From ef9c5c98cc0ef6f0377302903981620237e7e486 Mon Sep 17 00:00:00 2001
From: blueloveTH <blueloveth@foxmail.com>
Date: Fri, 16 Aug 2024 15:53:10 +0800
Subject: [PATCH] add `enum` module

---
 include/pocketpy/common/_generated.h   |  1 -
 include/pocketpy/interpreter/modules.h |  3 +-
 include/pocketpy/interpreter/vm.h      |  1 -
 include/pocketpy/pocketpy.h            |  4 ++
 python/_enum.py                        | 11 ----
 src/common/_generated.c                |  1 -
 src/interpreter/vm.c                   |  2 +-
 src/modules/enum.c                     | 91 ++++++++++++++++++++++++++
 src/public/internal.c                  | 14 ++--
 src/public/py_exception.c              |  1 -
 src/public/py_ops.c                    |  9 +--
 src/public/stack_ops.c                 | 11 ++++
 tests/{90_enum.py => 82_enum.py}       |  2 -
 13 files changed, 119 insertions(+), 32 deletions(-)
 delete mode 100644 python/_enum.py
 create mode 100644 src/modules/enum.c
 rename tests/{90_enum.py => 82_enum.py} (98%)

diff --git a/include/pocketpy/common/_generated.h b/include/pocketpy/common/_generated.h
index 641b93fd..472043fc 100644
--- a/include/pocketpy/common/_generated.h
+++ b/include/pocketpy/common/_generated.h
@@ -3,7 +3,6 @@
 
 const char* load_kPythonLib(const char* name);
 
-extern const char kPythonLibs__enum[];
 extern const char kPythonLibs_bisect[];
 extern const char kPythonLibs_builtins[];
 extern const char kPythonLibs_cmath[];
diff --git a/include/pocketpy/interpreter/modules.h b/include/pocketpy/interpreter/modules.h
index c9971602..f7588be2 100644
--- a/include/pocketpy/interpreter/modules.h
+++ b/include/pocketpy/interpreter/modules.h
@@ -10,4 +10,5 @@ void pk__add_module_json();
 void pk__add_module_gc();
 void pk__add_module_time();
 void pk__add_module_easing();
-void pk__add_module_traceback();
\ No newline at end of file
+void pk__add_module_traceback();
+void pk__add_module_enum();
\ No newline at end of file
diff --git a/include/pocketpy/interpreter/vm.h b/include/pocketpy/interpreter/vm.h
index 71fcd083..d9d72683 100644
--- a/include/pocketpy/interpreter/vm.h
+++ b/include/pocketpy/interpreter/vm.h
@@ -48,7 +48,6 @@ typedef struct VM {
     py_TValue last_retval;
     py_TValue curr_exception;
     bool is_curr_exc_handled;  // handled by try-except block but not cleared yet
-    bool is_stopiteration;
 
     py_TValue reg[8];  // users' registers
 
diff --git a/include/pocketpy/pocketpy.h b/include/pocketpy/pocketpy.h
index a397cade..ffd1f943 100644
--- a/include/pocketpy/pocketpy.h
+++ b/include/pocketpy/pocketpy.h
@@ -295,6 +295,10 @@ PK_EXPORT void py_setdict(py_Ref self, py_Name name, py_Ref val);
 PK_EXPORT bool py_deldict(py_Ref self, py_Name name);
 /// Prepare an insertion to the object's `__dict__`.
 PK_EXPORT py_ItemRef py_emplacedict(py_Ref self, py_Name name);
+/// Apply a function to all items in the object's `__dict__`.
+/// Return `true` if the function is successful for all items.
+/// NOTE: Be careful if `f` modifies the object's `__dict__`.
+PK_EXPORT bool py_applydict(py_Ref self, bool (*f)(py_Name name, py_Ref val, void* ctx), void* ctx) PY_RAISE;
 
