# Functions

/// Initialize pocketpy and the default VM.
PK_API void py_initialize();

/// Finalize pocketpy and free all VMs.
PK_API void py_finalize();

/// Get the current VM index.
PK_API int py_currentvm();

/// Switch to a VM.
/// @param index index of the VM ranging from 0 to 16 (exclusive). `0` is the default VM.
PK_API void py_switchvm(int index);

/// Reset the current VM.
PK_API void py_resetvm();

/// Get the current VM context. This is used for user-defined data.
PK_API void* py_getvmctx();

/// Set the current VM context. This is used for user-defined data.
PK_API void py_setvmctx(void* ctx);

/// Set `sys.argv`. Used for storing command-line arguments.
PK_API void py_sys_setargv(int argc, char** argv);

/// Setup the callbacks for the current VM.
PK_API py_Callbacks* py_callbacks();

/// Run a source string.
/// @param source source string.
/// @param filename filename (for error messages).
/// @param mode compile mode. Use `EXEC_MODE` for statements `EVAL_MODE` for expressions.
/// @param module target module. Use NULL for the main module.
/// @return `true` if the execution is successful or `false` if an exception is raised.
PK_API bool py_exec(const char* source,
                       const char* filename,
                       enum py_CompileMode mode,
                       py_Ref module);

/// Evaluate a source string. Equivalent to `py_exec(source, "<string>", EVAL_MODE, module)`.
PK_API bool py_eval(const char* source, py_Ref module);

/// Run a source string with smart interpretation.
/// Example:
/// `py_newstr(py_r0(), "abc");`
/// `py_newint(py_r1(), 123);`
/// `py_smartexec("print(_0, _1)", NULL, py_r0(), py_r1());`
/// `// "abc 123" will be printed`.
PK_API bool py_smartexec(const char* source, py_Ref module, ...);

/// Evaluate a source string with smart interpretation.
/// Example:
/// `py_newstr(py_r0(), "abc");`
/// `py_smarteval("len(_)", NULL, py_r0());`
/// `int res = py_toint(py_retval());`
/// `// res will be 3`.
PK_API bool py_smarteval(const char* source, py_Ref module, ...);

/// Compile a source string into a code object.
/// Use python's `exec()` or `eval()` to execute it.
PK_API bool py_compile(const char* source,
                          const char* filename,
                          enum py_CompileMode mode,
                          bool is_dynamic);

/// Python equivalent to `globals()`.
PK_API void py_newglobals(py_OutRef);

/// Python equivalent to `locals()`.
/// @return a temporary object, which expires on the associated function return.
PK_API void py_newlocals(py_OutRef);

/// A shorthand for `True`.
PK_API py_GlobalRef py_True();

/// A shorthand for `False`.
PK_API py_GlobalRef py_False();

/// A shorthand for `None`.
PK_API py_GlobalRef py_None();

/// A shorthand for `nil`. `nil` is not a valid python object.
PK_API py_GlobalRef py_NIL();

/// Create an `int` object.
PK_API void py_newint(py_OutRef, py_i64);

/// Create a `float` object.
PK_API void py_newfloat(py_OutRef, py_f64);

/// Create a `bool` object.
PK_API void py_newbool(py_OutRef, bool);

/// Create a `str` object from a null-terminated string (utf-8).
PK_API void py_newstr(py_OutRef, const char*);

/// Create a `str` object with `n` UNINITIALIZED bytes plus `'\0'`.
PK_API char* py_newstrn(py_OutRef, int);

/// Create a `str` object from a `c11_sv`.
PK_API void py_newstrv(py_OutRef, c11_sv);

/// Create a `None` object.
PK_API void py_newnone(py_OutRef);

/// Create a `NotImplemented` object.
PK_API void py_newnotimplemented(py_OutRef);

/// Create a `...` object.
PK_API void py_newellipsis(py_OutRef);

/// Create a `nil` object. `nil` is an invalid representation of an object.
/// Don't use it unless you know what you are doing.
PK_API void py_newnil(py_OutRef);

