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authorMark Dickinson <mdickinson@enthought.com>2011-10-23 18:53:01 (GMT)
committerMark Dickinson <mdickinson@enthought.com>2011-10-23 18:53:01 (GMT)
commit36645681c8ad9a30d142f1dabb44d1d6c3ed5fab (patch)
treeb98250ba008c4e858e44563e12f232d5ccfb8dd9 /Objects/rangeobject.c
parenta2a2e480f335b8758a159ea72ab0067127d1d303 (diff)
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Issue #13201: equality for range objects is now based on equality of the underlying sequences. Thanks Sven Marnach for the patch.
Diffstat (limited to 'Objects/rangeobject.c')
-rw-r--r--Objects/rangeobject.c135
1 files changed, 133 insertions, 2 deletions
diff --git a/Objects/rangeobject.c b/Objects/rangeobject.c
index 58d373c..c1e9e54 100644
--- a/Objects/rangeobject.c
+++ b/Objects/rangeobject.c
@@ -609,6 +609,137 @@ range_contains(rangeobject *r, PyObject *ob)
PY_ITERSEARCH_CONTAINS);
}
+/* Compare two range objects. Return 1 for equal, 0 for not equal
+ and -1 on error. The algorithm is roughly the C equivalent of
+
+ if r0 is r1:
+ return True
+ if len(r0) != len(r1):
+ return False
+ if not len(r0):
+ return True
+ if r0.start != r1.start:
+ return False
+ if len(r0) == 1:
+ return True
+ return r0.step == r1.step
+*/
+static int
+range_equals(rangeobject *r0, rangeobject *r1)
+{
+ int cmp_result;
+ PyObject *one;
+
+ if (r0 == r1)
+ return 1;
+ cmp_result = PyObject_RichCompareBool(r0->length, r1->length, Py_EQ);
+ /* Return False or error to the caller. */
+ if (cmp_result != 1)
+ return cmp_result;
+ cmp_result = PyObject_Not(r0->length);
+ /* Return True or error to the caller. */
+ if (cmp_result != 0)
+ return cmp_result;
+ cmp_result = PyObject_RichCompareBool(r0->start, r1->start, Py_EQ);
+ /* Return False or error to the caller. */
+ if (cmp_result != 1)
+ return cmp_result;
+ one = PyLong_FromLong(1);
+ if (!one)
+ return -1;
+ cmp_result = PyObject_RichCompareBool(r0->length, one, Py_EQ);
+ Py_DECREF(one);
+ /* Return True or error to the caller. */
+ if (cmp_result != 0)
+ return cmp_result;
+ return PyObject_RichCompareBool(r0->step, r1->step, Py_EQ);
+}
+
+static PyObject *
+range_richcompare(PyObject *self, PyObject *other, int op)
+{
+ int result;
+
+ if (!PyRange_Check(other))
+ Py_RETURN_NOTIMPLEMENTED;
+ switch (op) {
+ case Py_NE:
+ case Py_EQ:
+ result = range_equals((rangeobject*)self, (rangeobject*)other);
+ if (result == -1)
+ return NULL;
+ if (op == Py_NE)
+ result = !result;
+ if (result)
+ Py_RETURN_TRUE;
+ else
+ Py_RETURN_FALSE;
+ case Py_LE:
+ case Py_GE:
+ case Py_LT:
+ case Py_GT:
+ Py_RETURN_NOTIMPLEMENTED;
+ default:
+ PyErr_BadArgument();
+ return NULL;
+ }
+}
+
+/* Hash function for range objects. Rough C equivalent of
+
+ if not len(r):
+ return hash((len(r), None, None))
+ if len(r) == 1:
+ return hash((len(r), r.start, None))
+ return hash((len(r), r.start, r.step))
+*/
+static Py_hash_t
+range_hash(rangeobject *r)
+{
+ PyObject *t;
+ Py_hash_t result = -1;
+ int cmp_result;
+
+ t = PyTuple_New(3);
+ if (!t)
+ return -1;
+ Py_INCREF(r->length);
+ PyTuple_SET_ITEM(t, 0, r->length);
+ cmp_result = PyObject_Not(r->length);
+ if (cmp_result == -1)
+ goto end;
+ if (cmp_result == 1) {
+ Py_INCREF(Py_None);
+ Py_INCREF(Py_None);
+ PyTuple_SET_ITEM(t, 1, Py_None);
+ PyTuple_SET_ITEM(t, 2, Py_None);
+ }
+ else {
+ PyObject *one;
+ Py_INCREF(r->start);
+ PyTuple_SET_ITEM(t, 1, r->start);
+ one = PyLong_FromLong(1);
+ if (!one)
+ goto end;
+ cmp_result = PyObject_RichCompareBool(r->length, one, Py_EQ);
+ Py_DECREF(one);
+ if (cmp_result == -1)
+ goto end;
+ if (cmp_result == 1) {
+ Py_INCREF(Py_None);
+ PyTuple_SET_ITEM(t, 2, Py_None);
+ }
+ else {
+ Py_INCREF(r->step);
+ PyTuple_SET_ITEM(t, 2, r->step);
+ }
+ }
+ result = PyObject_Hash(t);
+ end:
+ Py_DECREF(t);
+ return result;
+}
+
static PyObject *
range_count(rangeobject *r, PyObject *ob)
{
@@ -763,7 +894,7 @@ PyTypeObject PyRange_Type = {
0, /* tp_as_number */
&range_as_sequence, /* tp_as_sequence */
&range_as_mapping, /* tp_as_mapping */
- 0, /* tp_hash */
+ (hashfunc)range_hash, /* tp_hash */
0, /* tp_call */
0, /* tp_str */
PyObject_GenericGetAttr, /* tp_getattro */
@@ -773,7 +904,7 @@ PyTypeObject PyRange_Type = {
range_doc, /* tp_doc */
0, /* tp_traverse */
0, /* tp_clear */
- 0, /* tp_richcompare */
+ range_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
range_iter, /* tp_iter */
0, /* tp_iternext */