Objects/rangeobject.c

   1 /***********************************************************
   2 Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
   3 The Netherlands.
   4
   5                         All Rights Reserved
   6
   7 Permission to use, copy, modify, and distribute this software and its
   8 documentation for any purpose and without fee is hereby granted,
   9 provided that the above copyright notice appear in all copies and that
  10 both that copyright notice and this permission notice appear in
  11 supporting documentation, and that the names of Stichting Mathematisch
  12 Centrum or CWI or Corporation for National Research Initiatives or
  13 CNRI not be used in advertising or publicity pertaining to
  14 distribution of the software without specific, written prior
  15 permission.
  16
  17 While CWI is the initial source for this software, a modified version
  18 is made available by the Corporation for National Research Initiatives
  19 (CNRI) at the Internet address ftp://ftp.python.org.
  20
  21 STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
  22 REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
  23 MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
  24 CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
  25 DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  26 PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  27 TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  28 PERFORMANCE OF THIS SOFTWARE.
  29
  30 ******************************************************************/
  31
  32 /* Range object implementation */
  33
  34 #include "Python.h"
  35
  36 typedef struct {
  37         PyObject_HEAD
  38         long    start;
  39         long    step;
  40         long    len;
  41         int     reps;
  42 } rangeobject;
  43
  44
  45 PyObject *
  46 PyRange_New(start, len, step, reps)
  47         long start, len, step;
  48         int reps;
  49 {
  50         rangeobject *obj = PyObject_NEW(rangeobject, &PyRange_Type);
  51
  52         obj->start = start;
  53         obj->len   = len;
  54         obj->step  = step;
  55         obj->reps  = reps;
  56
  57         return (PyObject *) obj;
  58 }
  59
  60 static void
  61 range_dealloc(r)
  62         rangeobject *r;
  63 {
  64         PyMem_DEL(r);
  65 }
  66
  67 static PyObject *
  68 range_item(r, i)
  69         rangeobject *r;
  70         int i;
  71 {
  72         if (i < 0 || i >= r->len * r->reps) {
  73                 PyErr_SetString(PyExc_IndexError,
  74                                 "range object index out of range");
  75                 return NULL;
  76         }
  77
  78         return PyInt_FromLong(r->start + (i % r->len) * r->step);
  79 }
  80
  81 static int
  82 range_length(r)
  83         rangeobject *r;
  84 {
  85         return r->len * r->reps;
  86 }
  87
  88 static int
  89 range_print(r, fp, flags)
  90         rangeobject *r;
  91         FILE *fp;
  92         int flags;
  93 {
  94         int i, j;
  95
  96         fprintf(fp, "(");
  97         for (i = 0; i < r->reps; ++i)
  98                 for (j = 0; j < r->len; ++j) {
  99                         if (j > 0 || i > 0)
 100                                 fprintf(fp, ", ");
 101
 102                         fprintf(fp, "%ld", r->start + j * r->step);
 103                 }
 104
 105         if (r->len == 1 && r->reps == 1)
 106                 fprintf(fp, ",");
 107         fprintf(fp, ")");
 108         return 0;
 109 }
 110
 111 static PyObject *
 112 range_repr(r)
 113         rangeobject *r;
 114 {
 115         char buf[80];
 116         sprintf(buf, "(xrange(%ld, %ld, %ld) * %d)",
 117                         r->start,
 118                         r->start + r->len * r->step,
 119                         r->step,
 120                         r->reps);
 121         return PyString_FromString(buf);
 122 }
 123
 124 static PyObject *
 125 range_concat(r, obj)
 126         rangeobject *r;
 127         PyObject *obj;
 128 {
 129         PyErr_SetString(PyExc_TypeError, "cannot concatenate range objects");
 130         return NULL;
 131 }
 132
 133 static PyObject *
 134 range_repeat(r, n)
 135         rangeobject *r;
 136         int n;
 137 {
 138         if (n < 0)
