summaryrefslogtreecommitdiff
path: root/Include/abstract.h
blob: 70c0e7cf31688c038a8c632c15281e1fbbd139ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
#ifndef Py_ABSTRACTOBJECT_H
#define Py_ABSTRACTOBJECT_H
#ifdef __cplusplus
extern "C" {
#endif

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI or Corporation for National Research Initiatives or
CNRI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.

While CWI is the initial source for this software, a modified version
is made available by the Corporation for National Research Initiatives
(CNRI) at the Internet address ftp://ftp.python.org.

STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

/* Abstract Object Interface (many thanks to Jim Fulton) */

/*
   PROPOSAL: A Generic Python Object Interface for Python C Modules

Problem

  Python modules written in C that must access Python objects must do
  so through routines whose interfaces are described by a set of
  include files.  Unfortunately, these routines vary according to the
  object accessed.  To use these routines, the C programmer must check
  the type of the object being used and must call a routine based on
  the object type.  For example, to access an element of a sequence,
  the programmer must determine whether the sequence is a list or a
  tuple:

    if(is_tupleobject(o))
      e=gettupleitem(o,i)
    else if(is_listitem(o))
      e=getlistitem(o,i)

  If the programmer wants to get an item from another type of object
  that provides sequence behavior, there is no clear way to do it
  correctly.  

  The persistent programmer may peruse object.h and find that the
  _typeobject structure provides a means of invoking up to (currently
  about) 41 special operators.  So, for example, a routine can get an
  item from any object that provides sequence behavior. However, to
  use this mechanism, the programmer must make their code dependent on
  the current Python implementation.

  Also, certain semantics, especially memory management semantics, may
  differ by the type of object being used.  Unfortunately, these
  semantics are not clearly described in the current include files.
  An abstract interface providing more consistent semantics is needed. 

Proposal

  I propose the creation of a standard interface (with an associated
  library of routines and/or macros) for generically obtaining the
  services of Python objects.  This proposal can be viewed as one
  components of a Python C interface consisting of several components.

  From the viewpoint of of C access to Python services, we have (as
  suggested by Guido in off-line discussions):

  - "Very high level layer": two or three functions that let you exec or
    eval arbitrary Python code given as a string in a module whose name is
    given, passing C values in and getting C values out using
    mkvalue/getargs style format strings.  This does not require the user
    to declare any variables of type "PyObject *".  This should be enough
    to write a simple application that gets Python code from the user,
    execs it, and returns the output or errors.  (Error handling must also
    be part of this API.)

  - "Abstract objects layer": which is the subject of this proposal.
    It has many functions operating on objects, and lest you do many
    things from C that you can also write in Python, without going
    through the Python parser.

  - "Concrete objects layer": This is the public type-dependent
    interface provided by the standard built-in types, such as floats,
    strings, and lists.  This interface exists and is currently
    documented by the collection of include files provides with the
    Python distributions.

  From the point of view of Python accessing services provided by C
  modules: 

  - "Python module interface": this interface consist of the basic
    routines used to define modules and their members.  Most of the
    current extensions-writing guide deals with this interface.

  - "Built-in object interface": this is the interface that a new
    built-in type must provide and the mechanisms and rules that a
    developer of a new built-in type must use and follow.

  This proposal is a "first-cut" that is intended to spur
  discussion. See especially the lists of notes.

  The Python C object interface will provide four protocols: object,
  numeric, sequence, and mapping.  Each protocol consists of a
  collection of related operations.  If an operation that is not
  provided by a particular type is invoked, then a standard exception,
  NotImplementedError is raised with a operation name as an argument.
  In addition, for convenience this interface defines a set of
  constructors for building objects of built-in types.  This is needed
  so new objects can be returned from C functions that otherwise treat
  objects generically.

Memory Management

  For all of the functions described in this proposal, if a function
  retains a reference to a Python object passed as an argument, then the
  function will increase the reference count of the object.  It is
  unnecessary for the caller to increase the reference count of an
  argument in anticipation of the object's retention.

