diff --git a/include/pocketpy/common/str.hpp b/include/pocketpy/common/str.hpp
index 2ab20865..ff7547f6 100644
--- a/include/pocketpy/common/str.hpp
+++ b/include/pocketpy/common/str.hpp
@@ -256,7 +256,7 @@ struct StrName {
 
     StrName() : index(0) {}
 
-    explicit StrName(uint16_t index) : index(index) {}
+    StrName(uint16_t index) : index(index) {}
 
     StrName(const char* s) : index(get(s).index) {}
 
@@ -275,18 +275,16 @@ struct StrName {
     bool operator> (const StrName& other) const noexcept { return sv() > other.sv(); }
 
     inline static StrName get(std::string_view s){
-        uint16_t index = pkpy_StrName__map({s.data(), (int)s.size()});
+        uint16_t index = pkpy_StrName__map2({s.data(), (int)s.size()});
         return StrName(index);
     }
 
     std::string_view sv() const{
-        c11_string s = pkpy_StrName__rmap(index);
-        return std::string_view(s.data, s.size);
+        return pkpy_StrName__rmap(index);
     }
 
     const char* c_str() const{
-        c11_string s = pkpy_StrName__rmap(index);
-        return s.data;
+        return pkpy_StrName__rmap(index);
     }
 };
 
@@ -401,63 +399,6 @@ struct CString {
     operator const char* () const { return ptr; }
 };
 
-// unary operators
-extern const StrName __repr__;
-extern const StrName __str__;
-extern const StrName __hash__;
-extern const StrName __len__;
-extern const StrName __iter__;
-extern const StrName __next__;
-extern const StrName __neg__;
-// logical operators
-extern const StrName __eq__;
-extern const StrName __lt__;
-extern const StrName __le__;
-extern const StrName __gt__;
-extern const StrName __ge__;
-extern const StrName __contains__;
-// binary operators
-extern const StrName __add__;
-extern const StrName __radd__;
-extern const StrName __sub__;
-extern const StrName __rsub__;
-extern const StrName __mul__;
-extern const StrName __rmul__;
-extern const StrName __truediv__;
-extern const StrName __floordiv__;
-extern const StrName __mod__;
-extern const StrName __pow__;
-extern const StrName __matmul__;
-extern const StrName __lshift__;
-extern const StrName __rshift__;
-extern const StrName __and__;
-extern const StrName __or__;
-extern const StrName __xor__;
-extern const StrName __invert__;
-// indexer
-extern const StrName __getitem__;
-extern const StrName __setitem__;
-extern const StrName __delitem__;
-
-// specials
-extern const StrName __new__;
-extern const StrName __init__;
-extern const StrName __call__;
-extern const StrName __divmod__;
-extern const StrName __enter__;
-extern const StrName __exit__;
-extern const StrName __name__;
-extern const StrName __all__;
-extern const StrName __package__;
-extern const StrName __path__;
-extern const StrName __class__;
-extern const StrName __missing__;
-
-extern const StrName pk_id_add;
-extern const StrName pk_id_set;
-extern const StrName pk_id_long;
-extern const StrName pk_id_complex;
-
 #define DEF_SNAME(name) const static StrName name(#name)
 
 }  // namespace pkpy
diff --git a/include/pocketpy/common/strname.h b/include/pocketpy/common/strname.h
index aa473c8c..da375328 100644
--- a/include/pocketpy/common/strname.h
+++ b/include/pocketpy/common/strname.h
@@ -7,12 +7,71 @@
 extern "C" {
 #endif
 
-uint16_t pkpy_StrName__map(c11_string name);
-c11_string pkpy_StrName__rmap(uint16_t index);
+uint16_t pkpy_StrName__map(const char*);
+uint16_t pkpy_StrName__map2(c11_string);
+const char* pkpy_StrName__rmap(uint16_t index);
 
 void pkpy_StrName__initialize();
 void pkpy_StrName__finalize();
 
