Sequence methods, add repeat().

paulross · paulross · commit e8a2c03c1552 · 2025-03-17T13:11:14.000Z
diff --git a/doc/sphinx/source/new_types.rst b/doc/sphinx/source/new_types.rst
@@ -633,7 +633,7 @@ Tests are in ``tests/unit/test_c_seqobject.py``:
      - ``PyObject *(*binaryfunc)(PyObject*, PyObject*)``
    * - Description
      - Takes two sequences and returns a new third one with the first and second concatenated.
-       This is used by the ``+`` operator.
+       This is used by the ``+`` Python operator and the `PySequence_Concat()`_ C API.
 
 Implementation
 --------------
@@ -690,7 +690,6 @@ In ``src/cpy/Object/cSeqObject.c``:
         return ret;
     }
 
-
 Tests
 --------------
 
@@ -708,9 +707,126 @@ Tests are in ``tests/unit/test_c_seqobject.py``:
         assert len(obj) == 6
         assert list(obj) == [7, 4, 1, ] + [70, 40, 100, ]
 
+---------------
+``sq_repeat``
+---------------
+
+.. list-table:: Sequence Methods: ``sq_concat``
+   :widths: 20 80
+   :header-rows: 0
+
+   * - Member
+     - `sq_repeat`_
+   * - Function type
+     - `ssizeargfunc`_
+   * - Function signature
+     - ``PyObject *(*ssizeargfunc)(PyObject*, Py_ssize_t)``
+   * - Description
+     - Returns a new sequence with the old one repeated the given number of times times.
+       This is used by the ``*`` Python operator and the `PySequence_Repeat()`_ C API.
+
+Implementation
+--------------
+
+The implementation is fairly straightforward in ``src/cpy/Object/cSeqObject.c``.
+Note that ``count`` can be zero or negative:
+
+.. code-block:: c
+
+    /** Return a new sequence which contains the old one repeated count times. */
+    static PyObject *
+    SequenceLongObject_sq_repeat(PyObject *self, Py_ssize_t count) {
+        PyObject *ret = SequenceLongObject_new(&SequenceLongObjectType, NULL, NULL);
+        if (!ret) {
+            assert(PyErr_Occurred());
+            return NULL;
+        }
+        assert(ret != self);
+        if (((SequenceLongObject *) self)->size > 0 && count > 0) {
+            /* For convenience. */
+            SequenceLongObject *self_as_slo = (SequenceLongObject *) self;
+            SequenceLongObject *ret_as_slo = (SequenceLongObject *) ret;
+            ret_as_slo->size = self_as_slo->size * count;
+            assert(ret_as_slo->size > 0);
+            ret_as_slo->array_long = malloc(ret_as_slo->size * sizeof(long));
+            if (!ret_as_slo->array_long) {
+                PyErr_Format(PyExc_MemoryError, "%s(): Can not create new object.", __FUNCTION__);
+                Py_DECREF(ret);
+                return NULL;
+            }
+            Py_ssize_t ret_index = 0;
+            for (Py_ssize_t i = 0; i < count; ++i) {
+                for (Py_ssize_t j = 0; j < self_as_slo->size; ++j) {
+                    ret_as_slo->array_long[ret_index] = self_as_slo->array_long[j];
+                    ++ret_index;
+                }
+            }
+        } else {
+            /* Empty sequence. */
+        }
+        return ret;
+    }
+
+Tests
+--------------
+
+Tests are in ``tests/unit/test_c_seqobject.py``:
+
+.. code-block:: python
+
+    @pytest.mark.parametrize(
+        'initial_sequence, count, expected',
+        (
+            (
+                [], 1, [],
+            ),
+            (
+                [7, 4, 1, ], 0, [],
+            ),
+            (
+                [7, 4, 1, ], -1, [],
+            ),
+            (
+                [7, 4, 1, ], 1, [7, 4, 1, ],
+            ),
+            (
+                [7, 4, 1, ], 2, [7, 4, 1, 7, 4, 1, ],
+            ),
+            (
+                [7, 4, 1, ], 3, [7, 4, 1, 7, 4, 1, 7, 4, 1, ],
+            ),
+        )
+    )
+    def test_SequenceLongObject_repeat(initial_sequence, count, expected):
+        obj_a = cSeqObject.SequenceLongObject(initial_sequence)
+        obj = obj_a * count
+        print()
+        assert id(obj_a) != id(obj)
+        assert list(obj) == expected
+        assert list(obj) == (list(obj_a) * count)
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
 
 
-TOOD:
+TODO:
 