 /// Get the i-th slot of the object.
 /// The object must have slots and `i` must be in valid range.
diff --git a/python/_enum.py b/python/_enum.py
deleted file mode 100644
index c8879770..00000000
--- a/python/_enum.py
+++ /dev/null
@@ -1,11 +0,0 @@
-class Enum:
-    def __init__(self, name, value):
-        self.name = name
-        self.value = value
-
-    def __str__(self):
-        return f'{type(self).__name__}.{self.name}'
-    
-    def __repr__(self):
-        return f'<{str(self)}: {self.value!r}>'
-    
diff --git a/src/common/_generated.c b/src/common/_generated.c
index df85cc11..183f7690 100644
--- a/src/common/_generated.c
+++ b/src/common/_generated.c
@@ -1,7 +1,6 @@
 // generated by prebuild.py
 #include "pocketpy/common/_generated.h"
 #include <string.h>
-const char kPythonLibs__enum[] = "class Enum:\n    def __init__(self, name, value):\n        self.name = name\n        self.value = value\n\n    def __str__(self):\n        return f'{type(self).__name__}.{self.name}'\n    \n    def __repr__(self):\n        return f'<{str(self)}: {self.value!r}>'\n    \n";
 const char kPythonLibs_bisect[] = "\"\"\"Bisection algorithms.\"\"\"\n\ndef insort_right(a, x, lo=0, hi=None):\n    \"\"\"Insert item x in list a, and keep it sorted assuming a is sorted.\n\n    If x is already in a, insert it to the right of the rightmost x.\n\n    Optional args lo (default 0) and hi (default len(a)) bound the\n    slice of a to be searched.\n    \"\"\"\n\n    lo = bisect_right(a, x, lo, hi)\n    a.insert(lo, x)\n\ndef bisect_right(a, x, lo=0, hi=None):\n    \"\"\"Return the index where to insert item x in list a, assuming a is sorted.\n\n    The return value i is such that all e in a[:i] have e <= x, and all e in\n    a[i:] have e > x.  So if x already appears in the list, a.insert(x) will\n    insert just after the rightmost x already there.\n\n    Optional args lo (default 0) and hi (default len(a)) bound the\n    slice of a to be searched.\n    \"\"\"\n\n    if lo < 0:\n        raise ValueError('lo must be non-negative')\n    if hi is None:\n        hi = len(a)\n    while lo < hi:\n        mid = (lo+hi)//2\n        if x < a[mid]: hi = mid\n        else: lo = mid+1\n    return lo\n\ndef insort_left(a, x, lo=0, hi=None):\n    \"\"\"Insert item x in list a, and keep it sorted assuming a is sorted.\n\n    If x is already in a, insert it to the left of the leftmost x.\n\n    Optional args lo (default 0) and hi (default len(a)) bound the\n    slice of a to be searched.\n    \"\"\"\n\n    lo = bisect_left(a, x, lo, hi)\n    a.insert(lo, x)\n\n\ndef bisect_left(a, x, lo=0, hi=None):\n    \"\"\"Return the index where to insert item x in list a, assuming a is sorted.\n\n    The return value i is such that all e in a[:i] have e < x, and all e in\n    a[i:] have e >= x.  So if x already appears in the list, a.insert(x) will\n    insert just before the leftmost x already there.\n\n    Optional args lo (default 0) and hi (default len(a)) bound the\n    slice of a to be searched.\n    \"\"\"\n\n    if lo < 0:\n        raise ValueError('lo must be non-negative')\n    if hi is None:\n        hi = len(a)\n    while lo < hi:\n        mid = (lo+hi)//2\n        if a[mid] < x: lo = mid+1\n        else: hi = mid\n    return lo\n\n# Create aliases\nbisect = bisect_right\ninsort = insort_right\n";
 const char kPythonLibs_builtins[] = "from pkpy import next as __pkpy_next\n\ndef all(iterable):\n    for i in iterable:\n        if not i:\n            return False\n    return True\n\ndef any(iterable):\n    for i in iterable:\n        if i:\n            return True\n    return False\n\ndef enumerate(iterable, start=0):\n    n = start\n    for elem in iterable:\n        yield n, elem\n        n += 1\n\ndef sum(iterable):\n    res = 0\n    for i in iterable:\n        res += i\n    return res\n\ndef map(f, iterable):\n    for i in iterable:\n        yield f(i)\n\ndef filter(f, iterable):\n    for i in iterable:\n        if f(i):\n            yield i\n\ndef zip(a, b):\n    a = iter(a)\n    b = iter(b)\n    while True:\n        ai = __pkpy_next(a)\n        bi = __pkpy_next(b)\n        if ai is StopIteration or bi is StopIteration:\n            break\n        yield ai, bi\n\ndef reversed(iterable):\n    a = list(iterable)\n    a.reverse()\n    return a\n\ndef sorted(iterable, key=None, reverse=False):\n    a = list(iterable)\n    a.sort(key=key, reverse=reverse)\n    return a\n\n##### str #####\ndef __format_string(self: