM* vm);
#endif

template<typename T>
PyObject* PyArrayGetItem(VM* vm, PyObject* _0, PyObject* _1){
    static_assert(std::is_same_v<T, List> || std::is_same_v<T, Tuple>);
    const T& self = _CAST(T&, _0);
    i64 index;
    if(try_cast_int(_1, &index)){
        index = vm->normalized_index(index, self.size());
        return self[index];
    }
    if(is_non_tagged_type(_1, vm->tp_slice)){
        const Slice& s = _CAST(Slice&, _1);
        int start, stop, step;
        vm->parse_int_slice(s, self.size(), start, stop, step);
        List new_list;
        PK_SLICE_LOOP(i, start, stop, step) new_list.push_back(self[i]);
        return VAR(T(std::move(new_list)));
    }
    vm->TypeError("indices must be integers or slices");
    PK_UNREACHABLE()
}

void init_builtins(VM* _vm) {
#define BIND_NUM_ARITH_OPT(name, op)                                                                    \
    _vm->bind##name(VM::tp_int, [](VM* vm, PyObject* lhs, PyObject* rhs) {                              \
        if(is_int(rhs)) return VAR(_CAST(i64, lhs) op _CAST(i64, rhs));                                 \
        if(is_float(rhs)) return VAR(_CAST(i64, lhs) op _CAST(f64, rhs));                               \
        return vm->NotImplemented;                                                                      \
    });                                                                                                 \
    _vm->bind##name(VM::tp_float, [](VM* vm, PyObject* lhs, PyObject* rhs) {                           \
        if(is_float(rhs)) return VAR(_CAST(f64, lhs) op _CAST(f64, rhs));                               \
        if(is_int(rhs)) return VAR(_CAST(f64, lhs) op _CAST(i64, rhs));                                 \
        return vm->NotImplemented;                                                                      \
    });

    BIND_NUM_ARITH_OPT(__add__, +)
    BIND_NUM_ARITH_OPT(__sub__, -)
    BIND_NUM_ARITH_OPT(__mul__, *)

#undef BIND_NUM_ARITH_OPT

#define BIND_NUM_LOGICAL_OPT(name, op)   \
    _vm->bind##name(VM::tp_int, [](VM* vm, PyObject* lhs, PyObject* rhs) {      \
        i64 val;                                                                \
        if(try_cast_int(rhs, &val)) return VAR(_CAST(i64, lhs) op val);         \
        if(is_float(rhs))   return VAR(_CAST(i64, lhs) op _CAST(f64, rhs));     \
        return vm->NotImplemented;                                              \
    });                                                                         \
    _vm->bind##name(VM::tp_float, [](VM* vm, PyObject* lhs, PyObject* rhs) {    \
        i64 val;                                                                \
        if(try_cast_int(rhs, &val)) return VAR(_CAST(f64, lhs) op val);         \
        if(is_float(rhs))   return VAR(_CAST(f64, lhs) op _CAST(f64, rhs));     \
        return vm->NotImplemented;                                              \
    });

    BIND_NUM_LOGICAL_OPT(__eq__, ==)
    BIND_NUM_LOGICAL_OPT(__lt__, <)
    BIND_NUM_LOGICAL_OPT(__le__, <=)
    BIND_NUM_LOGICAL_OPT(__gt__, >)
    BIND_NUM_LOGICAL_OPT(__ge__, >=)
    
#undef BIND_NUM_ARITH_OPT
#undef BIND_NUM_LOGICAL_OPT

    // builtin functions
    _vm->bind_func<-1>(_vm->builtins, "super", [](VM* vm, ArgsView args) {
        PyObject* class_arg = nullptr;
        PyObject* self_arg = nullptr;
        if(args.size() == 2){
            class_arg = args[0];
            self_arg = args[1];
        }else if(args.size() == 0){
            FrameId frame = vm->top_frame();
            if(frame->_callable != nullptr){
                class_arg = PK_OBJ_GET(Function, frame->_callable)._class;
                if(frame->_locals.size() > 0) self_arg = frame->_locals[0];
            }
            if(class_arg == nullptr || self_arg == nullptr){
                vm->TypeError("super(): unable to determine the class context, use super(class, self) instead");
            }
        }else{
            vm->TypeError("super() takes 0 or 2 arguments");
        }
        vm->check_non_tagged_type(class_arg, vm->tp_type);
        Type type = PK_OBJ_GET(Type, class_arg);
        if(!vm->isinstance(self_arg, type)){
            StrName _0 = _type_name(vm, vm->_tp(self_arg));
            StrName _1 = _type_name(vm, type);
            vm->TypeError("super(): " + _0.escape() + " is not an instance of " + _1.escape());
        }
        return vm->heap.gcnew<Super>(vm->tp_super, self_arg, vm->_all_types[type].base);
    });

    _vm->bind_func<1>(_vm->builtins, "staticmethod", [](VM* vm, ArgsView args) {
        PyObject* func = args[0];
        vm->check_non_tagged_type(func, vm->tp_function);
        return vm->heap.gcnew<StaticMethod>(vm->tp_staticmethod, args[0]);
    });

    _vm->bind_func<1>(_vm->builtins, "classmethod", [](VM* vm, ArgsView args) {
        PyObject* func = args[0];
        vm->check_non_tagged_type(func, vm->tp_function);
        return vm->heap.gcnew<ClassMethod>(vm->tp_classmethod, args[0]);
    });

    _vm->bind_func<2>(_vm->builtins, "isinstance", [](VM* vm, ArgsView args) {
        if(is_non_tagged_type(args[1], vm->tp_tuple)){
            Tuple& types = _CAST(Tuple&, args[1]);
            for(PyObject* type : types){
                vm->check_non_tagged_type(type, vm->tp_type);
                if(vm->isinstance(args[0], PK_OBJ_GET(Type, type))) return vm->True;
            }
            return vm->False;
        }
        vm->check_non_tagged_type(args[1], vm->tp_type);
        Type type = PK_OBJ_GET(Type, args[1]);
        return VAR(vm->isinstance(args[0], type));
    });

    _vm->bind_func<2>(_vm->builtins, "issubclass", [](VM* vm, ArgsView args) {
        vm->check_non_tagged_type(args[0], vm->tp_type);
        vm->check_non_tagged_type(args[1], vm->tp_type);
        return VAR(vm->issubclass(PK_OBJ_GET(Type, args[0]), PK_OBJ_GET(Type, args[1])));
    });

    _vm->bind_func<0>(_vm->builtins, "globals", [](VM* vm, ArgsView args) {
        PyObject* mod = vm->top_frame()->_module;
        return VAR(MappingProxy(mod));
    });

    _vm->bind(_vm->builtins, "round(x, ndigits=None)", [](VM* vm, ArgsView args) {
        if(is_int(args[0])) return args[0];
        f64 x = CAST(f64, args[0]);
        f64 offset = x >= 0 ? 0.5 : -0.5;
        if(args[1] == vm->None) return VAR((i64)(x + offset));
        int ndigits = CAST(int, args[1]);
        if(ndigits < 0) vm->ValueError("ndigits should be non-negative");
        // ndigits > 0
        return VAR((i64)(x * std::pow(10, ndigits) + offset) / std::pow(10, ndigits));
    });

    _vm->bind_func<1>(_vm->builtins, "abs", [](VM* vm, ArgsView args) {
        if(is_int(args[0])) return VAR(std::abs(_CAST(i64, args[0])));
        if(is_float(args[0])) return VAR(std::abs(_CAST(f64, args[0])));
        vm->TypeError("bad operand type for abs()");
        return vm->None;
    });

    _vm->bind_func<1>(_vm->builtins, "id", [](VM* vm, ArgsView args) {
        PyObject* obj = args[0];
        if(is_tagged(obj)) return vm->None;
        return VAR(PK_BITS(obj));
    });

    _vm->bind_func<1>(_vm->builtins, "callable", [](VM* vm, ArgsView args) {
        return VAR(vm->py_callable(args[0]));
    });

    _vm->bind_func<1>(_vm->builtins, "__import__", [](VM* vm, ArgsView args) {
        const Str& name = CAST(Str&, args[0]);
        return vm->py_import(name);
    });

