diff options
| -rw-r--r-- | Doc/library/functions.rst | 3 | ||||
| -rw-r--r-- | Lib/test/test_capi/test_misc.py | 7 | ||||
| -rw-r--r-- | Lib/test/test_doctest.py | 2 | ||||
| -rw-r--r-- | Lib/test/test_slice.py | 12 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2023-02-11-23-14-06.gh-issue-84783._P5sMa.rst | 1 | ||||
| -rw-r--r-- | Objects/sliceobject.c | 38 | ||||
| -rw-r--r-- | Objects/tupleobject.c | 2 |
7 files changed, 53 insertions, 12 deletions
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst index 658d676..3ff2884 100644 --- a/Doc/library/functions.rst +++ b/Doc/library/functions.rst @@ -1635,6 +1635,9 @@ are always available. They are listed here in alphabetical order. example: ``a[start:stop:step]`` or ``a[start:stop, i]``. See :func:`itertools.islice` for an alternate version that returns an iterator. + .. versionchanged:: 3.12 + Slice objects are now :term:`hashable` (provided :attr:`~slice.start`, + :attr:`~slice.stop`, and :attr:`~slice.step` are hashable). .. function:: sorted(iterable, /, *, key=None, reverse=False) diff --git a/Lib/test/test_capi/test_misc.py b/Lib/test/test_capi/test_misc.py index f26b472..ad099c6 100644 --- a/Lib/test/test_capi/test_misc.py +++ b/Lib/test/test_capi/test_misc.py @@ -419,11 +419,6 @@ class CAPITest(unittest.TestCase): with self.assertRaises(TypeError): _testcapi.sequence_set_slice(None, 1, 3, 'xy') - mapping = {1: 'a', 2: 'b', 3: 'c'} - with self.assertRaises(TypeError): - _testcapi.sequence_set_slice(mapping, 1, 3, 'xy') - self.assertEqual(mapping, {1: 'a', 2: 'b', 3: 'c'}) - def test_sequence_del_slice(self): # Correct case: data = [1, 2, 3, 4, 5] @@ -459,7 +454,7 @@ class CAPITest(unittest.TestCase): _testcapi.sequence_del_slice(None, 1, 3) mapping = {1: 'a', 2: 'b', 3: 'c'} - with self.assertRaises(TypeError): + with self.assertRaises(KeyError): _testcapi.sequence_del_slice(mapping, 1, 3) self.assertEqual(mapping, {1: 'a', 2: 'b', 3: 'c'}) diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py index 65e215f..3491d4c 100644 --- a/Lib/test/test_doctest.py +++ b/Lib/test/test_doctest.py @@ -707,7 +707,7 @@ plain ol' Python and is guaranteed to be available. >>> import builtins >>> tests = doctest.DocTestFinder().find(builtins) - >>> 825 < len(tests) < 845 # approximate number of objects with docstrings + >>> 830 < len(tests) < 850 # approximate number of objects with docstrings True >>> real_tests = [t for t in tests if len(t.examples) > 0] >>> len(real_tests) # objects that actually have doctests diff --git a/Lib/test/test_slice.py b/Lib/test/test_slice.py index 03fde32..c35a229 100644 --- a/Lib/test/test_slice.py +++ b/Lib/test/test_slice.py @@ -80,10 +80,16 @@ class SliceTest(unittest.TestCase): self.assertEqual(repr(slice(1, 2, 3)), "slice(1, 2, 3)") def test_hash(self): - # Verify clearing of SF bug #800796 - self.assertRaises(TypeError, hash, slice(5)) + self.assertEqual(hash(slice(5)), slice(5).__hash__()) + self.assertEqual(hash(slice(1, 2)), slice(1, 2).__hash__()) + self.assertEqual(hash(slice(1, 2, 3)), slice(1, 2, 3).__hash__()) + self.assertNotEqual(slice(5), slice(6)) + + with self.assertRaises(TypeError): + hash(slice(1, 2, [])) + with self.assertRaises(TypeError): - slice(5).__hash__() + hash(slice(4, {})) def test_cmp(self): s1 = slice(1, 2, 3) diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-02-11-23-14-06.gh-issue-84783._P5sMa.rst b/Misc/NEWS.d/next/Core and Builtins/2023-02-11-23-14-06.gh-issue-84783._P5sMa.rst new file mode 100644 index 0000000..e1c851a --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2023-02-11-23-14-06.gh-issue-84783._P5sMa.rst @@ -0,0 +1 @@ +Make the slice object hashable. diff --git a/Objects/sliceobject.c b/Objects/sliceobject.c index 5694bd9..5d2e6ad 100644 --- a/Objects/sliceobject.c +++ b/Objects/sliceobject.c @@ -628,6 +628,42 @@ slice_traverse(PySliceObject *v, visitproc visit, void *arg) return 0; } +/* code based on tuplehash() of Objects/tupleobject.c */ +#if SIZEOF_PY_UHASH_T > 4 +#define _PyHASH_XXPRIME_1 ((Py_uhash_t)11400714785074694791ULL) +#define _PyHASH_XXPRIME_2 ((Py_uhash_t)14029467366897019727ULL) +#define _PyHASH_XXPRIME_5 ((Py_uhash_t)2870177450012600261ULL) +#define _PyHASH_XXROTATE(x) ((x << 31) | (x >> 33)) /* Rotate left 31 bits */ +#else +#define _PyHASH_XXPRIME_1 ((Py_uhash_t)2654435761UL) +#define _PyHASH_XXPRIME_2 ((Py_uhash_t)2246822519UL) +#define _PyHASH_XXPRIME_5 ((Py_uhash_t)374761393UL) +#define _PyHASH_XXROTATE(x) ((x << 13) | (x >> 19)) /* Rotate left 13 bits */ +#endif + +static Py_hash_t +slicehash(PySliceObject *v) +{ + Py_uhash_t acc = _PyHASH_XXPRIME_5; +#define _PyHASH_SLICE_PART(com) { \ + Py_uhash_t lane = PyObject_Hash(v->com); \ + if(lane == (Py_uhash_t)-1) { \ + return -1; \ + } \ + acc += lane * _PyHASH_XXPRIME_2; \ + acc = _PyHASH_XXROTATE(acc); \ + acc *= _PyHASH_XXPRIME_1; \ +} + _PyHASH_SLICE_PART(start); + _PyHASH_SLICE_PART(stop); + _PyHASH_SLICE_PART(step); +#undef _PyHASH_SLICE_PART + if(acc == (Py_uhash_t)-1) { + return 1546275796; + } + return acc; +} + PyTypeObject PySlice_Type = { PyVarObject_HEAD_INIT(&PyType_Type, 0) "slice", /* Name of this type */ @@ -642,7 +678,7 @@ PyTypeObject PySlice_Type = { 0, /* tp_as_number */ 0, /* tp_as_sequence */ 0, /* tp_as_mapping */ - PyObject_HashNotImplemented, /* tp_hash */ + (hashfunc)slicehash, /* tp_hash */ 0, /* tp_call */ 0, /* tp_str */ PyObject_GenericGetAttr, /* tp_getattro */ diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c index e1b9953..7d6d0e1 100644 --- a/Objects/tupleobject.c +++ b/Objects/tupleobject.c @@ -288,7 +288,7 @@ error: /* Hash for tuples. This is a slightly simplified version of the xxHash non-cryptographic hash: - - we do not use any parallellism, there is only 1 accumulator. + - we do not use any parallelism, there is only 1 accumulator. - we drop the final mixing since this is just a permutation of the output space: it does not help against collisions. - at the end, we mangle the length with a single constant. |