str, *args, **kwargs) -> str:\n    def tokenizeString(s: str):\n        tokens = []\n        L, R = 0,0\n        \n        mode = None\n        curArg = 0\n        # lookingForKword = False\n        \n        while(R<len(s)):\n            curChar = s[R]\n            nextChar = s[R+1] if R+1<len(s) else ''\n            \n            # Invalid case 1: stray '}' encountered, example: \"ABCD EFGH {name} IJKL}\", \"Hello {vv}}\", \"HELLO {0} WORLD}\"\n            if curChar == '}' and nextChar != '}':\n                raise ValueError(\"Single '}' encountered in format string\")        \n            \n            # Valid Case 1: Escaping case, we escape \"{{ or \"}}\" to be \"{\" or \"}\", example: \"{{}}\", \"{{My Name is {0}}}\"\n            if (curChar == '{' and nextChar == '{') or (curChar == '}' and nextChar == '}'):\n                \n                if (L<R): # Valid Case 1.1: make sure we are not adding empty string\n                    tokens.append(s[L:R]) # add the string before the escape\n                \n                \n                tokens.append(curChar) # Valid Case 1.2: add the escape char\n                L = R+2 # move the left pointer to the next char\n                R = R+2 # move the right pointer to the next char\n                continue\n            \n            # Valid Case 2: Regular command line arg case: example:  \"ABCD EFGH {} IJKL\", \"{}\", \"HELLO {} WORLD\"\n            elif curChar == '{' and nextChar == '}':\n                if mode is not None and mode != 'auto':\n                    # Invalid case 2: mixing automatic and manual field specifications -- example: \"ABCD EFGH {name} IJKL {}\", \"Hello {vv} {}\", \"HELLO {0} WORLD {}\" \n                    raise ValueError(\"Cannot switch from manual field numbering to automatic field specification\")\n                \n                mode = 'auto'\n                if(L<R): # Valid Case 2.1: make sure we are not adding empty string\n                    tokens.append(s[L:R]) # add the string before the special marker for the arg\n                \n                tokens.append(\"{\"+str(curArg)+\"}\") # Valid Case 2.2: add the special marker for the arg\n                curArg+=1 # increment the arg position, this will be used for referencing the arg later\n                \n                L = R+2 # move the left pointer to the next char\n                R = R+2 # move the right pointer to the next char\n                continue\n            \n            # Valid Case 3: Key-word arg case: example: \"ABCD EFGH {name} IJKL\", \"Hello {vv}\", \"HELLO {name} WORLD\"\n            elif (curChar == '{'):\n                \n                if mode is not None and mode != 'manual':\n                    # # Invalid case 2: mixing automatic and manual field specifications -- example: \"ABCD EFGH {} IJKL {name}\", \"Hello {} {1}\", \"HELLO {} WORLD {name}\"\n                    raise ValueError(\"Cannot switch from automatic field specification to manual field numbering\")\n                \n                mode = 'manual'\n                \n                if(L<R): # Valid case 3.1: make sure we are not adding empty string\n                    tokens.append(s[L:R]) # add the string before the special marker for the arg\n                \n                # We look for the end of the keyword          \n                kwL = R # Keyword left pointer\n                kwR = R+1 # Keyword right pointer\n                while(kwR<len(s) and s[kwR]!='}'):\n                    if s[kwR] == '{': # Invalid case 3: stray '{' encountered, example: \"ABCD EFGH {n{ame} IJKL {\", \"Hello {vv{}}\", \"HELLO {0} WOR{LD}\"\n                        raise ValueError(\"Unexpected '{' in field name\")\n                    kwR += 1\n                \n                # Valid case 3.2: We have successfully found the end of the keyword\n                if kwR<len(s) and s[kwR] == '}':\n                    tokens.append(s[kwL:kwR+1]) # add the special marker for the arg\n                    L = kwR+1\n                    R = kwR+1\n                    \n                # Invalid case 4: We didn't find the end of the keyword, throw error\n                else:\n                    raise ValueError(\"Expected '}' before end of string\")\n                continue\n            \n            R = R+1\n        \n        \n        # Valid case 4: We have reached the end of the string, add the remaining string to the tokens \n        if