    _vm->bind_func<2>(_vm->builtins, "divmod", [](VM* vm, ArgsView args) {
        if(is_int(args[0])){
            i64 lhs = _CAST(i64, args[0]);
            i64 rhs = CAST(i64, args[1]);
            if(rhs == 0) vm->ZeroDivisionError();
            auto res = std::div(lhs, rhs);
            return VAR(Tuple(VAR(res.quot), VAR(res.rem)));
        }else{
            return vm->call_method(args[0], __divmod__, args[1]);
        }
    });

    _vm->bind(_vm->builtins, "eval(__source, __globals=None)", [](VM* vm, ArgsView args) {
        CodeObject_ code = vm->compile(CAST(Str&, args[0]), "<eval>", EVAL_MODE, true);
        PyObject* globals = args[1];
        if(globals == vm->None){
            FrameId frame = vm->top_frame();
            return vm->_exec(code.get(), frame->_module, frame->_callable, frame->_locals);
        }
        vm->check_non_tagged_type(globals, vm->tp_mappingproxy);
        PyObject* obj = PK_OBJ_GET(MappingProxy, globals).obj;
        return vm->_exec(code, obj);
    });

    _vm->bind(_vm->builtins, "exec(__source, __globals=None)", [](VM* vm, ArgsView args) {
        CodeObject_ code = vm->compile(CAST(Str&, args[0]), "<exec>", EXEC_MODE, true);
        PyObject* globals = args[1];
        if(globals == vm->None){
            FrameId frame = vm->top_frame();
            vm->_exec(code.get(), frame->_module, frame->_callable, frame->_locals);
            return vm->None;
        }
        vm->check_non_tagged_type(globals, vm->tp_mappingproxy);
        PyObject* obj = PK_OBJ_GET(MappingProxy, globals).obj;
        vm->_exec(code, obj);
        return vm->None;
    });

    _vm->bind(_vm->builtins, "exit(code=0)", [](VM* vm, ArgsView args) {
        std::exit(CAST(int, args[0]));
        return vm->None;
    });

    _vm->bind_func<1>(_vm->builtins, "repr", [](VM* vm, ArgsView args){
        return vm->py_repr(args[0]);
    });

    _vm->bind_func<1>(_vm->builtins, "len", [](VM* vm, ArgsView args){
        const PyTypeInfo* ti = vm->_inst_type_info(args[0]);
        if(ti->m__len__) return VAR(ti->m__len__(vm, args[0]));
        return vm->call_method(args[0], __len__);
    });

    _vm->bind_func<1>(_vm->builtins, "hash", [](VM* vm, ArgsView args){
        i64 value = vm->py_hash(args[0]);
        return VAR(value);
    });

    _vm->bind_func<1>(_vm->builtins, "chr", [](VM* vm, ArgsView args) {
        i64 i = CAST(i64, args[0]);
        if (i < 0 || i >= 128) vm->ValueError("chr() arg not in [0, 128)");
        return VAR(std::string(1, (char)i));
    });

    _vm->bind_func<1>(_vm->builtins, "ord", [](VM* vm, ArgsView args) {
        const Str& s = CAST(Str&, args[0]);
        if (s.length()!=1) vm->TypeError("ord() expected an ASCII character");
        return VAR((i64)(s[0]));
    });

    _vm->bind_func<2>(_vm->builtins, "hasattr", [](VM* vm, ArgsView args) {
        return VAR(vm->getattr(args[0], CAST(Str&, args[1]), false) != nullptr);
    });

    _vm->bind_func<3>(_vm->builtins, "setattr", [](VM* vm, ArgsView args) {
        vm->setattr(args[0], CAST(Str&, args[1]), args[2]);
        return vm->None;
    });

    _vm->bind_func<-1>(_vm->builtins, "getattr", [](VM* vm, ArgsView args) {
        if(args.size()!=2 && args.size()!=3) vm->TypeError("getattr() takes 2 or 3 arguments");
        StrName name = CAST(Str&, args[1]);
        PyObject* val = vm->getattr(args[0], name, false);
        if(val == nullptr){
            if(args.size()==2) vm->AttributeError(args[0], name);
            return args[2];
        }
        return val;
    });

    _vm->bind_func<2>(_vm->builtins, "delattr", [](VM* vm, ArgsView args) {
        vm->delattr(args[0], CAST(Str&, args[1]));
        return vm->None;
    });

    _vm->bind_func<1>(_vm->builtins, "hex", [](VM* vm, ArgsView args) {
        SStream ss;
        ss.write_hex(CAST(i64, args[0]));
        return VAR(ss.str());
    });

    _vm->bind_func<1>(_vm->builtins, "iter", [](VM* vm, ArgsView args) {
        return vm->py_iter(args[0]);
    });

    _vm->bind_func<1>(_vm->builtins, "next", [](VM* vm, ArgsView args) {
        return vm->py_next(args[0]);
    });

    _vm->bind_func<1>(_vm->builtins, "bin", [](VM* vm, ArgsView args) {
        SStream ss;
        i64 x = CAST(i64, args[0]);
        if(x < 0){ ss << "-"; x = -x; }
        ss << "0b";
        std::string bits;
        while(x){
            bits += (x & 1) ? '1' : '0';
            x >>= 1;
        }
        std::reverse(bits.begin(), bits.end());
        if(bits.empty()) bits = "0";
        ss << bits;
        return VAR(ss.str());
    });

    _vm->bind_func<1>(_vm->builtins, "dir", [](VM* vm, ArgsView args) {
        std::set<StrName> names;
        if(!is_tagged(args[0]) && args[0]->is_attr_valid()){
            auto keys = args[0]->attr().keys();
            names.insert(keys.begin(), keys.end());
        }
        const NameDict& t_attr = vm->_t(args[0])->attr();
        auto keys = t_attr.keys();
        names.insert(keys.begin(), keys.end());
        List ret;
        for (StrName name : names) ret.push_back(VAR(name.sv()));
        return VAR(std::move(ret));
    });

    // tp_object
    _vm->bind__repr__(VM::tp_object, [](VM* vm, PyObject* obj) {
        if(is_tagged(obj)) PK_FATAL_ERROR();
        SStream ss;
        ss << "<" << _type_name(vm, vm->_tp(obj)) << " object at ";
        ss.write_hex(obj);
        ss << ">";
        return VAR(ss.str());
    });

    _vm->bind__eq__(VM::tp_object, [](VM* vm, PyObject* _0, PyObject* _1) {
        return VAR(_0 == _1); 
    });

    _vm->cached_object__new__ = _vm->bind_constructor<1>(_vm->_t(VM::tp_object), [](VM* vm, ArgsView args) {
        vm->check_non_tagged_type(args[0], vm->tp_type);
        Type t = PK_OBJ_GET(Type, args[0]);
        return vm->heap.gcnew<DummyInstance>(t);
    });

    _vm->bind_method<0>(VM::tp_object, "_enable_instance_dict", [](VM* vm, ArgsView args){
        PyObject* self = args[0];
        if(is_tagged(self)){
            vm->TypeError("object: tagged object cannot enable instance dict");
        }
        if(self->is_attr_valid()){
            vm->TypeError("object: instance dict is already enabled");
        }
        self->_enable_instance_dict();
        return vm->None;
    });

    // tp_type
    _vm->bind_constructor<2>(_vm->_t(VM::tp_type), PK_LAMBDA(vm->_t(args[1])));

    // tp_range
    _vm->bind_constructor<-1>(_vm->_t(VM::tp_range), [](VM* vm, ArgsView args) {
        args._begin += 1;   // skip cls
        Range r;
        switch (args.size()) {
            case 1: r.stop = CAST(i64, args[0]); break;
            case 2: r.start = CAST(i64, args[0]); r.stop = CAST(i64, args[1]); break;
            case 3: r.start = CAST(i64, args[0]); r.stop = CAST(i64, args[1]); r.step = CAST(i64, args[2]); break;
            default: vm->TypeError("expected 1-3 arguments, got " + std::to_string(args.size()));
        }
        return VAR(r);
    });

    _vm->bind__iter__(VM::tp_range, [](VM* vm, PyObject* obj) { return VAR_T(RangeIter, PK_OBJ_GET(Range, obj)); });
    
    // tp_nonetype
    _vm->bind__repr__(_vm->_tp(_vm->None), [](VM* vm, PyObject* _0) {
        return VAR("None"); 
    });