/// Create a `tuple` with `n` UNINITIALIZED elements.
/// You should initialize all elements before using it.
PK_API void py_newtuple(py_OutRef, int n);

/// Create an empty `list`.
PK_API void py_newlist(py_OutRef);

/// Create a `list` with `n` UNINITIALIZED elements.
/// You should initialize all elements before using it.
PK_API void py_newlistn(py_OutRef, int n);

/// Create an empty `dict`.
PK_API void py_newdict(py_OutRef);

/// Create an UNINITIALIZED `slice` object.
/// You should use `py_setslot()` to set `start`, `stop`, and `step`.
PK_API void py_newslice(py_OutRef);

/// Create a `nativefunc` object.
PK_API void py_newnativefunc(py_OutRef, py_CFunction);

/// Create a `function` object.
PK_API py_Name py_newfunction(py_OutRef out,
                                 const char* sig,
                                 py_CFunction f,
                                 const char* docstring,
                                 int slots);

/// Create a `boundmethod` object.
PK_API void py_newboundmethod(py_OutRef out, py_Ref self, py_Ref func);

/// Convert a null-terminated string to a name.
PK_API py_Name py_name(const char*);

/// Convert a `c11_sv` to a name.
PK_API py_Name py_namev(c11_sv);

/// Convert a name to a `c11_sv`.
PK_API c11_sv py_name2sv(py_Name);

/// Create a new type.
/// @param name name of the type.
/// @param base base type.
/// @param module module where the type is defined. Use `NULL` for built-in types.
/// @param dtor destructor function. Use `NULL` if not needed.
PK_API py_Type py_newtype(const char* name,
                             py_Type base,
                             const py_GlobalRef module,
                             py_Dtor dtor);

/// Create a new object.
/// @param out output reference.
/// @param type type of the object.
/// @param slots number of slots. Use `-1` to create a `__dict__`.
/// @param udsize size of your userdata.
/// @return pointer to the userdata.
PK_API void* py_newobject(py_OutRef out, py_Type type, int slots, int udsize);

/// Convert an `int` object in python to `int64_t`.
PK_API py_i64 py_toint(py_Ref);

/// Convert a `float` object in python to `double`.
PK_API py_f64 py_tofloat(py_Ref);

/// Cast a `int` or `float` object in python to `double`.
/// If successful, return true and set the value to `out`.
/// Otherwise, return false and raise `TypeError`.
PK_API bool py_castfloat(py_Ref, py_f64* out);

/// 32-bit version of `py_castfloat`.
PK_API bool py_castfloat32(py_Ref, float* out);

/// Cast a `int` object in python to `int64_t`.
PK_API bool py_castint(py_Ref, py_i64* out);

/// Convert a `bool` object in python to `bool`.
PK_API bool py_tobool(py_Ref);

/// Convert a `type` object in python to `py_Type`.
PK_API py_Type py_totype(py_Ref);

/// Convert a `str` object in python to `c11_sv`.
PK_API c11_sv py_tosv(py_Ref);

/// Resize a `bytes` object. It can only be resized down.
PK_API void py_bytes_resize(py_Ref, int size);

/// Convert a user-defined object to its userdata.
PK_API void* py_touserdata(py_Ref);

/// Get the type of the object.
PK_API py_Type py_typeof(py_Ref self);

/// Get type by module and name. e.g. `py_gettype("time", py_name("struct_time"))`.
/// Return `0` if not found.
PK_API py_Type py_gettype(const char* module, py_Name name);

/// Check if the object is exactly the given type.
PK_API bool py_istype(py_Ref, py_Type);

/// Check if the object is an instance of the given type.
PK_API bool py_isinstance(py_Ref obj, py_Type type);

/// Check if the derived type is a subclass of the base type.
PK_API bool py_issubclass(py_Type derived, py_Type base);

/// Get the magic method from the given type only.
/// The returned reference is always valid. However, its value may be `nil`.
PK_API py_GlobalRef py_tpgetmagic(py_Type type, py_Name name);

/// Search the magic method from the given type to the base type.
/// Return `NULL` if not found.
PK_API py_GlobalRef py_tpfindmagic(py_Type, py_Name name);