  All Python objects returned from functions should be treated as new
  objects.  Functions that return objects assume that the caller will
  retain a reference and the reference count of the object has already
  been incremented to account for this fact.  A caller that does not
  retain a reference to an object that is returned from a function
  must decrement the reference count of the object (using
  DECREF(object)) to prevent memory leaks.

  Note that the behavior mentioned here is different from the current
  behavior for some objects (e.g. lists and tuples) when certain
  type-specific routines are called directly (e.g. setlistitem).  The
  proposed abstraction layer will provide a consistent memory
  management interface, correcting for inconsistent behavior for some
  built-in types.

Protocols

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/

/*  Object Protocol: */

     /* Implemented elsewhere:

     int PyObject_Print(PyObject *o, FILE *fp, int flags);

         Print an object, o, on file, fp.  Returns -1 on
	 error.  The flags argument is used to enable certain printing
	 options. The only option currently supported is Py_Print_RAW. 

         (What should be said about Py_Print_RAW?)	

       */

     /* Implemented elsewhere:

     int PyObject_HasAttrString(PyObject *o, char *attr_name);

         Returns 1 if o has the attribute attr_name, and 0 otherwise.
	 This is equivalent to the Python expression:
	 hasattr(o,attr_name). 

	 This function always succeeds.

       */

     /* Implemented elsewhere:

     PyObject* PyObject_GetAttrString(PyObject *o, char *attr_name);

	 Retrieve an attributed named attr_name form object o.
	 Returns the attribute value on success, or NULL on failure.
	 This is the equivalent of the Python expression: o.attr_name.

       */

     /* Implemented elsewhere:

     int PyObject_HasAttr(PyObject *o, PyObject *attr_name);

         Returns 1 if o has the attribute attr_name, and 0 otherwise.
	 This is equivalent to the Python expression:
	 hasattr(o,attr_name). 

	 This function always succeeds.

       */

     /* Implemented elsewhere:

     PyObject* PyObject_GetAttr(PyObject *o, PyObject *attr_name);

	 Retrieve an attributed named attr_name form object o.
	 Returns the attribute value on success, or NULL on failure.
	 This is the equivalent of the Python expression: o.attr_name.

       */


     /* Implemented elsewhere:

     int PyObject_SetAttrString(PyObject *o, char *attr_name, PyObject *v);

	 Set the value of the attribute named attr_name, for object o,
	 to the value, v. Returns -1 on failure.  This is
	 the equivalent of the Python statement: o.attr_name=v.

       */

     /* Implemented elsewhere:

     int PyObject_SetAttr(PyObject *o, PyObject *attr_name, PyObject *v);

	 Set the value of the attribute named attr_name, for object o,
	 to the value, v. Returns -1 on failure.  This is
	 the equivalent of the Python statement: o.attr_name=v.

       */

     /* implemented as a macro:

     int PyObject_DelAttrString(PyObject *o, char *attr_name);

	 Delete attribute named attr_name, for object o. Returns
	 -1 on failure.  This is the equivalent of the Python
	 statement: del o.attr_name.

       */
#define  PyObject_DelAttrString(O,A) PyObject_SetAttrString((O),(A),NULL)

     /* implemented as a macro:

     int PyObject_DelAttr(PyObject *o, PyObject *attr_name);

	 Delete attribute named attr_name, for object o. Returns -1
	 on failure.  This is the equivalent of the Python
	 statement: del o.attr_name.

       */
#define  PyObject_DelAttr(O,A) PyObject_SetAttr((O),(A),NULL)

     DL_IMPORT(int) PyObject_Cmp Py_PROTO((PyObject *o1, PyObject *o2, int *result));

       /*
	 Compare the values of o1 and o2 using a routine provided by
	 o1, if one exists, otherwise with a routine provided by o2.
	 The result of the comparison is returned in result.  Returns
	 -1 on failure.  This is the equivalent of the Python
	 statement: result=cmp(o1,o2).

       */

     /* Implemented elsewhere:

     int PyObject_Compare(PyObject *o1, PyObject *o2);

	 Compare the values of o1 and o2 using a routine provided by
	 o1, if one exists, otherwise with a routine provided by o2.
	 Returns the result of the comparison on success.  On error,
	 the value returned is undefined. This is equivalent to the
	 Python expression: cmp(o1,o2).