    // tp_float / tp_float
    _vm->bind__truediv__(VM::tp_float, [](VM* vm, PyObject* _0, PyObject* _1) {
        f64 value = CAST_F(_1);
        return VAR(_CAST(f64, _0) / value);
    });
    _vm->bind__truediv__(VM::tp_int, [](VM* vm, PyObject* _0, PyObject* _1) {
        f64 value = CAST_F(_1);
        return VAR(_CAST(i64, _0) / value);
    });

    auto py_number_pow = [](VM* vm, PyObject* _0, PyObject* _1) {
        i64 lhs, rhs;
        if(try_cast_int(_0, &lhs) && try_cast_int(_1, &rhs)){
            if(rhs < 0) {
                if(lhs == 0) vm->ZeroDivisionError("0.0 cannot be raised to a negative power");
                return VAR((f64)std::pow(lhs, rhs));
            }
            i64 ret = 1;
            while(rhs){
                if(rhs & 1) ret *= lhs;
                lhs *= lhs;
                rhs >>= 1;
            }
            return VAR(ret);
        }else{
            return VAR((f64)std::pow(CAST_F(_0), CAST_F(_1)));
        }
    };

    _vm->bind__pow__(VM::tp_int, py_number_pow);
    _vm->bind__pow__(VM::tp_float, py_number_pow);

    _vm->bind_constructor<-1>(_vm->_t(VM::tp_int), [](VM* vm, ArgsView args) {
        if(args.size() == 1+0) return VAR(0);
        // 1 arg
        if(args.size() == 1+1){
            if (is_type(args[1], vm->tp_float)) return VAR((i64)CAST(f64, args[1]));
            if (is_type(args[1], vm->tp_int)) return args[1];
            if (is_type(args[1], vm->tp_bool)) return VAR(_CAST(bool, args[1]) ? 1 : 0);
        }
        if(args.size() > 1+2) vm->TypeError("int() takes at most 2 arguments");
        // 2 args
        if (is_type(args[1], vm->tp_str)) {
            int base = 10;
            if(args.size() == 1+2) base = CAST(i64, args[2]);
            const Str& s = CAST(Str&, args[1]);
            std::string_view sv = s.sv();
            bool negative = false;
            if(!sv.empty() && (sv[0] == '+' || sv[0] == '-')){
                negative = sv[0] == '-';
                sv.remove_prefix(1);
            }
            i64 val;
            if(parse_int(sv, &val, base) != IntParsingResult::Success){
                vm->ValueError(_S("invalid literal for int() with base ", base, ": ", s.escape()));
            }
            if(negative) val = -val;
            return VAR(val);
        }
        vm->TypeError("invalid arguments for int()");
        return vm->None;
    });

    _vm->bind__floordiv__(VM::tp_int, [](VM* vm, PyObject* _0, PyObject* _1) {
        i64 rhs = CAST(i64, _1);
        if(rhs == 0) vm->ZeroDivisionError();
        return VAR(_CAST(i64, _0) / rhs);
    });

    _vm->bind__mod__(VM::tp_int, [](VM* vm, PyObject* _0, PyObject* _1) {
        i64 rhs = CAST(i64, _1);
        if(rhs == 0) vm->ZeroDivisionError();
        return VAR(_CAST(i64, _0) % rhs);
    });

    _vm->bind__repr__(VM::tp_int, [](VM* vm, PyObject* obj) { return VAR(std::to_string(_CAST(i64, obj))); });
    _vm->bind__neg__(VM::tp_int, [](VM* vm, PyObject* obj) { return VAR(-_CAST(i64, obj)); });
    _vm->bind__hash__(VM::tp_int, [](VM* vm, PyObject* obj) { return _CAST(i64, obj); });
    _vm->bind__invert__(VM::tp_int, [](VM* vm, PyObject* obj) { return VAR(~_CAST(i64, obj)); });

#define INT_BITWISE_OP(name, op) \
    _vm->bind##name(VM::tp_int, [](VM* vm, PyObject* lhs, PyObject* rhs) { \
        return VAR(_CAST(i64, lhs) op CAST(i64, rhs)); \
    });

    INT_BITWISE_OP(__lshift__, <<)
    INT_BITWISE_OP(__rshift__, >>)
    INT_BITWISE_OP(__and__, &)
    INT_BITWISE_OP(__or__, |)
    INT_BITWISE_OP(__xor__, ^)

#undef INT_BITWISE_OP

    _vm->bind_constructor<-1>(_vm->_t(VM::tp_float), [](VM* vm, ArgsView args) {
        if(args.size() == 1+0) return VAR(0.0);
        if(args.size() > 1+1) vm->TypeError("float() takes at most 1 argument");
        // 1 arg
        if (is_type(args[1], vm->tp_int)) return VAR((f64)CAST(i64, args[1]));
        if (is_type(args[1], vm->tp_float)) return args[1];
        if (is_type(args[1], vm->tp_bool)) return VAR(_CAST(bool, args[1]) ? 1.0 : 0.0);
        if (is_type(args[1], vm->tp_str)) {
            const Str& s = CAST(Str&, args[1]);
            if(s == "inf") return VAR(INFINITY);
            if(s == "-inf") return VAR(-INFINITY);

            double float_out;
            char* p_end;
            try{
                float_out = std::strtod(s.data, &p_end);
                PK_ASSERT(p_end == s.end());
            }catch(...){
                vm->ValueError("invalid literal for float(): " + s.escape());
            }
            return VAR(float_out);
        }
        vm->TypeError("invalid arguments for float()");
        return vm->None;
    });

    _vm->bind__hash__(VM::tp_float, [](VM* vm, PyObject* _0) {
        f64 val = _CAST(f64, _0);
        return (i64)std::hash<f64>()(val);
    });

    _vm->bind__neg__(VM::tp_float, [](VM* vm, PyObject* _0) { return VAR(-_CAST(f64, _0)); });

    _vm->bind__repr__(VM::tp_float, [](VM* vm, PyObject* _0) {
        f64 val = _CAST(f64, _0);
        SStream ss;
        ss << val;
        return VAR(ss.str());
    });

    // tp_str
    _vm->bind_constructor<-1>(_vm->_t(VM::tp_str), [](VM* vm, ArgsView args) {
        if(args.size() == 1) return VAR(Str());
        if(args.size() > 2) vm->TypeError("str() takes at most 1 argument");
        return vm->py_str(args[1]);
    });

    _vm->bind__hash__(VM::tp_str, [](VM* vm, PyObject* _0) {
        return (i64)_CAST(Str&, _0).hash();
    });

    _vm->bind__add__(VM::tp_str, [](VM* vm, PyObject* _0, PyObject* _1) {
        return VAR(_CAST(Str&, _0) + CAST(Str&, _1));
    });
    _vm->bind__len__(VM::tp_str, [](VM* vm, PyObject* _0) {
        return (i64)_CAST(Str&, _0).u8_length();
    });
    _vm->bind__mul__(VM::tp_str, [](VM* vm, PyObject* _0, PyObject* _1) {
        const Str& self = _CAST(Str&, _0);
        i64 n = CAST(i64, _1);
        SStream ss;
        for(i64 i = 0; i < n; i++) ss << self.sv();
        return VAR(ss.str());
    });
    _vm->bind_method<1>(VM::tp_str, "__rmul__", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        i64 n = CAST(i64, args[1]);
        SStream ss;
        for(i64 i = 0; i < n; i++) ss << self.sv();
        return VAR(ss.str());
    });
    _vm->bind__contains__(VM::tp_str, [](VM* vm, PyObject* _0, PyObject* _1) {
        const Str& self = _CAST(Str&, _0);
        return VAR(self.index(CAST(Str&, _1)) != -1);
    });
    _vm->bind__str__(VM::tp_str, [](VM* vm, PyObject* _0) { return _0; });
    _vm->bind__iter__(VM::tp_str, [](VM* vm, PyObject* _0) { return VAR_T(StringIter, _0); });
    _vm->bind__repr__(VM::tp_str, [](VM* vm, PyObject* _0) {
        const Str& self = _CAST(Str&, _0);
        return VAR(self.escape());
    });

#define BIND_CMP_STR(name, op) \
    _vm->bind##name(VM::tp_str, [](VM* vm, PyObject* lhs, PyObject* rhs) { \
        if(!is_non_tagged_type(rhs, vm->tp_str)) return vm->NotImplemented; \
        return VAR(_CAST(Str&, lhs) op _CAST(Str&, rhs));                   \
    });