/// Search the name from the given type to the base type.
/// Return `NULL` if not found.
PK_API py_ItemRef py_tpfindname(py_Type, py_Name name);

/// Get the type object of the given type.
PK_API py_GlobalRef py_tpobject(py_Type type);

/// Call a type to create a new instance.
PK_API bool py_tpcall(py_Type type, int argc, py_Ref argv);

/// Check if the object is an instance of the given type.
/// Raise `TypeError` if the check fails.
PK_API bool py_checktype(py_Ref self, py_Type type);

/// Get the i-th register.
/// All registers are located in a contiguous memory.
PK_API py_GlobalRef py_getreg(int i);

/// Set the i-th register.
PK_API void py_setreg(int i, py_Ref val);

/// Get variable in the `__main__` module.
PK_API py_ItemRef py_getglobal(py_Name name);

/// Set variable in the `__main__` module.
PK_API void py_setglobal(py_Name name, py_Ref val);

/// Get variable in the `builtins` module.
PK_API py_ItemRef py_getbuiltin(py_Name name);

/// Equivalent to `*dst = *src`.
PK_API void py_assign(py_Ref dst, py_Ref src);

/// Get the last return value.
PK_API py_GlobalRef py_retval();

/// Get an item from the object's `__dict__`.
/// Return `NULL` if not found.
PK_API py_ItemRef py_getdict(py_Ref self, py_Name name);

/// Set an item to the object's `__dict__`.
PK_API void py_setdict(py_Ref self, py_Name name, py_Ref val);

/// Delete an item from the object's `__dict__`.
/// Return `true` if the deletion is successful.
PK_API bool py_deldict(py_Ref self, py_Name name);

/// Prepare an insertion to the object's `__dict__`.
PK_API 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_API bool py_applydict(py_Ref self, bool (*f)(py_Name name, py_Ref val, void* ctx), void* ctx);

/// Get the i-th slot of the object.
/// The object must have slots and `i` must be in valid range.
PK_API py_ObjectRef py_getslot(py_Ref self, int i);

/// Set the i-th slot of the object.
PK_API void py_setslot(py_Ref self, int i, py_Ref val);

/// Get the current `function` object on the stack.
/// Return `NULL` if not available.
/// NOTE: This function should be placed at the beginning of your decl-based bindings.
PK_API py_StackRef py_inspect_currentfunction();

/// Get the current `module` object where the code is executed.
/// Return `NULL` if not available.
PK_API py_GlobalRef py_inspect_currentmodule();

/// Bind a function to the object via "decl-based" style.
/// @param obj the target object.
/// @param sig signature of the function. e.g. `add(x, y)`.
/// @param f function to bind.
PK_API void py_bind(py_Ref obj, const char* sig, py_CFunction f);

/// Bind a method to type via "argc-based" style.
/// @param type the target type.
/// @param name name of the method.
/// @param f function to bind.
PK_API void py_bindmethod(py_Type type, const char* name, py_CFunction f);

/// Bind a static method to type via "argc-based" style.
/// @param type the target type.
/// @param name name of the method.
/// @param f function to bind.
PK_API void py_bindstaticmethod(py_Type type, const char* name, py_CFunction f);

/// Bind a function to the object via "argc-based" style.
/// @param obj the target object.
/// @param name name of the function.
/// @param f function to bind.
PK_API void py_bindfunc(py_Ref obj, const char* name, py_CFunction f);

/// Bind a property to type.
/// @param type the target type.
/// @param name name of the property.
/// @param getter getter function.
/// @param setter setter function. Use `NULL` if not needed.
PK_API void py_bindproperty(py_Type type, const char* name, py_CFunction getter, py_CFunction setter);

/// Python equivalent to `getattr(self, name)`.
PK_API bool py_getattr(py_Ref self, py_Name name);

/// Python equivalent to `setattr(self, name, val)`.
PK_API bool py_setattr(py_Ref self, py_Name name, py_Ref val);

/// Python equivalent to `delattr(self, name)`.
PK_API bool py_delattr(py_Ref self, py_Name name);