L<R:\n            tokens.append(s[L:R])\n                \n        # print(tokens)\n        return tokens\n\n    tokens = tokenizeString(self)\n    argMap = {}\n    for i, a in enumerate(args):\n        argMap[str(i)] = a\n    final_tokens = []\n    for t in tokens:\n        if t[0] == '{' and t[-1] == '}':\n            key = t[1:-1]\n            argMapVal = argMap.get(key, None)\n            kwargsVal = kwargs.get(key, None)\n                                    \n            if argMapVal is None and kwargsVal is None:\n                raise ValueError(\"No arg found for token: \"+t)\n            elif argMapVal is not None:\n                final_tokens.append(str(argMapVal))\n            else:\n                final_tokens.append(str(kwargsVal))\n        else:\n            final_tokens.append(t)\n    \n    return ''.join(final_tokens)\n\nstr.format = __format_string\ndel __format_string\n\n\ndef help(obj):\n    if hasattr(obj, '__func__'):\n        obj = obj.__func__\n    # print(obj.__signature__)\n    if obj.__doc__:\n        print(obj.__doc__)\n\ndef complex(real, imag=0):\n    import cmath\n    return cmath.complex(real, imag)\n\n\nclass set:\n    def __init__(self, iterable=None):\n        iterable = iterable or []\n        self._a = {}\n        self.update(iterable)\n\n    def add(self, elem):\n        self._a[elem] = None\n        \n    def discard(self, elem):\n        self._a.pop(elem, None)\n\n    def remove(self, elem):\n        del self._a[elem]\n        \n    def clear(self):\n        self._a.clear()\n\n    def update(self, other):\n        for elem in other:\n            self.add(elem)\n\n    def __len__(self):\n        return len(self._a)\n    \n    def copy(self):\n        return set(self._a.keys())\n    \n    def __and__(self, other):\n        return {elem for elem in self if elem in other}\n\n    def __sub__(self, other):\n        return {elem for elem in self if elem not in other}\n    \n    def __or__(self, other):\n        ret = self.copy()\n        ret.update(other)\n        return ret\n\n    def __xor__(self, other): \n        _0 = self - other\n        _1 = other - self\n        return _0 | _1\n\n    def union(self, other):\n        return self | other\n\n    def intersection(self, other):\n        return self & other\n\n    def difference(self, other):\n        return self - other\n\n    def symmetric_difference(self, other):      \n        return self ^ other\n    \n    def __eq__(self, other):\n        if not isinstance(other, set):\n            return NotImplemented\n        return len(self ^ other) == 0\n    \n    def __ne__(self, other):\n        if not isinstance(other, set):\n            return NotImplemented\n        return len(self ^ other) != 0\n\n    def isdisjoint(self, other):\n        return len(self & other) == 0\n    \n    def issubset(self, other):\n        return len(self - other) == 0\n    \n    def issuperset(self, other):\n        return len(other - self) == 0\n\n    def __contains__(self, elem):\n        return elem in self._a\n    \n    def __repr__(self):\n        if len(self) == 0:\n            return 'set()'\n        return '{'+ ', '.join([repr(i) for i in self._a.keys()]) + '}'\n    \n    def __iter__(self):\n        return iter(self._a.keys())";
 const char kPythonLibs_cmath[] = "import math\n\nclass complex:\n    def __init__(self, real, imag=0):\n        self._real = float(real)\n        self._imag = float(imag)\n\n    @property\n    def real(self):\n        return self._real\n    \n    @property\n    def imag(self):\n        return self._imag\n\n    def conjugate(self):\n        return complex(self.real, -self.imag)\n    \n    def __repr__(self):\n        s = ['(', str(self.real)]\n        s.append('-' if self.imag < 0 else '+')\n        s.append(str(abs(self.imag)))\n        s.append('j)')\n        return ''.join(s)\n    \n    def __eq__(self, other):\n        if type(other) is complex:\n            return self.real == other.real and self.imag == other.imag\n        if type(other) in (int, float):\n            return self.real == other and self.imag == 0\n        return NotImplemented\n    \n    def __ne__(self, other):\n        res = self == other\n        if res is NotImplemented:\n            return res\n        return not res\n    \n    def __add__(self, other):\n        if type(other) is complex:\n            return complex(self.real + other.real, self.imag + other.imag)\n        if type(other) in (int, float):\n            return complex(self.real + other, self.imag)\n        return NotImplemented\n        \n    def __radd__(self, other):\n        return self.