+
+// unary operators
+extern uint16_t __repr__;
+extern uint16_t __str__;
+extern uint16_t __hash__;
+extern uint16_t __len__;
+extern uint16_t __iter__;
+extern uint16_t __next__;
+extern uint16_t __neg__;
+// logical operators
+extern uint16_t __eq__;
+extern uint16_t __lt__;
+extern uint16_t __le__;
+extern uint16_t __gt__;
+extern uint16_t __ge__;
+extern uint16_t __contains__;
+// binary operators
+extern uint16_t __add__;
+extern uint16_t __radd__;
+extern uint16_t __sub__;
+extern uint16_t __rsub__;
+extern uint16_t __mul__;
+extern uint16_t __rmul__;
+extern uint16_t __truediv__;
+extern uint16_t __floordiv__;
+extern uint16_t __mod__;
+extern uint16_t __pow__;
+extern uint16_t __matmul__;
+extern uint16_t __lshift__;
+extern uint16_t __rshift__;
+extern uint16_t __and__;
+extern uint16_t __or__;
+extern uint16_t __xor__;
+extern uint16_t __invert__;
+// indexer
+extern uint16_t __getitem__;
+extern uint16_t __setitem__;
+extern uint16_t __delitem__;
+
+// specials
+extern uint16_t __new__;
+extern uint16_t __init__;
+extern uint16_t __call__;
+extern uint16_t __divmod__;
+extern uint16_t __enter__;
+extern uint16_t __exit__;
+extern uint16_t __name__;
+extern uint16_t __all__;
+extern uint16_t __package__;
+extern uint16_t __path__;
+extern uint16_t __class__;
+extern uint16_t __missing__;
+
+extern uint16_t pk_id_add;
+extern uint16_t pk_id_set;
+extern uint16_t pk_id_long;
+extern uint16_t pk_id_complex;
+
 #ifdef __cplusplus
 }
 #endif
\ No newline at end of file
diff --git a/src/common/str.cpp b/src/common/str.cpp
deleted file mode 100644
index 51cdcdc9..00000000
--- a/src/common/str.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-#include "pocketpy/common/str.hpp"
-
-#include <cassert>
-#include <ostream>
-#include <algorithm>
-#include <cmath>
-#include <map>
-
-namespace pkpy {
-
-// unary operators
-const StrName __repr__ = StrName::get("__repr__");
-const StrName __str__ = StrName::get("__str__");
-const StrName __hash__ = StrName::get("__hash__");
-const StrName __len__ = StrName::get("__len__");
-const StrName __iter__ = StrName::get("__iter__");
-const StrName __next__ = StrName::get("__next__");
-const StrName __neg__ = StrName::get("__neg__");
-// logical operators
-const StrName __eq__ = StrName::get("__eq__");
-const StrName __lt__ = StrName::get("__lt__");
-const StrName __le__ = StrName::get("__le__");
-const StrName __gt__ = StrName::get("__gt__");
-const StrName __ge__ = StrName::get("__ge__");
-const StrName __contains__ = StrName::get("__contains__");
-// binary operators
-const StrName __add__ = StrName::get("__add__");
-const StrName __radd__ = StrName::get("__radd__");
-const StrName __sub__ = StrName::get("__sub__");
-const StrName __rsub__ = StrName::get("__rsub__");
-const StrName __mul__ = StrName::get("__mul__");
-const StrName __rmul__ = StrName::get("__rmul__");
-const StrName __truediv__ = StrName::get("__truediv__");
-const StrName __floordiv__ = StrName::get("__floordiv__");
-const StrName __mod__ = StrName::get("__mod__");
-const StrName __pow__ = StrName::get("__pow__");
-const StrName __matmul__ = StrName::get("__matmul__");
-const StrName __lshift__ = StrName::get("__lshift__");
-const StrName __rshift__ = StrName::get("__rshift__");
-const StrName __and__ = StrName::get("__and__");
-const StrName __or__ = StrName::get("__or__");
-const StrName __xor__ = StrName::get("__xor__");
-const StrName __invert__ = StrName::get("__invert__");
-// indexer
-const StrName __getitem__ = StrName::get("__getitem__");
-const StrName __setitem__ = StrName::get("__setitem__");
-const StrName __delitem__ = StrName::get("__delitem__");
-
-// specials
-const StrName __new__ = StrName::get("__new__");
-const StrName __init__ = StrName::get("__init__");
-const StrName __call__ = StrName::get("__call__");
-const StrName __divmod__ = StrName::get("__divmod__");
-const StrName __enter__ = StrName::get("__enter__");
-const StrName __exit__ = StrName::get("__exit__");
-const StrName __name__ = StrName::get("__name__");
-const StrName __all__ = StrName::get("__all__");
-const StrName __package__ = StrName::get("__package__");
-const StrName __path__ = StrName::get("__path__");
-const StrName __class__ = StrName::get("__class__");
-const StrName __missing__ = StrName::get("__missing__");
-
-const StrName pk_id_add = StrName::get("add");
-const StrName pk_id_set = StrName::get("set");
-const StrName pk_id_long = StrName::get("long");
-const StrName pk_id_complex = StrName::get("complex");
-
-}  // namespace pkpy
diff --git a/src/common/strname.c b/src/common/strname.c
index a629bd0c..892e4760 100644
--- a/src/common/strname.c
+++ b/src/common/strname.c
@@ -18,6 +18,63 @@ void pkpy_StrName__initialize(){
     }
     c11_vector__ctor(&_r_interned, sizeof(c11_string));
     _initialized = true;
+
+    // unary operators
+    __repr__ = pkpy_StrName__map("__repr__");
+    __str__ = pkpy_StrName__map("__str__");
+    __hash__ = pkpy_StrName__map("__hash__");
+    __len__ = pkpy_StrName__map("__len__");
+    __iter__ = pkpy_StrName__map("__iter__");
+    __next__ = pkpy_StrName__map("__next__");
+    __neg__ = pkpy_StrName__map("__neg__");
+    // logical operators
+    __eq__ = pkpy_StrName__map("__eq__");
+    __lt__ = pkpy_StrName__map("__lt__");
+    __le__ = pkpy_StrName__map("__le__");
+    __gt__ = pkpy_StrName__map("__gt__");
+    __ge__ = pkpy_StrName__map("__ge__");
+    __contains__ = pkpy_StrName__map("__contains__");
+    // binary operators
+    __add__ = pkpy_StrName__map("__add__");
+    __radd__ = pkpy_StrName__map("__radd__");
+    __sub__ = pkpy_StrName__map("__sub__");
+    __rsub__ = pkpy_StrName__map("__rsub__");
+    __mul__ = pkpy_StrName__map("__mul__");
+    __rmul__ = pkpy_StrName__map("__rmul__");
+    __truediv__ = pkpy_StrName__map("__truediv__");
+    __floordiv__ = pkpy_StrName__map("__floordiv__");
+    __mod__ = pkpy_StrName__map("__mod__");
+    __pow__ = pkpy_StrName__map("__pow__");
+    __matmul__ = pkpy_StrName__map("__matmul__");
+    __lshift__ = pkpy_StrName__map("__lshift__");
+    __rshift__ = pkpy_StrName__map("__rshift__");
+    __and__ = pkpy_StrName__map("__and__");
+    __or__ = pkpy_StrName__map("__or__");
+    __xor__ = pkpy_StrName__map("__xor__");
+    __invert__ = pkpy_StrName__map("__invert__");
+    // indexer
+    __getitem__ = pkpy_StrName__map("__getitem__");
+    __setitem__ = pkpy_StrName__map("__setitem__");
+    __delitem__ = pkpy_StrName__map("__delitem__");
+
+    // specials
+    __new__ = pkpy_StrName__map("__new__");
+    __init__ = pkpy_StrName__map("__init__");
+    __call__ = pkpy_StrName__map("__call__");
+    __divmod__ = pkpy_StrName__map("__divmod__");
+    __enter__ = pkpy_StrName__map("__enter__");
+    __exit__ = pkpy_StrName__map("__exit__");
+    __name__ = pkpy_StrName__map("__name__");
+    __all__ = pkpy_StrName__map("__all__");
+    __package__ = pkpy_StrName__map("__package__");
+    __path__ = pkpy_StrName__map("__path__");
+    __class__ = pkpy_StrName__map("__class__");
+    __missing__ = pkpy_StrName__map("__missing__");
+
+    pk_id_add = pkpy_StrName__map("add");
+    pk_id_set = pkpy_StrName__map("set");
+    pk_id_long = pkpy_StrName__map("long");
+    pk_id_complex = pkpy_StrName__map("complex");
 }
 