/// Python equivalent to `self[key]`.
PK_API bool py_getitem(py_Ref self, py_Ref key);

/// Python equivalent to `self[key] = val`.
PK_API bool py_setitem(py_Ref self, py_Ref key, py_Ref val);

/// Python equivalent to `del self[key]`.
PK_API bool py_delitem(py_Ref self, py_Ref key);

/// Perform a binary operation.
/// The result will be set to `py_retval()`.
/// The stack remains unchanged after the operation.
PK_API bool py_binaryop(py_Ref lhs, py_Ref rhs, py_Name op, py_Name rop);

/// Get the i-th object from the top of the stack.
/// `i` should be negative, e.g. (-1) means TOS.
PK_API py_StackRef py_peek(int i);

/// Push the object to the stack.
PK_API void py_push(py_Ref src);

/// Push a `nil` object to the stack.
PK_API void py_pushnil();

/// Push a `None` object to the stack.
PK_API void py_pushnone();

/// Push a `py_Name` to the stack. This is used for keyword arguments.
PK_API void py_pushname(py_Name name);

/// Pop an object from the stack.
PK_API void py_pop();

/// Shrink the stack by n.
PK_API void py_shrink(int n);

/// Get a temporary variable from the stack.
PK_API py_StackRef py_pushtmp();

/// Get the unbound method of the object.
/// Assume the object is located at the top of the stack.
/// If return true:  `[self] -> [unbound, self]`.
/// If return false: `[self] -> [self]` (no change).
PK_API bool py_pushmethod(py_Name name);

/// Call a callable object via pocketpy's calling convention.
/// You need to prepare the stack using this form: `callable, self/nil, arg1, arg2, ..., k1, v1, k2, v2, ...`
/// `argc` is the number of positional arguments excluding `self`.
/// `kwargc` is the number of keyword arguments, i.e. the number of key-value pairs.
/// The result will be set to `py_retval()`.
/// The stack size will be reduced by `2 + argc + kwargc * 2`.
PK_API bool py_vectorcall(uint16_t argc, uint16_t kwargc);

/// Evaluate an expression and push the result to the stack.
/// This function is used for testing.
PK_API bool py_pusheval(const char* expr, py_GlobalRef module);

/// Create a new module.
PK_API py_GlobalRef py_newmodule(const char* path);

/// Get a module by path.
PK_API py_GlobalRef py_getmodule(const char* path);

/// Import a module.
/// The result will be set to `py_retval()`.
/// -1: error, 0: not found, 1: success
PK_API int py_import(const char* path);

/// Raise an exception by type and message. Always return false.
PK_API bool py_exception(py_Type type, const char* fmt, ...);

/// Raise an expection object. Always return false.
PK_API bool py_raise(py_Ref);

/// Print the current exception.
/// The exception will be set as handled.
PK_API void py_printexc();

/// Format the current exception and return a null-terminated string.
/// The result should be freed by the caller.
/// The exception will be set as handled.
PK_API char* py_formatexc();

/// Check if an exception is raised.
PK_API bool py_checkexc(bool ignore_handled);

/// Check if the exception is an instance of the given type.
/// This function is roughly equivalent to python's `except <T> as e:` block.
/// If match, the exception will be stored in `py_retval()` as handled.
PK_API bool py_matchexc(py_Type type);

/// Clear the current exception.
/// @param p0 the unwinding point. Use `NULL` if not needed.
PK_API void py_clearexc(py_StackRef p0);

PK_API bool StopIteration();

PK_API bool KeyError(py_Ref key);

/// Python equivalent to `bool(val)`.
/// 1: true, 0: false, -1: error
PK_API int py_bool(py_Ref val);

/// Compare two objects.
/// 1: lhs == rhs, 0: lhs != rhs, -1: error
PK_API int py_equal(py_Ref lhs, py_Ref rhs);

/// Compare two objects.
/// 1: lhs < rhs, 0: lhs >= rhs, -1: error
PK_API int py_less(py_Ref lhs, py_Ref rhs);

/// Python equivalent to `callable(val)`.
PK_API bool py_callable(py_Ref val);