__add__(other)\n    \n    def __sub__(self, other):\n        if type(other) is complex:\n            return complex(self.real - other.real, self.imag - other.imag)\n        if type(other) in (int, float):\n            return complex(self.real - other, self.imag)\n        return NotImplemented\n    \n    def __rsub__(self, other):\n        if type(other) is complex:\n            return complex(other.real - self.real, other.imag - self.imag)\n        if type(other) in (int, float):\n            return complex(other - self.real, -self.imag)\n        return NotImplemented\n    \n    def __mul__(self, other):\n        if type(other) is complex:\n            return complex(self.real * other.real - self.imag * other.imag,\n                           self.real * other.imag + self.imag * other.real)\n        if type(other) in (int, float):\n            return complex(self.real * other, self.imag * other)\n        return NotImplemented\n    \n    def __rmul__(self, other):\n        return self.__mul__(other)\n    \n    def __truediv__(self, other):\n        if type(other) is complex:\n            denominator = other.real ** 2 + other.imag ** 2\n            real_part = (self.real * other.real + self.imag * other.imag) / denominator\n            imag_part = (self.imag * other.real - self.real * other.imag) / denominator\n            return complex(real_part, imag_part)\n        if type(other) in (int, float):\n            return complex(self.real / other, self.imag / other)\n        return NotImplemented\n    \n    def __pow__(self, other: int | float):\n        if type(other) in (int, float):\n            return complex(self.__abs__() ** other * math.cos(other * phase(self)),\n                           self.__abs__() ** other * math.sin(other * phase(self)))\n        return NotImplemented\n    \n    def __abs__(self) -> float:\n        return math.sqrt(self.real ** 2 + self.imag ** 2)\n\n    def __neg__(self):\n        return complex(-self.real, -self.imag)\n    \n    def __hash__(self):\n        return hash((self.real, self.imag))\n\n\n# Conversions to and from polar coordinates\n\ndef phase(z: complex):\n    return math.atan2(z.imag, z.real)\n\ndef polar(z: complex):\n    return z.__abs__(), phase(z)\n\ndef rect(r: float, phi: float):\n    return r * math.cos(phi) + r * math.sin(phi) * 1j\n\n# Power and logarithmic functions\n\ndef exp(z: complex):\n    return math.exp(z.real) * rect(1, z.imag)\n\ndef log(z: complex, base=2.718281828459045):\n    return math.log(z.__abs__(), base) + phase(z) * 1j\n\ndef log10(z: complex):\n    return log(z, 10)\n\ndef sqrt(z: complex):\n    return z ** 0.5\n\n# Trigonometric functions\n\ndef acos(z: complex):\n    return -1j * log(z + sqrt(z * z - 1))\n\ndef asin(z: complex):\n    return -1j * log(1j * z + sqrt(1 - z * z))\n\ndef atan(z: complex):\n    return 1j / 2 * log((1 - 1j * z) / (1 + 1j * z))\n\ndef cos(z: complex):\n    return (exp(z) + exp(-z)) / 2\n\ndef sin(z: complex):\n    return (exp(z) - exp(-z)) / (2 * 1j)\n\ndef tan(z: complex):\n    return sin(z) / cos(z)\n\n# Hyperbolic functions\n\ndef acosh(z: complex):\n    return log(z + sqrt(z * z - 1))\n\ndef asinh(z: complex):\n    return log(z + sqrt(z * z + 1))\n\ndef atanh(z: complex):\n    return 1 / 2 * log((1 + z) / (1 - z))\n\ndef cosh(z: complex):\n    return (exp(z) + exp(-z)) / 2\n\ndef sinh(z: complex):\n    return (exp(z) - exp(-z)) / 2\n\ndef tanh(z: complex):\n    return sinh(z) / cosh(z)\n\n# Classification functions\n\ndef isfinite(z: complex):\n    return math.isfinite(z.real) and math.isfinite(z.imag)\n\ndef isinf(z: complex):\n    return math.isinf(z.real) or math.isinf(z.imag)\n\ndef isnan(z: complex):\n    return math.isnan(z.real) or math.isnan(z.imag)\n\ndef isclose(a: complex, b: complex):\n    return math.isclose(a.real, b.real) and math.isclose(a.imag, b.imag)\n\n# Constants\n\npi = math.pi\ne = math.e\ntau = 2 * pi\ninf = math.inf\ninfj = complex(0, inf)\nnan = math.nan\nnanj = complex(0, nan)\n";
diff --git a/src/interpreter/vm.c b/src/interpreter/vm.c
index 7f9ff205..3bce47c4 100644
--- a/src/interpreter/vm.c
+++ b/src/interpreter/vm.c
@@ -68,7 +68,6 @@ void VM__ctor(VM* self) {
     self->last_retval = *py_NIL;
     self->curr_exception = *py_NIL;
     self->is_curr_exc_handled = false;
-    self->is_stopiteration = false;
 
