examples/natmod: Add very simple features0 example to compute factorial.

This commit is contained in:
Damien George 2019-12-16 22:40:22 +11:00
parent b3b9b11596
commit a3df152fef
2 changed files with 54 additions and 0 deletions

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# Location of top-level MicroPython directory
MPY_DIR = ../../..
# Name of module
MOD = features0
# Source files (.c or .py)
SRC = features0.c
# Architecture to build for (x86, x64, armv7m, xtensa, xtensawin)
ARCH = x64
# Include to get the rules for compiling and linking the module
include $(MPY_DIR)/py/dynruntime.mk

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/* This example demonstrates the following features in a native module:
- defining a simple function exposed to Python
- defining a local, helper C function
- getting and creating integer objects
*/
// Include the header file to get access to the MicroPython API
#include "py/dynruntime.h"
// Helper function to compute factorial
STATIC mp_int_t factorial_helper(mp_int_t x) {
if (x == 0) {
return 1;
}
return x * factorial_helper(x - 1);
}
// This is the function which will be called from Python, as factorial(x)
STATIC mp_obj_t factorial(mp_obj_t x_obj) {
// Extract the integer from the MicroPython input object
mp_int_t x = mp_obj_get_int(x_obj);
// Calculate the factorial
mp_int_t result = factorial_helper(x);
// Convert the result to a MicroPython integer object and return it
return mp_obj_new_int(result);
}
// Define a Python reference to the function above
STATIC MP_DEFINE_CONST_FUN_OBJ_1(factorial_obj, factorial);
// 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
// Make the function available in the module's namespace
mp_store_global(MP_QSTR_factorial, MP_OBJ_FROM_PTR(&factorial_obj));
// This must be last, it restores the globals dict
MP_DYNRUNTIME_INIT_EXIT
}