...

src/common.h

@@ -112,7 +112,7 @@ struct Type {
 
 #define PK_LAMBDA(x) ([](VM* vm, ArgsView args) { return x; })
 #define PK_VAR_LAMBDA(x) ([](VM* vm, ArgsView args) { return VAR(x); })
-#define PK_NONE_LAMBDA(x) ([](VM* vm, ArgsView args) { x; return vm->None; })
+#define PK_ACTION(x) ([](VM* vm, ArgsView args) { x; return vm->None; })
 
 #ifdef POCKETPY_H
 #define FATAL_ERROR() throw std::runtime_error( "L" + std::to_string(__LINE__) + " FATAL_ERROR()!");

src/obj.h

@@ -30,6 +30,8 @@ struct NativeFunc {
     UserData _userdata;
     bool _has_userdata;
 
+    const char* signature;
+
     template <typename T>
     void set_userdata(T data) {
         static_assert(std::is_trivially_copyable_v<T>);
@@ -49,8 +51,9 @@ struct NativeFunc {
         return reinterpret_cast<const T&>(_userdata);
     }
     
-    NativeFunc(NativeFuncC f, int argc, bool method){
+    NativeFunc(NativeFuncC f, int argc, bool method, const char* sig=nullptr){
         this->f = f;
+        this->signature = sig;
         this->argc = argc;
         if(argc != -1) this->argc += (int)method;
         _lua_f = nullptr;
@@ -300,6 +303,8 @@ __T _py_cast(VM* vm, PyObject* obj) {
 
 #define CAST_F(x) vm->num_to_float(x)
 
+#define CAST_DEFAULT(T, i, default_value) (i < args.size()) ? py_cast<T>(vm, args[index]) : (default_value)
+
 /*****************************************************************/
 template<>
 struct Py_<List> final: PyObject {

src/str.h

@@ -426,6 +426,13 @@ struct FastStrStream{
     }
 };
 
+struct CString{
+	const char* ptr;
+	CString(const char* ptr): ptr(ptr) {}
+	CString(const Str& str): ptr(str.c_str_temp()) {}
+    operator const char*() const { return ptr; }
+};
+
 // unary operators
 const StrName __repr__ = StrName::get("__repr__");
 const StrName __str__ = StrName::get("__str__");

src/vm.h

@@ -461,19 +461,19 @@ public:
     }
 
     template<int ARGC>
-    PyObject* bind_func(Str type, Str name, NativeFuncC fn) {
-        return bind_func<ARGC>(_find_type_object(type), name, fn);
+    PyObject* bind_func(Str type, Str name, NativeFuncC fn, const char* sig=nullptr) {
+        return bind_func<ARGC>(_find_type_object(type), name, fn, sig);
     }
 
     template<int ARGC>
-    PyObject* bind_method(Str type, Str name, NativeFuncC fn) {
-        return bind_method<ARGC>(_find_type_object(type), name, fn);
+    PyObject* bind_method(Str type, Str name, NativeFuncC fn, const char* sig=nullptr) {
+        return bind_method<ARGC>(_find_type_object(type), name, fn, sig);
     }
 
     template<int ARGC, typename __T>
-    PyObject* bind_constructor(__T&& type, NativeFuncC fn) {
+    PyObject* bind_constructor(__T&& type, NativeFuncC fn, const char* sig=nullptr) {
         static_assert(ARGC==-1 || ARGC>=1);
-        return bind_func<ARGC>(std::forward<__T>(type), "__new__", fn);
+        return bind_func<ARGC>(std::forward<__T>(type), "__new__", fn, sig);
     }
 
     template<typename T, typename __T>
@@ -494,8 +494,8 @@ public:
     }
 
     template<int ARGC>
-    PyObject* bind_builtin_func(Str name, NativeFuncC fn) {
-        return bind_func<ARGC>(builtins, name, fn);
+    PyObject* bind_builtin_func(Str name, NativeFuncC fn, const char* sig=nullptr) {
+        return bind_func<ARGC>(builtins, name, fn, sig);
     }
 
     int normalized_index(int index, int size){
@@ -545,6 +545,11 @@ public:
         TypeError("expected " + OBJ_NAME(_t(type)).escape() + ", got " + OBJ_NAME(_t(obj)).escape());
     }
 
+    void check_args_size(int size, int min_size, int max_size){
+        if(size >= min_size && size <= max_size) return;
+        TypeError(fmt("expected ", min_size, "-", max_size, " arguments, got ", size));
+    }
+
     void check_non_tagged_type(PyObject* obj, Type type){
         if(is_non_tagged_type(obj, type)) return;
         TypeError("expected " + OBJ_NAME(_t(type)).escape() + ", got " + OBJ_NAME(_t(obj)).escape());
@@ -676,9 +681,9 @@ public:
     PyObject* format(Str, PyObject*);
     void setattr(PyObject* obj, StrName name, PyObject* value);
     template<int ARGC>
-    PyObject* bind_method(PyObject*, Str, NativeFuncC);
+    PyObject* bind_method(PyObject*, Str, NativeFuncC, const char* sig=nullptr);
     template<int ARGC>
-    PyObject* bind_func(PyObject*, Str, NativeFuncC);
+    PyObject* bind_func(PyObject*, Str, NativeFuncC, const char* sig=nullptr);
     void _error(Exception);
     PyObject* _run_top_frame();
     void post_init();
@@ -813,6 +818,15 @@ template<> inline bool _py_cast<bool>(VM* vm, PyObject* obj){
     return obj == vm->True;
 }
 
+template<> inline CString py_cast<CString>(VM* vm, PyObject* obj){
+    vm->check_non_tagged_type(obj, vm->tp_str);
+    return PK_OBJ_GET(Str, obj).c_str_temp();
+}
+
+template<> inline CString _py_cast<CString>(VM* vm, PyObject* obj){
+    return PK_OBJ_GET(Str, obj).c_str_temp();
+}
+
 inline PyObject* py_var(VM* vm, const char val[]){
     return VAR(Str(val));
 }
@@ -1505,16 +1519,16 @@ inline void VM::setattr(PyObject* obj, StrName name, PyObject* value){
 }
 
 template<int ARGC>
-PyObject* VM::bind_method(PyObject* obj, Str name, NativeFuncC fn) {
+PyObject* VM::bind_method(PyObject* obj, Str name, NativeFuncC fn, const char* sig) {
     check_non_tagged_type(obj, tp_type);
-    PyObject* nf = VAR(NativeFunc(fn, ARGC, true));
+    PyObject* nf = VAR(NativeFunc(fn, ARGC, true, sig));
     obj->attr().set(name, nf);
     return nf;
 }
 
 template<int ARGC>
-PyObject* VM::bind_func(PyObject* obj, Str name, NativeFuncC fn) {
-    PyObject* nf = VAR(NativeFunc(fn, ARGC, false));
+PyObject* VM::bind_func(PyObject* obj, Str name, NativeFuncC fn, const char* sig) {
+    PyObject* nf = VAR(NativeFunc(fn, ARGC, false, sig));
     obj->attr().set(name, nf);
     return nf;
 }