| Index: Objects/rangeobject.c |
| =================================================================== |
| --- Objects/rangeobject.c (revision 62616) |
| +++ Objects/rangeobject.c (working copy) |
| @@ -14,6 +14,7 @@ |
| PyObject *start; |
| PyObject *stop; |
| PyObject *step; |
| + PyObject *length; |
|
mvloewis
2008/05/02 05:43:57
What is the purpose of caching the length in the r
GvR
2008/05/02 13:52:47
On 2008/05/02 05:43:57, mvloewis wrote:
> What is
Benjamin
2008/05/02 16:56:18
On 2008/05/02 05:43:57, mvloewis wrote:
> What is
|
| } rangeobject; |
| /* Helper function for validating step. Always returns a new reference or |
| @@ -43,6 +44,9 @@ |
| return step; |
| } |
| +static PyObject* range_compute_length(PyObject *start, |
| + PyObject *stop, PyObject *step); |
|
GvR
2008/05/02 13:52:47
This line is indented one space too many.
|
| + |
| /* XXX(nnorwitz): should we error check if the user passes any empty ranges? |
| range(-10) |
| range(0, -5) |
| @@ -52,7 +56,7 @@ |
| range_new(PyTypeObject *type, PyObject *args, PyObject *kw) |
| { |
| rangeobject *obj = NULL; |
| - PyObject *start = NULL, *stop = NULL, *step = NULL; |
| + PyObject *start = NULL, *stop = NULL, *step = NULL, *length = NULL; |
| if (!_PyArg_NoKeywords("range()", kw)) |
| return NULL; |
| @@ -81,25 +85,30 @@ |
| goto Fail; |
| } |
| + length = range_compute_length(start, stop, step); |
| + if (length == NULL) |
| + goto Fail; |
| obj = PyObject_New(rangeobject, &PyRange_Type); |
| if (obj == NULL) |
| goto Fail; |
| obj->start = start; |
| obj->stop = stop; |
| obj->step = step; |
| + obj->length = length; |
| return (PyObject *) obj; |
| Fail: |
| Py_XDECREF(start); |
| Py_XDECREF(stop); |
| Py_XDECREF(step); |
| + Py_XDECREF(length); |
| return NULL; |
| } |
| PyDoc_STRVAR(range_doc, |
| "range([start,] stop[, step]) -> range object\n\ |
| \n\ |
| -Returns an iterator that generates the numbers in the range on demand."); |
| +Returns a virtual sequence of numbers from start to stop by step."); |
|
GvR
2008/05/02 13:52:47
I really don't want to use the word sequence here.
|
| static void |
| range_dealloc(rangeobject *r) |
| @@ -107,6 +116,7 @@ |
| Py_DECREF(r->start); |
| Py_DECREF(r->stop); |
| Py_DECREF(r->step); |
| + Py_DECREF(r->length); |
| PyObject_Del(r); |
| } |
| @@ -116,8 +126,8 @@ |
| * Arguments MUST return 1 with either PyLong_Check() or |
| * PyLong_Check(). Return -1 when there is an error. |
|
GvR
2008/05/02 13:52:47
Not your fault, but this comment still references
|
| */ |
| -static PyObject* |
| -range_length_obj(rangeobject *r) |
| +static PyObject * |
| +range_compute_length(PyObject *start, PyObject *stop, PyObject *step) |
| { |
| /* ------------------------------------------------------------- |
| Algorithm is equal to that of get_len_of_range(), but it operates |
| @@ -125,7 +135,6 @@ |
| ---------------------------------------------------------------*/ |
| int cmp_result, cmp_call; |
| PyObject *lo, *hi; |
| - PyObject *step = NULL; |
| PyObject *diff = NULL; |
| PyObject *one = NULL; |
| PyObject *tmp1 = NULL, *tmp2 = NULL, *result; |
| @@ -134,23 +143,22 @@ |
| PyObject *zero = PyLong_FromLong(0); |
| if (zero == NULL) |
| return NULL; |
| - cmp_call = PyObject_Cmp(r->step, zero, &cmp_result); |
| + cmp_call = PyObject_Cmp(step, zero, &cmp_result); |
| Py_DECREF(zero); |
| if (cmp_call == -1) |
| return NULL; |
| assert(cmp_result != 0); |
| if (cmp_result > 0) { |
| - lo = r->start; |
| - hi = r->stop; |
| - step = r->step; |
| + lo = start; |
| + hi = stop; |