    BIND_CMP_STR(__eq__, ==)
    BIND_CMP_STR(__lt__, <)
    BIND_CMP_STR(__le__, <=)
    BIND_CMP_STR(__gt__, >)
    BIND_CMP_STR(__ge__, >=)
#undef BIND_CMP_STR

    _vm->bind__getitem__(VM::tp_str, [](VM* vm, PyObject* _0, PyObject* _1) {
        const Str& self = _CAST(Str&, _0);
        if(is_non_tagged_type(_1, vm->tp_slice)){
            const Slice& s = _CAST(Slice&, _1);
            int start, stop, step;
            vm->parse_int_slice(s, self.u8_length(), start, stop, step);
            return VAR(self.u8_slice(start, stop, step));
        }
        i64 i = CAST(i64, _1);
        i = vm->normalized_index(i, self.u8_length());
        return VAR(self.u8_getitem(i));
    });

    _vm->bind(_vm->_t(VM::tp_str), "replace(self, old, new, count=-1)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        const Str& old = CAST(Str&, args[1]);
        if(old.empty()) vm->ValueError("empty substring");
        const Str& new_ = CAST(Str&, args[2]);
        int count = CAST(int, args[3]);
        return VAR(self.replace(old, new_, count));
    });

    _vm->bind(_vm->_t(VM::tp_str), "split(self, sep=' ')", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        const Str& sep = CAST(Str&, args[1]);
        if(sep.empty()) vm->ValueError("empty separator");
        pod_vector<std::string_view> parts;
        if(sep.size == 1){
            parts = self.split(sep[0]);
        }else{
            parts = self.split(sep);
        }
        List ret(parts.size());
        for(int i=0; i<parts.size(); i++) ret[i] = VAR(Str(parts[i]));
        return VAR(std::move(ret));
    });

    _vm->bind(_vm->_t(VM::tp_str), "splitlines(self)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        pod_vector<std::string_view> parts;
        parts = self.split('\n');
        List ret(parts.size());
        for(int i=0; i<parts.size(); i++) ret[i] = VAR(Str(parts[i]));
        return VAR(std::move(ret));
    });

    _vm->bind(_vm->_t(VM::tp_str), "count(self, s: str)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        const Str& s = CAST(Str&, args[1]);
        return VAR(self.count(s));
    });

    _vm->bind(_vm->_t(VM::tp_str), "index(self, value, __start=0)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        const Str& value = CAST(Str&, args[1]);
        int start = CAST(int, args[2]);
        int index = self.index(value, start);
        if(index < 0) vm->ValueError("substring not found");
        return VAR(index);
    });

    _vm->bind(_vm->_t(VM::tp_str), "find(self, value, __start=0)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        const Str& value = CAST(Str&, args[1]);
        int start = CAST(int, args[2]);
        return VAR(self.index(value, start));
    });

    _vm->bind_method<1>(VM::tp_str, "startswith", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        const Str& prefix = CAST(Str&, args[1]);
        return VAR(self.index(prefix) == 0);
    });

    _vm->bind_method<1>(VM::tp_str, "endswith", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        const Str& suffix = CAST(Str&, args[1]);
        int offset = self.length() - suffix.length();
        if(offset < 0) return vm->False;
        bool ok = memcmp(self.data+offset, suffix.data, suffix.length()) == 0;
        return VAR(ok);
    });

    _vm->bind_method<0>(VM::tp_str, "encode", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        unsigned char* buffer = new unsigned char[self.length()];
        memcpy(buffer, self.data, self.length());
        return VAR(Bytes(buffer, self.length()));
    });

    _vm->bind_method<1>(VM::tp_str, "join", [](VM* vm, ArgsView args) {
        auto _lock = vm->heap.gc_scope_lock();
        const Str& self = _CAST(Str&, args[0]);
        SStream ss;
        PyObject* it = vm->py_iter(args[1]);     // strong ref
        PyObject* obj = vm->py_next(it);
        while(obj != vm->StopIteration){
            if(!ss.empty()) ss << self;
            ss << CAST(Str&, obj);
            obj = vm->py_next(it);
        }
        return VAR(ss.str());
    });

    _vm->bind_method<0>(VM::tp_str, "lower", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        return VAR(self.lower());
    });

    _vm->bind_method<0>(VM::tp_str, "upper", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        return VAR(self.upper());
    });

    _vm->bind(_vm->_t(VM::tp_str), "strip(self, chars=None)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        if(args[1] == vm->None){
            return VAR(self.strip());
        }else{
            const Str& chars = CAST(Str&, args[1]);
            return VAR(self.strip(true, true, chars));
        }
    });

    _vm->bind(_vm->_t(VM::tp_str), "lstrip(self, chars=None)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        if(args[1] == vm->None){
            return VAR(self.lstrip());
        }else{
            const Str& chars = CAST(Str&, args[1]);
            return VAR(self.strip(true, false, chars));
        }
    });

    _vm->bind(_vm->_t(VM::tp_str), "rstrip(self, chars=None)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        if(args[1] == vm->None){
            return VAR(self.rstrip());
        }else{
            const Str& chars = CAST(Str&, args[1]);
            return VAR(self.strip(false, true, chars));
        }
    });

    // zfill
    _vm->bind(_vm->_t(VM::tp_str), "zfill(self, width)", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        int width = CAST(int, args[1]);
        int delta = width - self.u8_length();
        if(delta <= 0) return args[0];
        SStream ss;
        for(int i=0; i<delta; i++) ss << '0';
        ss << self;
        return VAR(ss.str());
    });

    // ljust
    _vm->bind(_vm->_t(VM::tp_str), "ljust(self, width, fillchar=' ')", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        int width = CAST(int, args[1]);
        int delta = width - self.u8_length();
        if(delta <= 0) return args[0];
        const Str& fillchar = CAST(Str&, args[2]);
        SStream ss;
        ss << self;
        for(int i=0; i<delta; i++) ss << fillchar;
        return VAR(ss.str());
    });

    // rjust
    _vm->bind(_vm->_t(VM::tp_str), "rjust(self, width, fillchar=' ')", [](VM* vm, ArgsView args) {
        const Str& self = _CAST(Str&, args[0]);
        int width = CAST(int, args[1]);
        int delta = width - self.u8_length();
        if(delta <= 0) return args[0];
        const Str& fillchar = CAST(Str&, args[2]);
        SStream ss;
        for(int i=0; i<delta; i++) ss << fillchar;
        ss << self;
        return VAR(ss.str());
    });

    // tp_list / tp_tuple
    _vm->bind(_vm->_t(VM::tp_list), "sort(self, key=None, reverse=False)", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        PyObject* key = args[1];
        if(key == vm->None){
            std::stable_sort(self.begin(), self.end(), [vm](PyObject* a, PyObject* b){
                return vm->py_lt(a, b);
            });
        }else{
            std::stable_sort(self.begin(), self.end(), [vm, key](PyObject* a, PyObject* b){
                return vm->py_lt(vm->call(key, a), vm->call(key, b));
            });
        }
        bool reverse = CAST(bool, args[2]);
        if(reverse) self.reverse();
        return vm->None;
    });

    _vm->bind__repr__(VM::tp_list, [](VM* vm, PyObject* _0){
        if(vm->_repr_recursion_set.count(_0)) return VAR("[...]");
        List& iterable = _CAST(List&, _0);
        SStream ss;
        ss << '[';
        vm->_repr_recursion_set.insert(_0);
        for(int i=0; i<iterable.size(); i++){
            ss << CAST(Str&, vm->py_repr(iterable[i]));
            if(i != iterable.size()-1) ss << ", ";
        }
        vm->_repr_recursion_set.erase(_0);
        ss << ']';
        return VAR(ss.str());
    });

    _vm->bind__repr__(VM::tp_tuple, [](VM* vm, PyObject* _0){
        Tuple& iterable = _CAST(Tuple&, _0);
        SStream ss;
        ss << '(';
        if(iterable.size() == 1){
            ss << CAST(Str&, vm->py_repr(iterable[0]));
            ss << ',';
        }else{
            for(int i=0; i<iterable.size(); i++){
                ss << CAST(Str&, vm->py_repr(iterable[i]));
                if(i != iterable.size()-1) ss << ", ";
            }
        }
        ss << ')';
        return VAR(ss.str());
    });