       */

     /* Implemented elsewhere:

     PyObject *PyObject_Repr(PyObject *o);

	 Compute the string representation of object, o.  Returns the
	 string representation on success, NULL on failure.  This is
	 the equivalent of the Python expression: repr(o).

	 Called by the repr() built-in function and by reverse quotes.

       */

     /* Implemented elsewhere:

     PyObject *PyObject_Str(PyObject *o);

	 Compute the string representation of object, o.  Returns the
	 string representation on success, NULL on failure.  This is
	 the equivalent of the Python expression: str(o).)

	 Called by the str() built-in function and by the print
	 statement.

       */

     DL_IMPORT(int) PyCallable_Check Py_PROTO((PyObject *o));

       /*
	 Determine if the object, o, is callable.  Return 1 if the
	 object is callable and 0 otherwise.

	 This function always succeeds.

       */


     
     DL_IMPORT(PyObject *) PyObject_CallObject Py_PROTO((PyObject *callable_object,
					     PyObject *args));

       /*

	 Call a callable Python object, callable_object, with
	 arguments given by the tuple, args.  If no arguments are
	 needed, then args may be NULL.  Returns the result of the
	 call on success, or NULL on failure.  This is the equivalent
	 of the Python expression: apply(o,args).

       */

     DL_IMPORT(PyObject *) PyObject_CallFunction Py_PROTO((PyObject *callable_object,
					       char *format, ...));

       /*
	 Call a callable Python object, callable_object, with a
	 variable number of C arguments. The C arguments are described
	 using a mkvalue-style format string. The format may be NULL,
	 indicating that no arguments are provided.  Returns the
	 result of the call on success, or NULL on failure.  This is
	 the equivalent of the Python expression: apply(o,args).

       */


     DL_IMPORT(PyObject *) PyObject_CallMethod Py_PROTO((PyObject *o, char *m,
					     char *format, ...));

       /*
	 Call the method named m of object o with a variable number of
	 C arguments.  The C arguments are described by a mkvalue
	 format string.  The format may be NULL, indicating that no
	 arguments are provided. Returns the result of the call on
	 success, or NULL on failure.  This is the equivalent of the
	 Python expression: o.method(args).

         Note that Special method names, such as "__add__",
	 "__getitem__", and so on are not supported. The specific
	 abstract-object routines for these must be used.

       */


     /* Implemented elsewhere:

     long PyObject_Hash(PyObject *o);

         Compute and return the hash, hash_value, of an object, o.  On
	 failure, return -1.  This is the equivalent of the Python
	 expression: hash(o).

       */


     /* Implemented elsewhere:

     int PyObject_IsTrue(PyObject *o);

	 Returns 1 if the object, o, is considered to be true, and
	 0 otherwise. This is equivalent to the Python expression:
	 not not o

	 This function always succeeds.
	 
       */

     /* Implemented elsewhere:

     int PyObject_Not(PyObject *o);

	 Returns 0 if the object, o, is considered to be true, and
	 1 otherwise. This is equivalent to the Python expression:
	 not o

	 This function always succeeds.
	 
       */

     DL_IMPORT(PyObject *) PyObject_Type Py_PROTO((PyObject *o));

       /*
	 On success, returns a type object corresponding to the object
	 type of object o. On failure, returns NULL.  This is
	 equivalent to the Python expression: type(o).
       */

     DL_IMPORT(int) PyObject_Length Py_PROTO((PyObject *o));

       /*
         Return the length of object o.  If the object, o, provides
	 both sequence and mapping protocols, the sequence length is
	 returned. On error, -1 is returned.  This is the equivalent
	 to the Python expression: len(o).

       */

     DL_IMPORT(PyObject *) PyObject_GetItem Py_PROTO((PyObject *o, PyObject *key));

       /*
	 Return element of o corresponding to the object, key, or NULL
	 on failure. This is the equivalent of the Python expression:
	 o[key].