 void pkpy_StrName__finalize(){
@@ -26,7 +83,11 @@ void pkpy_StrName__finalize(){
     c11_vector__dtor(&_r_interned);
 }
 
-uint16_t pkpy_StrName__map(c11_string name){
+uint16_t pkpy_StrName__map(const char* name){
+    return pkpy_StrName__map2((c11_string){name, strlen(name)});
+}
+
+uint16_t pkpy_StrName__map2(c11_string name){
     // TODO: PK_GLOBAL_SCOPE_LOCK()
     if(!_initialized){
         pkpy_StrName__initialize(); // lazy init
@@ -49,9 +110,67 @@ uint16_t pkpy_StrName__map(c11_string name){
     return index;
 }
 
-c11_string pkpy_StrName__rmap(uint16_t index){
+const char* pkpy_StrName__rmap(uint16_t index){
     assert(_initialized);
     assert(index > 0 && index <= _interned.count);
-    char* p = c11__getitem(char*, &_r_interned, index - 1);
-    return (c11_string){p, strlen(p)};
+    return c11__getitem(char*, &_r_interned, index - 1);
 }
+
+
+
+// unary operators
+uint16_t __repr__;
+uint16_t __str__;
+uint16_t __hash__;
+uint16_t __len__;
+uint16_t __iter__;
+uint16_t __next__;
+uint16_t __neg__;
+// logical operators
+uint16_t __eq__;
+uint16_t __lt__;
+uint16_t __le__;
+uint16_t __gt__;
+uint16_t __ge__;
+uint16_t __contains__;
+// binary operators
+uint16_t __add__;
+uint16_t __radd__;
+uint16_t __sub__;
+uint16_t __rsub__;
+uint16_t __mul__;
+uint16_t __rmul__;
+uint16_t __truediv__;
+uint16_t __floordiv__;
+uint16_t __mod__;
+uint16_t __pow__;
+uint16_t __matmul__;
+uint16_t __lshift__;
+uint16_t __rshift__;
+uint16_t __and__;
+uint16_t __or__;
+uint16_t __xor__;
+uint16_t __invert__;
+// indexer
+uint16_t __getitem__;
+uint16_t __setitem__;
+uint16_t __delitem__;
+
+// specials
+uint16_t __new__;
+uint16_t __init__;
+uint16_t __call__;
+uint16_t __divmod__;
+uint16_t __enter__;
+uint16_t __exit__;
+uint16_t __name__;
+uint16_t __all__;
+uint16_t __package__;
+uint16_t __path__;
+uint16_t __class__;
+uint16_t __missing__;
+
+uint16_t pk_id_add;
+uint16_t pk_id_set;
+uint16_t pk_id_long;
+uint16_t pk_id_complex;