     self->__curr_class = NULL;
 
@@ -206,6 +205,7 @@ void VM__ctor(VM* self) {
     pk__add_module_time();
     pk__add_module_easing();
     pk__add_module_traceback();
+    pk__add_module_enum();
 
     // add python builtins
     do {
diff --git a/src/modules/enum.c b/src/modules/enum.c
new file mode 100644
index 00000000..ac1f5630
--- /dev/null
+++ b/src/modules/enum.c
@@ -0,0 +1,91 @@
+#include "pocketpy/pocketpy.h"
+#include "pocketpy/interpreter/vm.h"
+#include "pocketpy/common/sstream.h"
+
+static bool Enum__wrapper_field(py_Name name, py_Ref value, void* ctx) {
+    c11_sv name_sv = py_name2sv(name);
+    if(name_sv.size == 0 || name_sv.data[0] == '_') return true;
+    py_push(ctx);
+    py_pushnil();
+    py_newstr(py_pushtmp(), py_name2str(name));
+    py_push(value);
+    bool ok = py_vectorcall(2, 0);
+    if(!ok) return false;
+    py_assign(value, py_retval());
+    return true;
+}
+
+static void Enum__on_end_subclass(py_TypeInfo* derived_ti) {
+    derived_ti->is_sealed = true;
+    py_applydict(&derived_ti->self, Enum__wrapper_field, &derived_ti->self);
+}
+
+static bool Enum__new__(int argc, py_Ref argv) {
+    py_newobject(py_retval(), py_totype(argv), 2, 0);
+    return true;
+}
+
+static bool Enum__init__(int argc, py_Ref argv) {
+    PY_CHECK_ARGC(3);
+    PY_CHECK_ARG_TYPE(1, tp_str);
+    py_setslot(argv, 0, py_arg(1));
+    py_setslot(argv, 1, py_arg(2));
+    py_newnone(py_retval());
+    return true;
+}
+
+static bool Enum__str__(int argc, py_Ref argv) {
+    PY_CHECK_ARGC(1);
+    // f'{type(self).__name__}.{self.name}'
+    c11_sbuf buf;
+    c11_sbuf__ctor(&buf);
+    c11_sbuf__write_cstr(&buf, py_tpname(argv->type));
+    c11_sbuf__write_char(&buf, '.');
+    c11_sbuf__write_cstr(&buf, py_tostr(py_getslot(argv, 0)));
+    c11_sbuf__py_submit(&buf, py_retval());
+    return true;
+}
+
+static bool Enum__repr__(int argc, py_Ref argv) {
+    PY_CHECK_ARGC(1);
+    // f'<{str(self)}: {self.value!r}>'
+    if(!py_str(argv)) return false;
+    py_push(py_retval());  // str(self)
+    if(!py_repr(py_getslot(argv, 1))) return false;
+    py_push(py_retval());  // repr(self.value)
+    c11_sbuf buf;
+    c11_sbuf__ctor(&buf);
+    c11_sbuf__write_cstr(&buf, "<");
+    c11_sbuf__write_cstr(&buf, py_tostr(py_peek(-2)));
+    c11_sbuf__write_cstr(&buf, ": ");
+    c11_sbuf__write_cstr(&buf, py_tostr(py_peek(-1)));
+    c11_sbuf__write_cstr(&buf, ">");
+    c11_sbuf__py_submit(&buf, py_retval());
+    py_shrink(2);
+    return true;
+}
+
+static bool Enum__name(int argc, py_Ref argv) {
+    py_assign(py_retval(), py_getslot(argv, 0));
+    return true;
+}
+
+static bool Enum__value(int argc, py_Ref argv) {
+    py_assign(py_retval(), py_getslot(argv, 1));
+    return true;
+}
+
+void pk__add_module_enum() {
+    py_Ref mod = py_newmodule("enum");
+    py_Type type = py_newtype("Enum", tp_object, mod, NULL);
+
+    py_bindmagic(type, __new__, Enum__new__);
+    py_bindmagic(type, __init__, Enum__init__);
+    py_bindmagic(type, __str__, Enum__str__);
+    py_bindmagic(type, __repr__, Enum__repr__);
+    py_bindproperty(type, "name", Enum__name, NULL);
+    py_bindproperty(type, "value", Enum__value, NULL);
+
+    py_TypeInfo* ti = c11__at(py_TypeInfo, &pk_current_vm->types, type);
+    ti->on_end_subclass = Enum__on_end_subclass;
+}
\ No newline at end of file
diff --git a/src/public/internal.c b/src/public/internal.c
index 2fac191f..e2b9bbcd 100644
--- a/src/public/internal.c
+++ b/src/public/internal.c
@@ -105,7 +105,12 @@ bool py_callcfunc(py_CFunction f, int argc, py_Ref argv) {
     py_StackRef p0 = py_peek(0);
     py_newnil(py_retval());
     bool ok = f(argc, argv);
-    if(!ok) return false;
+    if(!ok) {
+        if(!py_checkexc(true)) {
+            c11__abort("py_CFunction returns `false` but no exception is set!");
+        }
+        return false;
+    }
     if(py_peek(0) != p0) {
         c11__abort("py_CFunction corrupts the stack! Did you forget to call `py_pop()`?");
     }
@@ -219,9 +224,4 @@ bool pk_callmagic(py_Name name, int argc, py_Ref argv) {
     return py_call(tmp, argc, argv);
 }
 