       */

     DL_IMPORT(int) PyObject_SetItem Py_PROTO((PyObject *o, PyObject *key, PyObject *v));

       /*
	 Map the object, key, to the value, v.  Returns
	 -1 on failure.  This is the equivalent of the Python
	 statement: o[key]=v.
       */

     DL_IMPORT(int) PyObject_DelItem Py_PROTO((PyObject *o, PyObject *key));

       /*
	 Delete the mapping for key from *o.  Returns -1 on failure.
	 This is the equivalent of the Python statement: del o[key].
       */

     DL_IMPORT(int) PyObject_AsCharBuffer(PyObject *obj,
					  const char **buffer,
					  int *buffer_len);

       /* 
	  Takes an arbitrary object which must support the (character,
	  single segment) buffer interface and returns a pointer to a
	  read-only memory location useable as character based input
	  for subsequent processing.

	  0 is returned on success.  buffer and buffer_len are only
	  set in case no error occurrs. Otherwise, -1 is returned and
	  an exception set.

       */

     DL_IMPORT(int) PyObject_AsReadBuffer(PyObject *obj,
					  const void **buffer,
					  int *buffer_len);

       /* 
	  Same as PyObject_AsCharBuffer() except that this API expects
	  (readable, single segment) buffer interface and returns a
	  pointer to a read-only memory location which can contain
	  arbitrary data.

	  0 is returned on success.  buffer and buffer_len are only
	  set in case no error occurrs.  Otherwise, -1 is returned and
	  an exception set.

       */

     DL_IMPORT(int) PyObject_AsWriteBuffer(PyObject *obj,
					   void **buffer,
					   int *buffer_len);

       /* 
	  Takes an arbitrary object which must support the (writeable,
	  single segment) buffer interface and returns a pointer to a
	  writeable memory location in buffer of size buffer_len.

	  0 is returned on success.  buffer and buffer_len are only
	  set in case no error occurrs. Otherwise, -1 is returned and
	  an exception set.

       */

/*  Number Protocol:*/

     DL_IMPORT(int) PyNumber_Check Py_PROTO((PyObject *o));

       /*
         Returns 1 if the object, o, provides numeric protocols, and
	 false otherwise. 

	 This function always succeeds.

       */

     DL_IMPORT(PyObject *) PyNumber_Add Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of adding o1 and o2, or null on failure.
	 This is the equivalent of the Python expression: o1+o2.


       */

     DL_IMPORT(PyObject *) PyNumber_Subtract Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of subtracting o2 from o1, or null on
	 failure.  This is the equivalent of the Python expression:
	 o1-o2.

       */

     DL_IMPORT(PyObject *) PyNumber_Multiply Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of multiplying o1 and o2, or null on
	 failure.  This is the equivalent of the Python expression:
	 o1*o2.


       */

     DL_IMPORT(PyObject *) PyNumber_Divide Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of dividing o1 by o2, or null on failure.
	 This is the equivalent of the Python expression: o1/o2.


       */

     DL_IMPORT(PyObject *) PyNumber_Remainder Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the remainder of dividing o1 by o2, or null on
	 failure.  This is the equivalent of the Python expression:
	 o1%o2.


       */

     DL_IMPORT(PyObject *) PyNumber_Divmod Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 See the built-in function divmod.  Returns NULL on failure.
	 This is the equivalent of the Python expression:
	 divmod(o1,o2).


       */

     DL_IMPORT(PyObject *) PyNumber_Power Py_PROTO((PyObject *o1, PyObject *o2, PyObject *o3));

       /*
	 See the built-in function pow.  Returns NULL on failure.
	 This is the equivalent of the Python expression:
	 pow(o1,o2,o3), where o3 is optional.

       */

     DL_IMPORT(PyObject *) PyNumber_Negative Py_PROTO((PyObject *o));

       /*
	 Returns the negation of o on success, or null on failure.
	 This is the equivalent of the Python expression: -o.

       */

     DL_IMPORT(PyObject *) PyNumber_Positive Py_PROTO((PyObject *o));

       /*
         Returns the (what?) of o on success, or NULL on failure.
	 This is the equivalent of the Python expression: +o.