    _vm->bind_constructor<-1>(_vm->_t(VM::tp_list), [](VM* vm, ArgsView args) {
        if(args.size() == 1+0) return VAR(List());
        if(args.size() == 1+1) return vm->py_list(args[1]);
        vm->TypeError("list() takes 0 or 1 arguments");
        return vm->None;
    });

    _vm->bind__contains__(VM::tp_list, [](VM* vm, PyObject* _0, PyObject* _1) {
        List& self = _CAST(List&, _0);
        for(PyObject* i: self) if(vm->py_eq(i, _1)) return vm->True;
        return vm->False;
    });

    _vm->bind_method<1>(VM::tp_list, "count", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        int count = 0;
        for(PyObject* i: self) if(vm->py_eq(i, args[1])) count++;
        return VAR(count);
    });

    _vm->bind__eq__(VM::tp_list, [](VM* vm, PyObject* _0, PyObject* _1) {
        List& a = _CAST(List&, _0);
        if(!is_non_tagged_type(_1, vm->tp_list)) return vm->NotImplemented;
        List& b = _CAST(List&, _1);
        if(a.size() != b.size()) return vm->False;
        for(int i=0; i<a.size(); i++){
            if(!vm->py_eq(a[i], b[i])) return vm->False;
        }
        return vm->True;
    });

    _vm->bind(_vm->_t(VM::tp_list), "index(self, value, __start=0)", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        PyObject* obj = args[1];
        int start = CAST(int, args[2]);
        for(int i=start; i<self.size(); i++){
            if(vm->py_eq(self[i], obj)) return VAR(i);
        }
        vm->ValueError(_CAST(Str&, vm->py_repr(obj)) + " is not in list");
        return vm->None;
    });

    _vm->bind_method<1>(VM::tp_list, "remove", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        PyObject* obj = args[1];
        for(int i=0; i<self.size(); i++){
            if(vm->py_eq(self[i], obj)){
                self.erase(i);
                return vm->None;
            }
        }
        vm->ValueError(_CAST(Str&, vm->py_repr(obj)) + " is not in list");
        return vm->None;
    });

    _vm->bind_method<-1>(VM::tp_list, "pop", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        if(args.size() == 1+0){
            if(self.empty()) vm->IndexError("pop from empty list");
            return self.popx_back();
        }
        if(args.size() == 1+1){
            i64 index = CAST(i64, args[1]);
            index = vm->normalized_index(index, self.size());
            PyObject* ret = self[index];
            self.erase(index);
            return ret;
        }
        vm->TypeError("pop() takes at most 1 argument");
        return vm->None;
    });

    _vm->bind_method<1>(VM::tp_list, "append", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        self.push_back(args[1]);
        return vm->None;
    });

    _vm->bind_method<1>(VM::tp_list, "extend", [](VM* vm, ArgsView args) {
        auto _lock = vm->heap.gc_scope_lock();
        List& self = _CAST(List&, args[0]);
        PyObject* it = vm->py_iter(args[1]);     // strong ref
        PyObject* obj = vm->py_next(it);
        while(obj != vm->StopIteration){
            self.push_back(obj);
            obj = vm->py_next(it);
        }
        return vm->None;
    });

    _vm->bind_method<0>(VM::tp_list, "reverse", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        std::reverse(self.begin(), self.end());
        return vm->None;
    });

    _vm->bind__mul__(VM::tp_list, [](VM* vm, PyObject* _0, PyObject* _1) {
        const List& self = _CAST(List&, _0);
        if(!is_int(_1)) return vm->NotImplemented;
        int n = _CAST(int, _1);
        List result;
        result.reserve(self.size() * n);
        for(int i = 0; i < n; i++) result.extend(self);
        return VAR(std::move(result));
    });
    _vm->bind_method<1>(VM::tp_list, "__rmul__", [](VM* vm, ArgsView args) {
        const List& self = _CAST(List&, args[0]);
        if(!is_int(args[1])) return vm->NotImplemented;
        int n = _CAST(int, args[1]);
        List result;
        result.reserve(self.size() * n);
        for(int i = 0; i < n; i++) result.extend(self);
        return VAR(std::move(result));
    });

    _vm->bind_method<2>(VM::tp_list, "insert", [](VM* vm, ArgsView args) {
        List& self = _CAST(List&, args[0]);
        int index = CAST(int, args[1]);
        if(index < 0) index += self.size();
        if(index < 0) index = 0;
        if(index > self.size()) index = self.size();
        self.insert(index, args[2]);
        return vm->None;
    });

    _vm->bind_method<0>(VM::tp_list, "clear", [](VM* vm, ArgsView args) {
        _CAST(List&, args[0]).clear();
        return vm->None;
    });

    _vm->bind_method<0>(VM::tp_list, "copy", PK_LAMBDA(VAR(_CAST(List, args[0]))));

#define BIND_RICH_CMP(name, op, _t, _T)    \
    _vm->bind__##name##__(_vm->_t, [](VM* vm, PyObject* lhs, PyObject* rhs){        \
        if(!is_non_tagged_type(rhs, vm->_t)) return vm->NotImplemented;             \
        auto& a = _CAST(_T&, lhs);                                                  \
        auto& b = _CAST(_T&, rhs);                                                  \
        for(int i=0; i<a.size() && i<b.size(); i++){                                \
            if(vm->py_eq(a[i], b[i])) continue;                                     \
            return VAR(vm->py_##name(a[i], b[i]));                                  \
        }                                                                           \
        return VAR(a.size() op b.size());                                           \
    });

    BIND_RICH_CMP(lt, <, tp_list, List)
    BIND_RICH_CMP(le, <=, tp_list, List)
    BIND_RICH_CMP(gt, >, tp_list, List)
    BIND_RICH_CMP(ge, >=, tp_list, List)

    BIND_RICH_CMP(lt, <, tp_tuple, Tuple)
    BIND_RICH_CMP(le, <=, tp_tuple, Tuple)
    BIND_RICH_CMP(gt, >, tp_tuple, Tuple)
    BIND_RICH_CMP(ge, >=, tp_tuple, Tuple)

#undef BIND_RICH_CMP

    _vm->bind__add__(VM::tp_list, [](VM* vm, PyObject* _0, PyObject* _1) {
        const List& self = _CAST(List&, _0);
        const List& other = CAST(List&, _1);
        List new_list(self);    // copy construct
        new_list.extend(other);
        return VAR(std::move(new_list));
    });

    _vm->bind__len__(VM::tp_list, [](VM* vm, PyObject* _0) {
        return (i64)_CAST(List&, _0).size();
    });
    _vm->bind__iter__(VM::tp_list, [](VM* vm, PyObject* _0) {
        List& self = _CAST(List&, _0);
        return VAR_T(ArrayIter, _0, self.begin(), self.end());
    });
    _vm->bind__getitem__(VM::tp_list, PyArrayGetItem<List>);
    _vm->bind__setitem__(VM::tp_list, [](VM* vm, PyObject* _0, PyObject* _1, PyObject* _2){
        List& self = _CAST(List&, _0);
        i64 i = CAST(i64, _1);
        i = vm->normalized_index(i, self.size());
        self[i] = _2;
    });
    _vm->bind__delitem__(VM::tp_list, [](VM* vm, PyObject* _0, PyObject* _1){
        List& self = _CAST(List&, _0);
        i64 i = CAST(i64, _1);
        i = vm->normalized_index(i, self.size());
        self.erase(i);
    });

    _vm->bind_constructor<-1>(_vm->_t(VM::tp_tuple), [](VM* vm, ArgsView args) {
        if(args.size() == 1+0) return VAR(Tuple(0));
        if(args.size() == 1+1){
            List list(CAST(List, vm->py_list(args[1])));
            return VAR(Tuple(std::move(list)));
        }
        vm->TypeError("tuple() takes at most 1 argument");
        return vm->None;
    });

    _vm->bind__contains__(VM::tp_tuple, [](VM* vm, PyObject* obj, PyObject* item) {
        Tuple& self = _CAST(Tuple&, obj);
        for(PyObject* i: self) if(vm->py_eq(i, item)) return vm->True;
        return vm->False;
    });

    _vm->bind_method<1>(VM::tp_tuple, "count", [](VM* vm, ArgsView args) {
        Tuple& self = _CAST(Tuple&, args[0]);
        int count = 0;
        for(PyObject* i: self) if(vm->py_eq(i, args[1])) count++;
        return VAR(count);
    });