-bool StopIteration() {
-    VM* vm = pk_current_vm;
-    assert(!vm->is_stopiteration);  // flag is already set
-    vm->is_stopiteration = true;
-    return false;
-}
\ No newline at end of file
+bool StopIteration() { return py_exception(tp_StopIteration, ""); }
\ No newline at end of file
diff --git a/src/public/py_exception.c b/src/public/py_exception.c
index d298f61a..70c3a8ca 100644
--- a/src/public/py_exception.c
+++ b/src/public/py_exception.c
@@ -152,7 +152,6 @@ void py_clearexc(py_StackRef p0) {
     vm->last_retval = *py_NIL;
     vm->curr_exception = *py_NIL;
     vm->is_curr_exc_handled = false;
-    vm->is_stopiteration = false;
     vm->__curr_class = NULL;
     if(p0) vm->stack.sp = p0;
 }
diff --git a/src/public/py_ops.c b/src/public/py_ops.c
index 99d17cf3..ccb86686 100644
--- a/src/public/py_ops.c
+++ b/src/public/py_ops.c
@@ -70,20 +70,17 @@ bool py_iter(py_Ref val) {
 
 int py_next(py_Ref val) {
     VM* vm = pk_current_vm;
-    vm->is_stopiteration = false;
     py_Ref tmp = py_tpfindmagic(val->type, __next__);
     if(!tmp) {
         TypeError("'%t' object is not an iterator", val->type);
         return -1;
     }
-    if(py_call(tmp, 1, val)) return true;
+    if(py_call(tmp, 1, val)) return 1;
     if(vm->curr_exception.type == tp_StopIteration) {
         py_clearexc(NULL);
-        vm->is_stopiteration = true;
+        return 0;
     }
-    int retval = vm->is_stopiteration ? 0 : -1;
-    vm->is_stopiteration = false;
-    return retval;
+    return -1;
 }
 
