Function _npy_parse_arguments

numpy/core/src/common/npy_argparse.c:267–422

* Generic helper for argument parsing * * See macro version for an example pattern of how to use this function. * * @param funcname * @param cache * @param args Python passed args (METH_FASTCALL) * @param len_args * @param kwnames * @param ... List of arguments (see macro version). * * @return Returns 0 on success and -1 on failure. */

 * @return Returns 0 on success and -1 on failure.
 */
NPY_NO_EXPORT int
_npy_parse_arguments(const char *funcname,
         /* cache_ptr is a NULL initialized persistent storage for data */
        _NpyArgParserCache *cache,
        PyObject *const *args, Py_ssize_t len_args, PyObject *kwnames,
        /* ... is NULL, NULL, NULL terminated: name, converter, value */
        ...)
{
    if (NPY_UNLIKELY(cache->npositional == -1)) {
        va_list va;
        va_start(va, kwnames);

        int res = initialize_keywords(funcname, cache, va);
        va_end(va);
        if (res < 0) {
            return -1;
        }
    }

    if (NPY_UNLIKELY(len_args > cache->npositional)) {
        return raise_incorrect_number_of_positional_args(
                funcname, cache, len_args);
    }

    /* NOTE: Could remove the limit but too many kwargs are slow anyway. */
    PyObject *all_arguments[NPY_MAXARGS];

    for (Py_ssize_t i = 0; i < len_args; i++) {
        all_arguments[i] = args[i];
    }

    /* Without kwargs, do not iterate all converters. */
    int max_nargs = (int)len_args;
    Py_ssize_t len_kwargs = 0;

    /* If there are any kwargs, first handle them */
    if (NPY_LIKELY(kwnames != NULL)) {
        len_kwargs = PyTuple_GET_SIZE(kwnames);
        max_nargs = cache->nargs;

        for (int i = len_args; i < cache->nargs; i++) {
            all_arguments[i] = NULL;
        }

        for (Py_ssize_t i = 0; i < len_kwargs; i++) {
            PyObject *key = PyTuple_GET_ITEM(kwnames, i);
            PyObject *value = args[i + len_args];
            PyObject *const *name;

            /* Super-fast path, check identity: */
            for (name = cache->kw_strings; *name != NULL; name++) {
                if (*name == key) {
                    break;
                }
            }
            if (NPY_UNLIKELY(*name == NULL)) {
                /* Slow fallback, if identity checks failed for some reason */
                for (name = cache->kw_strings; *name != NULL; name++) {