    _vm->bind__eq__(VM::tp_tuple, [](VM* vm, PyObject* _0, PyObject* _1) {
        const Tuple& self = _CAST(Tuple&, _0);
        if(!is_non_tagged_type(_1, vm->tp_tuple)) return vm->NotImplemented;
        const Tuple& other = _CAST(Tuple&, _1);
        if(self.size() != other.size()) return vm->False;
        for(int i = 0; i < self.size(); i++) {
            if(!vm->py_eq(self[i], other[i])) return vm->False;
        }
        return vm->True;
    });

    _vm->bind__hash__(VM::tp_tuple, [](VM* vm, PyObject* _0) {
        i64 x = 1000003;
        for (PyObject* item: _CAST(Tuple&, _0)) {
            i64 y = vm->py_hash(item);
            // recommended by Github Copilot
            x = x ^ (y + 0x9e3779b9 + (x << 6) + (x >> 2));
        }
        return x;
    });

    _vm->bind__iter__(VM::tp_tuple, [](VM* vm, PyObject* _0) {
        Tuple& self = _CAST(Tuple&, _0);
        return VAR_T(ArrayIter, _0, self.begin(), self.end());
    });
    _vm->bind__getitem__(VM::tp_tuple, PyArrayGetItem<Tuple>);
    _vm->bind__len__(VM::tp_tuple, [](VM* vm, PyObject* obj) {
        return (i64)_CAST(Tuple&, obj).size();
    });

    // tp_bool
    _vm->bind_constructor<2>(_vm->_t(VM::tp_bool), PK_LAMBDA(VAR(vm->py_bool(args[1]))));
    _vm->bind__hash__(VM::tp_bool, [](VM* vm, PyObject* _0) {
        return (i64)_CAST(bool, _0);
    });
    _vm->bind__repr__(VM::tp_bool, [](VM* vm, PyObject* _0) {
        bool val = _CAST(bool, _0);
        return VAR(val ? "True" : "False");
    });

    _vm->bind__and__(VM::tp_bool, [](VM* vm, PyObject* _0, PyObject* _1) {
        return VAR(_CAST(bool, _0) && CAST(bool, _1));
    });
    _vm->bind__or__(VM::tp_bool, [](VM* vm, PyObject* _0, PyObject* _1) {
        return VAR(_CAST(bool, _0) || CAST(bool, _1));
    });
    _vm->bind__xor__(VM::tp_bool, [](VM* vm, PyObject* _0, PyObject* _1) {
        return VAR(_CAST(bool, _0) != CAST(bool, _1));
    });
    _vm->bind__eq__(VM::tp_bool, [](VM* vm, PyObject* _0, PyObject* _1) {
        if(is_non_tagged_type(_1, vm->tp_bool)) return VAR(_0 == _1);
        if(is_int(_1)) return VAR(_CAST(bool, _0) == (bool)CAST(i64, _1));
        return vm->NotImplemented;
    });

    // tp_ellipsis / tp_NotImplementedType
    _vm->bind__repr__(_vm->_tp(_vm->Ellipsis), [](VM* vm, PyObject* _0) {
        return VAR("...");
    });
    _vm->bind__repr__(_vm->_tp(_vm->NotImplemented), [](VM* vm, PyObject* _0) {
        return VAR("NotImplemented");
    });

    // tp_bytes
    _vm->bind_constructor<2>(_vm->_t(VM::tp_bytes), [](VM* vm, ArgsView args){
        List& list = CAST(List&, args[1]);
        unsigned char* buffer = new unsigned char[list.size()];
        for(int i=0; i<list.size(); i++){
            i64 b = CAST(i64, list[i]);
            if(b<0 || b>255) vm->ValueError("byte must be in range[0, 256)");
            buffer[i] = (char)b;
        }
        return VAR(Bytes(buffer, list.size()));
    });

    _vm->bind__getitem__(VM::tp_bytes, [](VM* vm, PyObject* obj, PyObject* index) {
        const Bytes& self = _CAST(Bytes&, obj);
        i64 i = CAST(i64, index);
        i = vm->normalized_index(i, self.size());
        return VAR(self[i]);
    });

    _vm->bind__hash__(VM::tp_bytes, [](VM* vm, PyObject* _0) {
        const Bytes& self = _CAST(Bytes&, _0);
        std::string_view view((char*)self.data(), self.size());
        return (i64)std::hash<std::string_view>()(view);
    });

    _vm->bind__repr__(VM::tp_bytes, [](VM* vm, PyObject* _0) {
        const Bytes& self = _CAST(Bytes&, _0);
        SStream ss;
        ss << "b'";
        for(int i=0; i<self.size(); i++){
            ss << "\\x";
            ss.write_hex((unsigned char)self[i]);
        }
        ss << "'";
        return VAR(ss.str());
    });
    _vm->bind__len__(VM::tp_bytes, [](VM* vm, PyObject* _0) {
        return (i64)_CAST(Bytes&, _0).size();
    });

    _vm->bind_method<0>(VM::tp_bytes, "decode", [](VM* vm, ArgsView args) {
        const Bytes& self = _CAST(Bytes&, args[0]);
        // TODO: check encoding is utf-8
        return VAR(Str(self.str()));
    });

    _vm->bind__eq__(VM::tp_bytes, [](VM* vm, PyObject* _0, PyObject* _1) {
        if(!is_non_tagged_type(_1, vm->tp_bytes)) return vm->NotImplemented;
        return VAR(_CAST(Bytes&, _0) == _CAST(Bytes&, _1));
    });
    
    // tp_slice
    _vm->bind_constructor<4>(_vm->_t(VM::tp_slice), [](VM* vm, ArgsView args) {
        return VAR(Slice(args[1], args[2], args[3]));
    });

    _vm->bind__eq__(VM::tp_slice, [](VM* vm, PyObject* _0, PyObject* _1){
        const Slice& self = _CAST(Slice&, _0);
        if(!is_non_tagged_type(_1, vm->tp_slice)) return vm->NotImplemented;
        const Slice& other = _CAST(Slice&, _1);
        if(vm->py_ne(self.start, other.start)) return vm->False;
        if(vm->py_ne(self.stop, other.stop)) return vm->False;
        if(vm->py_ne(self.step, other.step)) return vm->False;
        return vm->True;
    });

    _vm->bind__repr__(VM::tp_slice, [](VM* vm, PyObject* _0) {
        const Slice& self = _CAST(Slice&, _0);
        SStream ss;
        ss << "slice(";
        ss << CAST(Str, vm->py_repr(self.start)) << ", ";
        ss << CAST(Str, vm->py_repr(self.stop)) << ", ";
        ss << CAST(Str, vm->py_repr(self.step)) << ")";
        return VAR(ss.str());
    });

    // tp_mappingproxy
    _vm->bind_method<0>(VM::tp_mappingproxy, "keys", [](VM* vm, ArgsView args) {
        MappingProxy& self = _CAST(MappingProxy&, args[0]);
        List keys;
        for(StrName name : self.attr().keys()) keys.push_back(VAR(name.sv()));
        return VAR(std::move(keys));
    });

    _vm->bind_method<0>(VM::tp_mappingproxy, "values", [](VM* vm, ArgsView args) {
        MappingProxy& self = _CAST(MappingProxy&, args[0]);
        List values;
        for(auto [k, v] : self.attr().items()) values.push_back(v);
        return VAR(std::move(values));
    });

    _vm->bind_method<0>(VM::tp_mappingproxy, "items", [](VM* vm, ArgsView args) {
        MappingProxy& self = _CAST(MappingProxy&, args[0]);
        List items;
        for(auto [k, v] : self.attr().items()){
            PyObject* t = VAR(Tuple(VAR(k.sv()), v));
            items.push_back(std::move(t));
        }
        return VAR(std::move(items));
    });

    _vm->bind__len__(VM::tp_mappingproxy, [](VM* vm, PyObject* _0) {
        return (i64)_CAST(MappingProxy&, _0).attr().size();
    });

    _vm->bind__eq__(VM::tp_mappingproxy, [](VM* vm, PyObject* _0, PyObject* _1){
        const MappingProxy& a = _CAST(MappingProxy&, _0);
        if(!is_non_tagged_type(_1, vm->tp_mappingproxy)) return vm->NotImplemented;
        const MappingProxy& b = _CAST(MappingProxy&, _1);
        return VAR(a.obj == b.obj);
    });