 bool py_getattr(py_Ref self, py_Name name) {
diff --git a/src/public/stack_ops.c b/src/public/stack_ops.c
index ea257647..c7f79a4b 100644
--- a/src/public/stack_ops.c
+++ b/src/public/stack_ops.c
@@ -34,6 +34,17 @@ py_ItemRef py_emplacedict(py_Ref self, py_Name name){
     return py_getdict(self, name);
 }
 
+bool py_applydict(py_Ref self, bool (*f)(py_Name, py_Ref, void *), void *ctx){
+    assert(self && self->is_ptr);
+    NameDict* dict = PyObject__dict(self->_obj);
+    for(int i = 0; i < dict->length; i++){
+        NameDict_KV* kv = c11__at(NameDict_KV, dict, i);
+        bool ok = f(kv->key, &kv->value, ctx);
+        if(!ok) return false;
+    }
+    return true;
+}
+
 bool py_deldict(py_Ref self, py_Name name) {
     assert(self && self->is_ptr);
     if(!py_ismagicname(name) || self->type != tp_type) {
diff --git a/tests/90_enum.py b/tests/82_enum.py
similarity index 98%
rename from tests/90_enum.py
rename to tests/82_enum.py
index d9a197a7..4844c531 100644
--- a/tests/90_enum.py
+++ b/tests/82_enum.py
@@ -1,5 +1,3 @@
-exit()
-
 from enum import Enum
 
 class A(Enum):