 139                 return (PyObject *) PyRange_New(0, 0, 1, 1);
 140
 141         else if (n == 1) {
 142                 Py_INCREF(r);
 143                 return (PyObject *) r;
 144         }
 145
 146         else
 147                 return (PyObject *) PyRange_New(
 148                                                 r->start,
 149                                                 r->len,
 150                                                 r->step,
 151                                                 r->reps * n);
 152 }
 153
 154 static int
 155 range_compare(r1, r2)
 156         rangeobject *r1, *r2;
 157 {
 158         if (r1->start != r2->start)
 159                 return r1->start - r2->start;
 160
 161         else if (r1->step != r2->step)
 162                 return r1->step - r2->step;
 163
 164         else if (r1->len != r2->len)
 165                 return r1->len - r2->len;
 166
 167         else
 168                 return r1->reps - r2->reps;
 169 }
 170
 171 static PyObject *
 172 range_slice(r, low, high)
 173         rangeobject *r;
 174         int low, high;
 175 {
 176         if (r->reps != 1) {
 177                 PyErr_SetString(PyExc_TypeError,
 178                                 "cannot slice a replicated range");
 179                 return NULL;
 180         }
 181         if (low < 0)
 182                 low = 0;
 183         else if (low > r->len)
 184                 low = r->len;
 185         if (high < 0)
 186                 high = 0;
 187         if (high < low)
 188                 high = low;
 189         else if (high > r->len)
 190                 high = r->len;
 191
 192         if (low == 0 && high == r->len) {
 193                 Py_INCREF(r);
 194                 return (PyObject *) r;
 195         }
 196
 197         return (PyObject *) PyRange_New(
 198                                 low * r->step + r->start,
 199                                 high - low,
 200                                 r->step,
 201                                 1);
 202 }
 203
 204 static PyObject *
 205 range_tolist(self, args)
 206 rangeobject *self;
 207 PyObject *args;
 208 {
 209         PyObject *thelist;
 210         int j;
 211         int len = self->len * self->reps;
 212
 213         if (! PyArg_Parse(args, ""))
 214                 return NULL;
 215
 216         if ((thelist = PyList_New(len)) == NULL)
 217                 return NULL;
 218
 219         for (j = 0; j < len; ++j)
 220                 if ((PyList_SetItem(thelist, j, (PyObject *) PyInt_FromLong(
 221                         self->start + (j % self->len) * self->step))) < 0)
 222                         return NULL;
 223
 224         return thelist;
 225 }
 226
 227 static PyObject *
 228 range_getattr(r, name)
 229         rangeobject *r;
 230         char *name;
 231 {
 232         static PyMethodDef range_methods[] = {
 233                 {"tolist",      (PyCFunction)range_tolist},
 234                 {NULL,          NULL}
 235         };
 236
 237         return Py_FindMethod(range_methods, (PyObject *) r, name);
 238 }
 239
 240 static PySequenceMethods range_as_sequence = {
 241         (inquiry)range_length, /*sq_length*/
 242         (binaryfunc)range_concat, /*sq_concat*/
 243         (intargfunc)range_repeat, /*sq_repeat*/
 244         (intargfunc)range_item, /*sq_item*/
 245         (intintargfunc)range_slice, /*sq_slice*/
 246         0,              /*sq_ass_item*/
 247         0,              /*sq_ass_slice*/
 248 };
 249
 250 PyTypeObject PyRange_Type = {
 251         PyObject_HEAD_INIT(&PyType_Type)
 252         0,                      /* Number of items for varobject */
 253         "xrange",               /* Name of this type */
 254         sizeof(rangeobject),    /* Basic object size */
 255         0,                      /* Item size for varobject */
 256         (destructor)range_dealloc, /*tp_dealloc*/
 257         (printfunc)range_print, /*tp_print*/
 258         (getattrfunc)range_getattr, /*tp_getattr*/
 259         0,                      /*tp_setattr*/
 260         (cmpfunc)range_compare, /*tp_compare*/
 261         (reprfunc)range_repr, /*tp_repr*/
 262         0,                      /*tp_as_number*/
 263         &range_as_sequence,     /*tp_as_sequence*/
 264         0,                      /*tp_as_mapping*/
 265 };