diff options
| -rw-r--r-- | examples/natmod/features4/features4.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/examples/natmod/features4/features4.c b/examples/natmod/features4/features4.c index a52e9e4566..e64c7f7592 100644 --- a/examples/natmod/features4/features4.c +++ b/examples/natmod/features4/features4.c @@ -1,5 +1,6 @@ /* - This example extends on features0 but demonstrates how to define a class. + This example extends on features0 but demonstrates how to define a class, + and a custom exception. The Factorial class constructor takes an integer, and then the calculate method can be called to get the factorial. @@ -8,6 +9,9 @@ >>> f = features4.Factorial(4) >>> f.calculate() 24 + + If the argument to the Factorial class constructor is less than zero, a + FactorialError is raised. */ // Include the header file to get access to the MicroPython API @@ -22,6 +26,8 @@ typedef struct { mp_int_t n; } mp_obj_factorial_t; +mp_obj_full_type_t mp_type_FactorialError; + // 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) { @@ -30,6 +36,10 @@ static mp_obj_t factorial_make_new(const mp_obj_type_t *type, size_t n_args, siz mp_obj_factorial_t *o = mp_obj_malloc(mp_obj_factorial_t, type); o->n = mp_obj_get_int(args_in[0]); + if (o->n < 0) { + mp_raise_msg((mp_obj_type_t *)&mp_type_FactorialError, "argument must be zero or above"); + } + return MP_OBJ_FROM_PTR(o); } @@ -68,6 +78,12 @@ mp_obj_t mpy_init(mp_obj_fun_bc_t *self, size_t n_args, size_t n_kw, mp_obj_t *a // Make the Factorial type available on the module. mp_store_global(MP_QSTR_Factorial, MP_OBJ_FROM_PTR(&mp_type_factorial)); + // Initialise the exception type. + mp_obj_exception_init(&mp_type_FactorialError, MP_QSTR_FactorialError, &mp_type_Exception); + + // Make the FactorialError type available on the module. + mp_store_global(MP_QSTR_FactorialError, MP_OBJ_FROM_PTR(&mp_type_FactorialError)); + // This must be last, it restores the globals dict MP_DYNRUNTIME_INIT_EXIT } |