    _vm->bind__getitem__(VM::tp_mappingproxy, [](VM* vm, PyObject* _0, PyObject* _1) {
        MappingProxy& self = _CAST(MappingProxy&, _0);
        StrName key = CAST(Str&, _1);
        PyObject* ret = self.attr().try_get_likely_found(key);
        if(ret == nullptr) vm->KeyError(_1);
        return ret;
    });

    _vm->bind(_vm->_t(VM::tp_mappingproxy), "get(self, key, default=None)", [](VM* vm, ArgsView args) {
        MappingProxy& self = _CAST(MappingProxy&, args[0]);
        StrName key = CAST(Str&, args[1]);
        PyObject* ret = self.attr().try_get(key);
        if(ret == nullptr) return args[2];
        return ret;
    });

    _vm->bind__repr__(VM::tp_mappingproxy, [](VM* vm, PyObject* _0) {
        if(vm->_repr_recursion_set.count(_0)) return VAR("{...}");
        MappingProxy& self = _CAST(MappingProxy&, _0);
        SStream ss;
        ss << "mappingproxy({";
        bool first = true;
        vm->_repr_recursion_set.insert(_0);
        for(auto [k, v] : self.attr().items()){
            if(!first) ss << ", ";
            first = false;
            ss << k.escape() << ": ";
            ss << CAST(Str, vm->py_repr(v));
        }
        vm->_repr_recursion_set.erase(_0);
        ss << "})";
        return VAR(ss.str());
    });

    _vm->bind__contains__(VM::tp_mappingproxy, [](VM* vm, PyObject* _0, PyObject* _1) {
        MappingProxy& self = _CAST(MappingProxy&, _0);
        return VAR(self.attr().contains(CAST(Str&, _1)));
    });

    // tp_dict
    _vm->bind_constructor<-1>(_vm->_t(VM::tp_dict), [](VM* vm, ArgsView args){
        return VAR(Dict(vm));
    });

    _vm->bind_method<-1>(VM::tp_dict, "__init__", [](VM* vm, ArgsView args){
        if(args.size() == 1+0) return vm->None;
        if(args.size() == 1+1){
            auto _lock = vm->heap.gc_scope_lock();
            Dict& self = _CAST(Dict&, args[0]);
            List& list = CAST(List&, args[1]);
            for(PyObject* item : list){
                Tuple& t = CAST(Tuple&, item);
                if(t.size() != 2){
                    vm->ValueError("dict() takes an iterable of tuples (key, value)");
                    return vm->None;
                }
                self.set(t[0], t[1]);
            }
            return vm->None;
        }
        vm->TypeError("dict() takes at most 1 argument");
        return vm->None;
    });

    _vm->bind__len__(VM::tp_dict, [](VM* vm, PyObject* _0) {
        return (i64)_CAST(Dict&, _0).size();
    });

    _vm->bind__getitem__(VM::tp_dict, [](VM* vm, PyObject* _0, PyObject* _1) {
        Dict& self = _CAST(Dict&, _0);
        PyObject* ret = self.try_get(_1);
        if(ret == nullptr) vm->KeyError(_1);
        return ret;
    });

    _vm->bind__setitem__(VM::tp_dict, [](VM* vm, PyObject* _0, PyObject* _1, PyObject* _2) {
        Dict& self = _CAST(Dict&, _0);
        self.set(_1, _2);
    });

    _vm->bind__delitem__(VM::tp_dict, [](VM* vm, PyObject* _0, PyObject* _1) {
        Dict& self = _CAST(Dict&, _0);
        bool ok = self.erase(_1);
        if(!ok) vm->KeyError(_1);
    });

    _vm->bind_method<-1>(VM::tp_dict, "pop", [](VM* vm, ArgsView args) {
        if(args.size() != 2 && args.size() != 3){
            vm->TypeError("pop() expected 1 or 2 arguments");
            return vm->None;
        }
        Dict& self = _CAST(Dict&, args[0]);
        PyObject* value = self.try_get(args[1]);
        if(value == nullptr){
            if(args.size() == 2) vm->KeyError(args[1]);
            if(args.size() == 3){
                return args[2];
            }
        }
        self.erase(args[1]);
        return value;
    });

    _vm->bind__contains__(VM::tp_dict, [](VM* vm, PyObject* _0, PyObject* _1) {
        Dict& self = _CAST(Dict&, _0);
        return VAR(self.contains(_1));
    });

    _vm->bind__iter__(VM::tp_dict, [](VM* vm, PyObject* _0) {
        const Dict& self = _CAST(Dict&, _0);
        return vm->py_iter(VAR(self.keys()));
    });

    _vm->bind_method<-1>(VM::tp_dict, "get", [](VM* vm, ArgsView args) {
        Dict& self = _CAST(Dict&, args[0]);
        if(args.size() == 1+1){
            PyObject* ret = self.try_get(args[1]);
            if(ret != nullptr) return ret;
            return vm->None;
        }else if(args.size() == 1+2){
            PyObject* ret = self.try_get(args[1]);
            if(ret != nullptr) return ret;
            return args[2];
        }
        vm->TypeError("get() takes at most 2 arguments");
        return vm->None;
    });

    _vm->bind_method<0>(VM::tp_dict, "keys", [](VM* vm, ArgsView args) {
        const Dict& self = _CAST(Dict&, args[0]);
        return VAR(self.keys());
    });

    _vm->bind_method<0>(VM::tp_dict, "values", [](VM* vm, ArgsView args) {
        const Dict& self = _CAST(Dict&, args[0]);
        return VAR(self.values());
    });

    _vm->bind_method<0>(VM::tp_dict, "items", [](VM* vm, ArgsView args) {
        const Dict& self = _CAST(Dict&, args[0]);
        Tuple items(self.size());
        int j = 0;
        self.apply([&](PyObject* k, PyObject* v){
            items[j++] = VAR(Tuple(k, v));
        });
        return VAR(std::move(items));
    });

    _vm->bind_method<1>(VM::tp_dict, "update", [](VM* vm, ArgsView args) {
        Dict& self = _CAST(Dict&, args[0]);
        const Dict& other = CAST(Dict&, args[1]);
        self.update(other);
        return vm->None;
    });

    _vm->bind_method<0>(VM::tp_dict, "copy", [](VM* vm, ArgsView args) {
        const Dict& self = _CAST(Dict&, args[0]);
        return VAR(self);
    });

    _vm->bind_method<0>(VM::tp_dict, "clear", [](VM* vm, ArgsView args) {
        Dict& self = _CAST(Dict&, args[0]);
        self.clear();
        return vm->None;
    });

    _vm->bind__repr__(VM::tp_dict, [](VM* vm, PyObject* _0) {
        if(vm->_repr_recursion_set.count(_0)) return VAR("{...}");
        Dict& self = _CAST(Dict&, _0);
        SStream ss;
        ss << "{";
        bool first = true;
        vm->_repr_recursion_set.insert(_0);
        self.apply([&](PyObject* k, PyObject* v){
            if(!first) ss << ", ";
            first = false;
            ss << CAST(Str&, vm->py_repr(k)) << ": " << CAST(Str&, vm->py_repr(v));
        });
        vm->_repr_recursion_set.erase(_0);
        ss << "}";
        return VAR(ss.str());
    });

    _vm->bind__eq__(VM::tp_dict, [](VM* vm, PyObject* _0, PyObject* _1) {
        Dict& self = _CAST(Dict&, _0);
        if(!is_non_tagged_type(_1, vm->tp_dict)) return vm->NotImplemented;
        Dict& other = _CAST(Dict&, _1);
        if(self.size() != other.size()) return vm->False;
        for(int i=0; i<self._capacity; i++){
            auto item = self._items[i];
            if(item.first == nullptr) continue;
            PyObject* value = other.try_get(item.first);
            if(value == nullptr) return vm->False;
            if(!vm->py_eq(item.second, value)) return vm->False;
        }
        return vm->True;
    });

    _vm->bind__repr__(VM::tp_module, [](VM* vm, PyObject* _0) {
        const Str& path = CAST(Str&, _0->attr(__path__));
        return VAR(_S("<module ", path.escape(), ">"));
    });

