Add a format specifier %R to PyUnicode_FromFormat(), which embeds

the result of a call to PyObject_Repr() into the string. This makes
it possible to simplify many repr implementations.

PyUnicode_FromFormat() uses two steps to create the final string: A first
pass through the format string determines the size of the final string and
a second pass creates the string. To avoid calling PyObject_Repr() twice
for each %R specifier, PyObject_Repr() is called during the size
calculation step and the results are stored in an array (whose size is
determined at the start by counting %R specifiers).

1 files changed, 1 insertions, 12 deletions

diff --git a/Objects/sliceobject.c b/Objects/sliceobject.c
index d526a07..a30edef 100644
--- a/Objects/sliceobject.c
+++ b/Objects/sliceobject.c
@@ -226,18 +226,7 @@ slice_dealloc(PySliceObject *r)
 static PyObject *
 slice_repr(PySliceObject *r)
 {
-	PyObject *s, *comma;
-
-	s = PyUnicode_FromString("slice(");
-	comma = PyUnicode_FromString(", ");
-	PyUnicode_AppendAndDel(&s, PyObject_Repr(r->start));
-	PyUnicode_Append(&s, comma);
-	PyUnicode_AppendAndDel(&s, PyObject_Repr(r->stop));
-	PyUnicode_Append(&s, comma);
-	PyUnicode_AppendAndDel(&s, PyObject_Repr(r->step));
-	PyUnicode_AppendAndDel(&s, PyUnicode_FromString(")"));
-	Py_DECREF(comma);
-	return s;
+	return PyUnicode_FromFormat("slice(%R, %R, %R)", r->start, r->stop, r->step);
 }
 
 static PyMemberDef slice_members[] = {