set.c

#include "parts.h"
#include "util.h"

static PyObject *
set_check(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_INT(PySet_Check(obj));
}

static PyObject *
set_checkexact(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_INT(PySet_CheckExact(obj));
}

static PyObject *
frozenset_check(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_INT(PyFrozenSet_Check(obj));
}

static PyObject *
frozenset_checkexact(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_INT(PyFrozenSet_CheckExact(obj));
}

static PyObject *
anyset_check(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_INT(PyAnySet_Check(obj));
}

static PyObject *
anyset_checkexact(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_INT(PyAnySet_CheckExact(obj));
}

static PyObject *
set_new(PyObject *self, PyObject *args)
{
    PyObject *iterable = NULL;
    if (!PyArg_ParseTuple(args, "|O", &iterable)) {
        return NULL;
    }
    return PySet_New(iterable);
}

static PyObject *
frozenset_new(PyObject *self, PyObject *args)
{
    PyObject *iterable = NULL;
    if (!PyArg_ParseTuple(args, "|O", &iterable)) {
        return NULL;
    }
    return PyFrozenSet_New(iterable);
}

static PyObject *
set_size(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_SIZE(PySet_Size(obj));
}

static PyObject *
set_contains(PyObject *self, PyObject *args)
{
    PyObject *obj, *item;
    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
        return NULL;
    }
    NULLABLE(obj);
    NULLABLE(item);
    RETURN_INT(PySet_Contains(obj, item));
}

static PyObject *
set_add(PyObject *self, PyObject *args)
{
    PyObject *obj, *item;
    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
        return NULL;
    }
    NULLABLE(obj);
    NULLABLE(item);
    RETURN_INT(PySet_Add(obj, item));
}

static PyObject *
set_discard(PyObject *self, PyObject *args)
{
    PyObject *obj, *item;
    if (!PyArg_ParseTuple(args, "OO", &obj, &item)) {
        return NULL;
    }
    NULLABLE(obj);
    NULLABLE(item);
    RETURN_INT(PySet_Discard(obj, item));
}

static PyObject *
set_pop(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    return PySet_Pop(obj);
}

static PyObject *
set_clear(PyObject *self, PyObject *obj)
{
    NULLABLE(obj);
    RETURN_INT(PySet_Clear(obj));
}

static PyObject *
test_frozenset_add_in_capi(PyObject *self, PyObject *Py_UNUSED(obj))
{
    // Test that `frozenset` can be used with `PySet_Add`,
    // when frozenset is just created in CAPI.
    PyObject *fs = PyFrozenSet_New(NULL);
    if (fs == NULL) {
        return NULL;
    }
    PyObject *num = PyLong_FromLong(1);
    if (num == NULL) {
        goto error;
    }
    if (PySet_Add(fs, num) < 0) {
        goto error;
    }
    int contains = PySet_Contains(fs, num);
    if (contains < 0) {
        goto error;
    }
    else if (contains == 0) {
        goto unexpected;
    }
    Py_DECREF(fs);
    Py_DECREF(num);
    Py_RETURN_NONE;

unexpected:
    PyErr_SetString(PyExc_ValueError, "set does not contain expected value");
error:
    Py_DECREF(fs);
    Py_XDECREF(num);
    return NULL;
}

static PyObject *
test_set_contains_does_not_convert_unhashable_key(PyObject *self, PyObject *Py_UNUSED(obj))
{
    // The documentation of PySet_Contains state:
    //
    // int PySet_Contains(PyObject *anyset, PyObject *key)
    //
    // Part of the Stable ABI.
    //
    // ... Unlike the Python __contains__() method, this function does not
    // automatically convert unhashable sets [key] into temporary frozensets.
    // Raise a TypeError if the key is unhashable.
    //
    // That is to say {2,3} in {1, 2, frozenset({2,3})}
    //                ^_ will be converted in a frozenset in Python code.
    // But not if using PySet_Contains(..., key)
    //
    // We test that this behavior is unchanged as this is a stable API.

    PyObject *outer_set = PySet_New(NULL);

    PyObject *needle = PySet_New(NULL);
    if (needle == NULL) {
        Py_DECREF(outer_set);
        return NULL;
    }

    PyObject *num = PyLong_FromLong(42);
    if (num == NULL) {
        Py_DECREF(outer_set);
        Py_DECREF(needle);
        return NULL;
    }

    // Add an element to needle to make it {42}
    if (PySet_Add(needle, num) < 0) {
        Py_DECREF(outer_set);
        Py_DECREF(needle);
        Py_DECREF(num);
        return NULL;
    }

    int result = PySet_Contains(outer_set, needle);

    Py_DECREF(num);
    Py_DECREF(needle);
    Py_DECREF(outer_set);

    if (result < 0) {
        if (PyErr_ExceptionMatches(PyExc_TypeError)) {
            PyErr_Clear();
            Py_RETURN_NONE;
        }
        return NULL;
    }

    PyErr_SetString(PyExc_AssertionError,
                    "PySet_Contains should have raised TypeError for unhashable key");
    return NULL;
}

static PyMethodDef test_methods[] = {
    {"set_check", set_check, METH_O},
    {"set_checkexact", set_checkexact, METH_O},
    {"frozenset_check", frozenset_check, METH_O},
    {"frozenset_checkexact", frozenset_checkexact, METH_O},
    {"anyset_check", anyset_check, METH_O},
    {"anyset_checkexact", anyset_checkexact, METH_O},

    {"set_new", set_new, METH_VARARGS},
    {"frozenset_new", frozenset_new, METH_VARARGS},

    {"set_size", set_size, METH_O},
    {"set_contains", set_contains, METH_VARARGS},
    {"set_add", set_add, METH_VARARGS},
    {"set_discard", set_discard, METH_VARARGS},
    {"set_pop", set_pop, METH_O},
    {"set_clear", set_clear, METH_O},

    {"test_frozenset_add_in_capi", test_frozenset_add_in_capi, METH_NOARGS},
    {"test_set_contains_does_not_convert_unhashable_key",
     test_set_contains_does_not_convert_unhashable_key, METH_NOARGS},

    {NULL},
};

int
_PyTestLimitedCAPI_Init_Set(PyObject *m)
{
    if (PyModule_AddFunctions(m, test_methods) < 0) {
        return -1;
    }

    return 0;
}