 ====================================
 TODOs:
diff --git a/src/cpy/Object/cSeqObject.c b/src/cpy/Object/cSeqObject.c
@@ -145,6 +145,50 @@ SequenceLongObject_sq_concat(PyObject *self, PyObject *other) {
     return ret;
 }
 
+/**
+ * Return a new sequence which contains the old one repeated count times.
+ * @param self
+ * @param count
+ * @return
+ */
+static PyObject *
+SequenceLongObject_sq_repeat(PyObject *self, Py_ssize_t count) {
+    PyObject *ret = SequenceLongObject_new(&SequenceLongObjectType, NULL, NULL);
+    if (!ret) {
+        assert(PyErr_Occurred());
+        return NULL;
+    }
+    assert(ret != self);
+    if (((SequenceLongObject *) self)->size > 0 && count > 0) {
+        /* For convenience. */
+        SequenceLongObject *self_as_slo = (SequenceLongObject *) self;
+        SequenceLongObject *ret_as_slo = (SequenceLongObject *) ret;
+        ret_as_slo->size = self_as_slo->size * count;
+        assert(ret_as_slo->size > 0);
+        ret_as_slo->array_long = malloc(ret_as_slo->size * sizeof(long));
+        if (!ret_as_slo->array_long) {
+            PyErr_Format(PyExc_MemoryError, "%s(): Can not create new object.", __FUNCTION__);
+            Py_DECREF(ret);
+            return NULL;
+        }
+        Py_ssize_t ret_index = 0;
+        for (Py_ssize_t i = 0; i < count; ++i) {
+//            fprintf(stdout, "%s(): Setting %p Count %zd\n", __FUNCTION__, (void *) ret, i);
+            for (Py_ssize_t j = 0; j < self_as_slo->size; ++j) {
+//                fprintf(
+//                    stdout, "%s(): Setting %p [%zd] to %zd\n",
+//                    __FUNCTION__, (void *) ret, ret_index, self_as_slo->array_long[j]
+//                );
+                ret_as_slo->array_long[ret_index] = self_as_slo->array_long[j];
+                ++ret_index;
+            }
+        }
+    } else {
+        /* Empty sequence. */
+    }
+    return ret;
+}
+
 static PyObject *
 SequenceLongObject_sq_item(PyObject *self, Py_ssize_t index) {
 //    fprintf(stdout, "%s(): index=%zd\n", __FUNCTION__, index);
@@ -168,7 +212,7 @@ SequenceLongObject_sq_item(PyObject *self, Py_ssize_t index) {
 PySequenceMethods SequenceLongObject_sequence_methods = {
         .sq_length = &SequenceLongObject_sq_length,
         .sq_concat = &SequenceLongObject_sq_concat,
-        .sq_repeat = NULL,
+        .sq_repeat = &SequenceLongObject_sq_repeat,
         .sq_item = &SequenceLongObject_sq_item,
         .sq_ass_item = NULL,
         .sq_contains = NULL,
diff --git a/tests/unit/test_c_seqobject.py b/tests/unit/test_c_seqobject.py
@@ -31,11 +31,13 @@ def test_SequenceLongObject_dir():
         '__le__',
         '__len__',
         '__lt__',
+        '__mul__',
         '__ne__',
         '__new__',
         '__reduce__',
         '__reduce_ex__',
         '__repr__',
+        '__rmul__',
         '__setattr__',
         '__sizeof__',
         '__str__',
@@ -61,6 +63,38 @@ def test_SequenceLongObject_concat():
     assert len(obj) == 6
     assert list(obj) == [7, 4, 1, ] + [70, 40, 100, ]
 
+
+@pytest.mark.parametrize(
+    'initial_sequence, count, expected',
+    (
+        (
+            [], 1, [],
+        ),
+        (
+            [7, 4, 1, ], 0, [],
+        ),
+        (
+            [7, 4, 1, ], -1, [],
+        ),
+        (
+            [7, 4, 1, ], 1, [7, 4, 1, ],
+        ),
+        (
+            [7, 4, 1, ], 2, [7, 4, 1, 7, 4, 1, ],
+        ),
+        (
+            [7, 4, 1, ], 3, [7, 4, 1, 7, 4, 1, 7, 4, 1, ],
+        ),
+    )
+)
+def test_SequenceLongObject_repeat(initial_sequence, count, expected):
+    obj_a = cSeqObject.SequenceLongObject(initial_sequence)
+    obj = obj_a * count
+    print()
+    assert id(obj_a) != id(obj)
+    assert list(obj) == expected
+    assert list(obj) == (list(obj_a) * count)
+
 # @pytest.mark.skipif(not (sys.version_info.minor < 7), reason='Python < 3.7')
 # def test_str_dir_pre_37():
 #     s = cObject.Str()