       */

     DL_IMPORT(PyObject *) PyNumber_Absolute Py_PROTO((PyObject *o));

       /*
	 Returns the absolute value of o, or null on failure.  This is
	 the equivalent of the Python expression: abs(o).

       */

     DL_IMPORT(PyObject *) PyNumber_Invert Py_PROTO((PyObject *o));

       /*
	 Returns the bitwise negation of o on success, or NULL on
	 failure.  This is the equivalent of the Python expression:
	 ~o.


       */

     DL_IMPORT(PyObject *) PyNumber_Lshift Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of left shifting o1 by o2 on success, or
	 NULL on failure.  This is the equivalent of the Python
	 expression: o1 << o2.


       */

     DL_IMPORT(PyObject *) PyNumber_Rshift Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of right shifting o1 by o2 on success, or
	 NULL on failure.  This is the equivalent of the Python
	 expression: o1 >> o2.

       */

     DL_IMPORT(PyObject *) PyNumber_And Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of bitwise and of o1 and o2 on success, or
	 NULL on failure. This is the equivalent of the Python
	 expression: o1&o2.


       */

     DL_IMPORT(PyObject *) PyNumber_Xor Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the bitwise exclusive or of o1 by o2 on success, or
	 NULL on failure.  This is the equivalent of the Python
	 expression: o1^o2.


       */

     DL_IMPORT(PyObject *) PyNumber_Or Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Returns the result of bitwise or or o1 and o2 on success, or
	 NULL on failure.  This is the equivalent of the Python
	 expression: o1|o2.

       */

     /* Implemented elsewhere:

     int PyNumber_Coerce(PyObject **p1, PyObject **p2);

	 This function takes the addresses of two variables of type
	 PyObject*.

	 If the objects pointed to by *p1 and *p2 have the same type,
	 increment their reference count and return 0 (success).
	 If the objects can be converted to a common numeric type,
	 replace *p1 and *p2 by their converted value (with 'new'
	 reference counts), and return 0.
	 If no conversion is possible, or if some other error occurs,
	 return -1 (failure) and don't increment the reference counts.
	 The call PyNumber_Coerce(&o1, &o2) is equivalent to the Python
	 statement o1, o2 = coerce(o1, o2).

       */

     DL_IMPORT(PyObject *) PyNumber_Int Py_PROTO((PyObject *o));

       /*
	 Returns the o converted to an integer object on success, or
	 NULL on failure.  This is the equivalent of the Python
	 expression: int(o).

       */

     DL_IMPORT(PyObject *) PyNumber_Long Py_PROTO((PyObject *o));

       /*
	 Returns the o converted to a long integer object on success,
	 or NULL on failure.  This is the equivalent of the Python
	 expression: long(o).

       */

     DL_IMPORT(PyObject *) PyNumber_Float Py_PROTO((PyObject *o));

       /*
	 Returns the o converted to a float object on success, or NULL
	 on failure.  This is the equivalent of the Python expression:
	 float(o).
       */
	 

/*  Sequence protocol:*/

     DL_IMPORT(int) PySequence_Check Py_PROTO((PyObject *o));

       /*
         Return 1 if the object provides sequence protocol, and zero
	 otherwise.  

	 This function always succeeds.

       */

     DL_IMPORT(int) PySequence_Length Py_PROTO((PyObject *o));

       /*
         Return the length of sequence object o, or -1 on failure.

       */

     DL_IMPORT(PyObject *) PySequence_Concat Py_PROTO((PyObject *o1, PyObject *o2));

       /*
	 Return the concatination of o1 and o2 on success, and NULL on
	 failure.   This is the equivalent of the Python
	 expression: o1+o2.

       */

     DL_IMPORT(PyObject *) PySequence_Repeat Py_PROTO((PyObject *o, int count));

       /*
	 Return the result of repeating sequence object o count times,
	 or NULL on failure.  This is the equivalent of the Python
	 expression: o1*count.

       */

     DL_IMPORT(PyObject *) PySequence_GetItem Py_PROTO((PyObject *o, int i));

       /*
	 Return the ith element of o, or NULL on failure. This is the
	 equivalent of the Python expression: o[i].
       */

     DL_IMPORT(PyObject *) PySequence_GetSlice Py_PROTO((PyObject *o, int i1, int i2));

       /*
	 Return the slice of sequence object o between i1 and i2, or
	 NULL on failure. This is the equivalent of the Python
	 expression: o[i1:i2].