| Py_INCREF(step); |
| } else { |
| - lo = r->stop; |
| - hi = r->start; |
| - step = PyNumber_Negative(r->step); |
| + lo = stop; |
| + hi = start; |
| + step = PyNumber_Negative(step); |
| if (!step) |
| - return NULL; |
| + goto Fail; |
| } |
| /* if (lo >= hi), return length of 0. */ |
| @@ -193,46 +201,11 @@ |
| static Py_ssize_t |
| range_length(rangeobject *r) |
| { |
| - PyObject *len = range_length_obj(r); |
| - Py_ssize_t result = -1; |
| - if (len) { |
| - result = PyLong_AsSsize_t(len); |
| - Py_DECREF(len); |
| - } |
| - return result; |
| + return PyLong_AsSsize_t(r->length); |
| } |
| -/* range(...)[x] is necessary for: seq[:] = range(...) */ |
| static PyObject * |
| -range_item(rangeobject *r, Py_ssize_t i) |
| -{ |
| - Py_ssize_t len = range_length(r); |
| - PyObject *rem, *incr, *result; |
| - |
| - /* XXX(nnorwitz): should negative indices be supported? */ |
| - /* XXX(nnorwitz): should support range[x] where x > PY_SSIZE_T_MAX? */ |
| - if (i < 0 || i >= len) { |
| - if (!PyErr_Occurred()) |
| - PyErr_SetString(PyExc_IndexError, |
| - "range object index out of range"); |
| - return NULL; |
| - } |
| - |
| - /* XXX(nnorwitz): optimize for short ints. */ |
| - rem = PyLong_FromSsize_t(i); |
| - if (!rem) |
| - return NULL; |
| - incr = PyNumber_Multiply(rem, r->step); |
| - Py_DECREF(rem); |
| - if (!incr) |
| - return NULL; |
| - result = PyNumber_Add(r->start, incr); |
| - Py_DECREF(incr); |
| - return result; |
| -} |
| - |
| -static PyObject * |
| range_repr(rangeobject *r) |
| { |
| Py_ssize_t istep; |
| @@ -252,12 +225,40 @@ |
| r->start, r->stop, r->step); |
| } |
| +static PyObject * |
| +range_getstart(rangeobject *obj) |
| +{ |
| + return obj->start; |
| +} |
| + |
| +static PyObject * |
| +range_getstop(rangeobject *obj) |
| +{ |
| + return obj->stop; |
| +} |
| + |
| +static PyObject * |
| +range_getstep(rangeobject *obj) |
| +{ |
| + return obj->step; |
| +} |
| + |
| +static PyGetSetDef range_getset[] = { |
| + {"start", (getter)range_getstart, NULL, "The start of the range"}, |
| + {"stop", (getter)range_getstop, NULL, "Where the range stops."}, |
| + {"step", (getter)range_getstep, NULL, "How much the range jumps."}, |
| + {0}, |
| +}; |
| + |
| static PySequenceMethods range_as_sequence = { |
| (lenfunc)range_length, /* sq_length */ |
|
GvR
2008/05/02 13:52:47
The latest discussion on the list suggests to remo
|
| - 0, /* sq_concat */ |
| - 0, /* sq_repeat */ |
| - (ssizeargfunc)range_item, /* sq_item */ |
| - 0, /* sq_slice */ |
| + 0, /* sq_concat */ |
| + 0, /* sq_repeat */ |
| + 0, /* sq_item */ |
| + 0, /* sq_slice */ |
| + 0, /* sq_ass_item */ |
| + 0, /* sq_ass_slice */ |
| + 0, /* sq_contains */ |
| }; |
| static PyObject * range_iter(PyObject *seq); |
| @@ -285,7 +286,7 @@ |
| (reprfunc)range_repr, /* tp_repr */ |
| 0, /* tp_as_number */ |
| &range_as_sequence, /* tp_as_sequence */ |
| - 0, /* tp_as_mapping */ |
| + 0, /* tp_as_mapping */ |
| 0, /* tp_hash */ |
| 0, /* tp_call */ |
| 0, /* tp_str */ |
| @@ -302,7 +303,7 @@ |
| 0, /* tp_iternext */ |
| range_methods, /* tp_methods */ |
| 0, /* tp_members */ |
| - 0, /* tp_getset */ |
| + range_getset, /* tp_getset */ |
|
GvR
2008/05/02 13:52:47
Please use spaces to indent the comment.
|
| 0, /* tp_base */ |
| 0, /* tp_dict */ |
| 0, /* tp_descr_get */ |
| @@ -647,9 +648,7 @@ |
| return NULL; |
| /* start + (len - 1) * step */ |
| - len = range_length_obj(range); |
| - if (!len) |
| - goto create_failure; |
| + len = range->length; |
| one = PyLong_FromLong(1); |
| if (!one) |