    // tp_property
    _vm->bind_constructor<-1>(_vm->_t(VM::tp_property), [](VM* vm, ArgsView args) {
        if(args.size() == 1+1){
            return VAR(Property(args[1], vm->None, ""));
        }else if(args.size() == 1+2){
            return VAR(Property(args[1], args[2], ""));
        }else if(args.size() == 1+3){
            return VAR(Property(args[1], args[2], CAST(Str, args[3])));
        }
        vm->TypeError("property() takes at most 3 arguments");
        return vm->None;
    });

    // properties
    _vm->bind_property(_vm->_t(VM::tp_property), "__signature__", [](VM* vm, ArgsView args){
        Property& self = _CAST(Property&, args[0]);
        return VAR(self.signature);
    });
    
    _vm->bind_property(_vm->_t(VM::tp_function), "__doc__", [](VM* vm, ArgsView args) {
        Function& func = _CAST(Function&, args[0]);
        return VAR(func.decl->docstring);
    });

    _vm->bind_property(_vm->_t(VM::tp_native_func), "__doc__", [](VM* vm, ArgsView args) {
        NativeFunc& func = _CAST(NativeFunc&, args[0]);
        if(func.decl != nullptr) return VAR(func.decl->docstring);
        return VAR("");
    });

    _vm->bind_property(_vm->_t(VM::tp_function), "__signature__", [](VM* vm, ArgsView args) {
        Function& func = _CAST(Function&, args[0]);
        return VAR(func.decl->signature);
    });

    _vm->bind_property(_vm->_t(VM::tp_native_func), "__signature__", [](VM* vm, ArgsView args) {
        NativeFunc& func = _CAST(NativeFunc&, args[0]);
        if(func.decl != nullptr) return VAR(func.decl->signature);
        return VAR("");
    });

    // tp_exception
    _vm->bind_constructor<-1>(_vm->_t(VM::tp_exception), [](VM* vm, ArgsView args){
        Type cls = PK_OBJ_GET(Type, args[0]);
        StrName cls_name = _type_name(vm, cls);
        PyObject* e_obj = vm->heap.gcnew<Exception>(cls, cls_name);
        e_obj->_enable_instance_dict();
        PK_OBJ_GET(Exception, e_obj)._self = e_obj;
        return e_obj;
    });

    _vm->bind(_vm->_t(VM::tp_exception), "__init__(self, msg=...)", [](VM* vm, ArgsView args){
        Exception& self = _CAST(Exception&, args[0]);
        if(args[1] == vm->Ellipsis){
            self.msg = "";
        }else{
            self.msg = CAST(Str, args[1]);
        }
        return vm->None;
    });

    _vm->bind__repr__(VM::tp_exception, [](VM* vm, PyObject* _0) {
        Exception& self = _CAST(Exception&, _0);
        return VAR(_S(_type_name(vm, _0->type), '(', self.msg.escape(), ')'));
    });

    _vm->bind__str__(VM::tp_exception, [](VM* vm, PyObject* _0) {
        Exception& self = _CAST(Exception&, _0);
        return VAR(self.msg);
    });

    RangeIter::register_class(_vm, _vm->builtins);
    ArrayIter::register_class(_vm, _vm->builtins);
    StringIter::register_class(_vm, _vm->builtins);
    Generator::register_class(_vm, _vm->builtins);
}

void VM::post_init(){
    init_builtins(this);

    bind_method<-1>(tp_module, "__init__", [](VM* vm, ArgsView args) {
        vm->NotImplementedError();
        return vm->None;
    });

    _all_types[tp_module].m__getattr__ = [](VM* vm, PyObject* obj, StrName name) -> PyObject*{
        const Str& path = CAST(Str&, obj->attr(__path__));
        return vm->py_import(_S(path, ".", name.sv()), false);
    };

    bind_method<1>(tp_property, "setter", [](VM* vm, ArgsView args) {
        Property& self = _CAST(Property&, args[0]);
        // The setter's name is not necessary to be the same as the property's name
        // However, for cpython compatibility, we recommend to use the same name
        self.setter = args[1];
        return args[0];
    });

    // type
    bind__getitem__(tp_type, [](VM* vm, PyObject* self, PyObject* _){
        return self;        // for generics
    });

    bind__repr__(tp_type, [](VM* vm, PyObject* self){
        SStream ss;
        const PyTypeInfo& info = vm->_all_types[PK_OBJ_GET(Type, self)];
        ss << "<class '" << info.name << "'>";
        return VAR(ss.str());
    });

    bind_property(_t(tp_object), "__class__", PK_LAMBDA(vm->_t(args[0])));
    bind_property(_t(tp_type), "__base__", [](VM* vm, ArgsView args){
        const PyTypeInfo& info = vm->_all_types[PK_OBJ_GET(Type, args[0])];
        return info.base.index == -1 ? vm->None : vm->_all_types[info.base].obj;
    });
    bind_property(_t(tp_type), "__name__", [](VM* vm, ArgsView args){
        const PyTypeInfo& info = vm->_all_types[PK_OBJ_GET(Type, args[0])];
        return VAR(info.name.sv());
    });
    bind_property(_t(tp_type), "__module__", [](VM* vm, ArgsView args){
        const PyTypeInfo& info = vm->_all_types[PK_OBJ_GET(Type, args[0])];
        if(info.mod == nullptr) return vm->None;
        return info.mod;
    });
    bind_property(_t(tp_bound_method), "__self__", [](VM* vm, ArgsView args){
        return CAST(BoundMethod&, args[0]).self;
    });
    bind_property(_t(tp_bound_method), "__func__", [](VM* vm, ArgsView args){
        return CAST(BoundMethod&, args[0]).func;
    });

    bind__eq__(tp_bound_method, [](VM* vm, PyObject* lhs, PyObject* rhs){
        if(!is_non_tagged_type(rhs, vm->tp_bound_method)) return vm->NotImplemented;
        const BoundMethod& _0 = PK_OBJ_GET(BoundMethod, lhs);
        const BoundMethod& _1 = PK_OBJ_GET(BoundMethod, rhs);
        return VAR(_0.self == _1.self && _0.func == _1.func);
    });

    bind_property(_t(tp_slice), "start", [](VM* vm, ArgsView args){
        return CAST(Slice&, args[0]).start;
    });
    bind_property(_t(tp_slice), "stop", [](VM* vm, ArgsView args){
        return CAST(Slice&, args[0]).stop;
    });
    bind_property(_t(tp_slice), "step", [](VM* vm, ArgsView args){
        return CAST(Slice&, args[0]).step;
    });

    bind_property(_t(tp_object), "__dict__", [](VM* vm, ArgsView args){
        if(is_tagged(args[0]) || !args[0]->is_attr_valid()) return vm->None;
        return VAR(MappingProxy(args[0]));
    });

    add_module_sys(this);
    add_module_traceback(this);
    add_module_time(this);
    add_module_json(this);
    add_module_math(this);
    add_module_dis(this);
    add_module_c(this);
    add_module_gc(this);
    add_module_random(this);
    add_module_base64(this);
    add_module_operator(this);

    for(const char* name: {"this", "functools", "heapq", "bisect", "pickle", "_long", "colorsys", "typing", "datetime", "cmath"}){
        _lazy_modules[name] = kPythonLibs[name];
    }

    try{
        CodeObject_ code = compile(kPythonLibs["builtins"], "<builtins>", EXEC_MODE);
        this->_exec(code, this->builtins);
        code = compile(kPythonLibs["_set"], "<set>", EXEC_MODE);
        this->_exec(code, this->builtins);
    }catch(const Exception& e){
        std::cerr << e.summary() << std::endl;
        std::cerr << "failed to load builtins module!!" << std::endl;
        exit(1);
    }

    if(enable_os){
        add_module_io(this);
        add_module_os(this);
        _import_handler = _default_import_handler;
    }

    add_module_csv(this);
    add_module_dataclasses(this);
    add_module_linalg(this);
    add_module_easing(this);
    add_module_collections(this);
    add_module_array2d(this);
    add_module_line_profiler(this);

#ifdef PK_USE_CJSON
    add_module_cjson(this);
#endif
}

CodeObject_ VM::compile(std::string_view source, const Str& filename, CompileMode mode, bool unknown_global_scope) {
    Compiler compiler(this, source, filename, mode, unknown_global_scope);
    try{
        return compiler.compile();
    }catch(const Exception& e){
#if PK_DEBUG_FULL_EXCEPTION
        std::cerr << e.summary() << std::endl;
#endif
        _error(e.self());
        return nullptr;
    }
}

}   // namespace pkpy