/// Get the hash value of the object.
PK_API bool py_hash(py_Ref, py_i64* out);

/// Get the iterator of the object.
PK_API bool py_iter(py_Ref);

/// Get the next element from the iterator.
/// 1: success, 0: StopIteration, -1: error
PK_API int py_next(py_Ref);

/// Python equivalent to `lhs is rhs`.
PK_API bool py_isidentical(py_Ref, py_Ref);

/// Call a function.
/// It prepares the stack and then performs a `vectorcall(argc, 0, false)`.
/// The result will be set to `py_retval()`.
/// The stack remains unchanged after the operation.
PK_API bool py_call(py_Ref f, int argc, py_Ref argv);

/// Call a `py_CFunction` in a safe way.
/// This function does extra checks to help you debug `py_CFunction`.
PK_API bool py_callcfunc(py_CFunction f, int argc, py_Ref argv);

/// Python equivalent to `str(val)`.
PK_API bool py_str(py_Ref val);

/// Python equivalent to `repr(val)`.
PK_API bool py_repr(py_Ref val);

/// Python equivalent to `len(val)`.
PK_API bool py_len(py_Ref val);

/// Python equivalent to `json.dumps(val)`.
PK_API bool py_json_dumps(py_Ref val);

/// Python equivalent to `json.loads(val)`.
PK_API bool py_json_loads(const char* source);

/// Python equivalent to `pickle.dumps(val)`.
PK_API bool py_pickle_dumps(py_Ref val);

/// Python equivalent to `pickle.loads(val)`.
PK_API bool py_pickle_loads(const unsigned char* data, int size);

PK_API py_ObjectRef py_tuple_data(py_Ref self);

PK_API py_ObjectRef py_tuple_getitem(py_Ref self, int i);

PK_API void py_tuple_setitem(py_Ref self, int i, py_Ref val);

PK_API int py_tuple_len(py_Ref self);

PK_API py_ItemRef py_list_data(py_Ref self);

PK_API py_ItemRef py_list_getitem(py_Ref self, int i);

PK_API void py_list_setitem(py_Ref self, int i, py_Ref val);

PK_API void py_list_delitem(py_Ref self, int i);

PK_API int py_list_len(py_Ref self);

PK_API void py_list_swap(py_Ref self, int i, int j);

PK_API void py_list_append(py_Ref self, py_Ref val);

PK_API py_ItemRef py_list_emplace(py_Ref self);

PK_API void py_list_clear(py_Ref self);

PK_API void py_list_insert(py_Ref self, int i, py_Ref val);

/// -1: error, 0: not found, 1: found
PK_API int py_dict_getitem(py_Ref self, py_Ref key);

/// true: success, false: error
PK_API bool py_dict_setitem(py_Ref self, py_Ref key, py_Ref val);

/// -1: error, 0: not found, 1: found (and deleted)
PK_API int py_dict_delitem(py_Ref self, py_Ref key);

/// -1: error, 0: not found, 1: found
PK_API int py_dict_getitem_by_str(py_Ref self, const char* key);

/// -1: error, 0: not found, 1: found
PK_API int py_dict_getitem_by_int(py_Ref self, py_i64 key);

/// true: success, false: error
PK_API bool py_dict_setitem_by_str(py_Ref self, const char* key, py_Ref val);

/// true: success, false: error
PK_API bool py_dict_setitem_by_int(py_Ref self, py_i64 key, py_Ref val);

/// -1: error, 0: not found, 1: found (and deleted)
PK_API int py_dict_delitem_by_str(py_Ref self, const char* key);

/// -1: error, 0: not found, 1: found (and deleted)
PK_API int py_dict_delitem_by_int(py_Ref self, py_i64 key);

/// true: success, false: error
PK_API bool py_dict_apply(py_Ref self, bool (*f)(py_Ref key, py_Ref val, void* ctx), void* ctx);

/// noexcept
PK_API int py_dict_len(py_Ref self);

/// An utility function to read a line from stdin for REPL.
PK_API int py_replinput(char* buf, int max_size);