circuitpython/examples/natmod/features4/features4.c
Jim Mussared 607548f32d examples/natmod: Add features4 as a class definition example.
Also provide a basic README.md for dynamic native modules.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2023-09-02 00:16:16 +10:00

74 lines
2.6 KiB
C

/*
This example extends on features0 but demonstrates how to define a class.
The Factorial class constructor takes an integer, and then the calculate
method can be called to get the factorial.
>>> import features4
>>> f = features4.Factorial(4)
>>> f.calculate()
24
*/
// Include the header file to get access to the MicroPython API
#include "py/dynruntime.h"
// This is type(Factorial)
mp_obj_full_type_t mp_type_factorial;
// This is the internal state of a Factorial instance.
typedef struct {
mp_obj_base_t base;
mp_int_t n;
} mp_obj_factorial_t;
// Essentially Factorial.__new__ (but also kind of __init__).
// Takes a single argument (the number to find the factorial of)
STATIC mp_obj_t factorial_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args_in) {
mp_arg_check_num(n_args, n_kw, 1, 1, false);
mp_obj_factorial_t *o = mp_obj_malloc(mp_obj_factorial_t, type);
o->n = mp_obj_get_int(args_in[0]);
return MP_OBJ_FROM_PTR(o);
}
STATIC mp_int_t factorial_helper(mp_int_t x) {
if (x == 0) {
return 1;
}
return x * factorial_helper(x - 1);
}
// Implements Factorial.calculate()
STATIC mp_obj_t factorial_calculate(mp_obj_t self_in) {
mp_obj_factorial_t *self = MP_OBJ_TO_PTR(self_in);
return mp_obj_new_int(factorial_helper(self->n));
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(factorial_calculate_obj, factorial_calculate);
// Locals dict for the Factorial type (will have a single method, calculate,
// added in mpy_init).
mp_map_elem_t factorial_locals_dict_table[1];
STATIC MP_DEFINE_CONST_DICT(factorial_locals_dict, factorial_locals_dict_table);
// This is the entry point and is called when the module is imported
mp_obj_t mpy_init(mp_obj_fun_bc_t *self, size_t n_args, size_t n_kw, mp_obj_t *args) {
// This must be first, it sets up the globals dict and other things
MP_DYNRUNTIME_INIT_ENTRY
// Initialise the type.
mp_type_factorial.base.type = (void*)&mp_type_type;
mp_type_factorial.flags = MP_TYPE_FLAG_NONE;
mp_type_factorial.name = MP_QSTR_Factorial;
MP_OBJ_TYPE_SET_SLOT(&mp_type_factorial, make_new, factorial_make_new, 0);
factorial_locals_dict_table[0] = (mp_map_elem_t){ MP_OBJ_NEW_QSTR(MP_QSTR_calculate), MP_OBJ_FROM_PTR(&factorial_calculate_obj) };
MP_OBJ_TYPE_SET_SLOT(&mp_type_factorial, locals_dict, (void*)&factorial_locals_dict, 1);
// Make the Factorial type available on the module.
mp_store_global(MP_QSTR_Factorial, MP_OBJ_FROM_PTR(&mp_type_factorial));
// This must be last, it restores the globals dict
MP_DYNRUNTIME_INIT_EXIT
}