       */

     DL_IMPORT(int) PySequence_SetItem Py_PROTO((PyObject *o, int i, PyObject *v));

       /*
	 Assign object v to the ith element of o.  Returns
	 -1 on failure.  This is the equivalent of the Python
	 statement: o[i]=v.

       */

     DL_IMPORT(int) PySequence_DelItem Py_PROTO((PyObject *o, int i));

       /*
	 Delete the ith element of object v.  Returns
	 -1 on failure.  This is the equivalent of the Python
	 statement: del o[i].
       */

     DL_IMPORT(int) PySequence_SetSlice Py_PROTO((PyObject *o, int i1, int i2, PyObject *v));

       /*
         Assign the sequence object, v, to the slice in sequence
	 object, o, from i1 to i2.  Returns -1 on failure. This is the
	 equivalent of the Python statement: o[i1:i2]=v.
       */

     DL_IMPORT(int) PySequence_DelSlice Py_PROTO((PyObject *o, int i1, int i2));

       /*
	 Delete the slice in sequence object, o, from i1 to i2.
	 Returns -1 on failure. This is the equivalent of the Python
	 statement: del o[i1:i2].
       */

     DL_IMPORT(PyObject *) PySequence_Tuple Py_PROTO((PyObject *o));

       /*
	 Returns the sequence, o, as a tuple on success, and NULL on failure.
	 This is equivalent to the Python expression: tuple(o)
       */


     DL_IMPORT(PyObject *) PySequence_List Py_PROTO((PyObject *o));

       /*
	 Returns the sequence, o, as a list on success, and NULL on failure.
	 This is equivalent to the Python expression: list(o)
       */

     DL_IMPORT(PyObject *) PySequence_Fast Py_PROTO((PyObject *o, const char* m));

       /*
         Returns the sequence, o, as a tuple, unless it's already a
         tuple or list.  Use PySequence_Fast_GET_ITEM to access the
         members of this list.

         Returns NULL on failure.  If the object is not a sequence,
         raises a TypeError exception with m as the message text.
       */

#define PySequence_Fast_GET_ITEM(o, i)\
     (PyList_Check(o) ? PyList_GET_ITEM(o, i) : PyTuple_GET_ITEM(o, i))

       /*
	 Return the ith element of o, assuming that o was returned by
         PySequence_Fast, and that i is within bounds.
       */

     DL_IMPORT(int) PySequence_Count Py_PROTO((PyObject *o, PyObject *value));

       /*
         Return the number of occurrences on value on o, that is,
	 return the number of keys for which o[key]==value.  On
	 failure, return -1.  This is equivalent to the Python
	 expression: o.count(value).
       */

     DL_IMPORT(int) PySequence_Contains Py_PROTO((PyObject *o, PyObject *value));

/* For DLL-level backwards compatibility */
#undef PySequence_In
     DL_IMPORT(int) PySequence_In Py_PROTO((PyObject *o, PyObject *value));

/* For source-level backwards compatibility */
#define PySequence_In PySequence_Contains

       /*
	 Determine if o contains value.  If an item in o is equal to
	 X, return 1, otherwise return 0.  On error, return -1.  This
	 is equivalent to the Python expression: value in o.
       */

     DL_IMPORT(int) PySequence_Index Py_PROTO((PyObject *o, PyObject *value));

       /*
	 Return the first index for which o[i]=value.  On error,
	 return -1.    This is equivalent to the Python
	 expression: o.index(value).
       */

/*  Mapping protocol:*/

     DL_IMPORT(int) PyMapping_Check Py_PROTO((PyObject *o));

       /*
         Return 1 if the object provides mapping protocol, and zero
	 otherwise.  

	 This function always succeeds.
       */

     DL_IMPORT(int) PyMapping_Length Py_PROTO((PyObject *o));

       /*
         Returns the number of keys in object o on success, and -1 on
	 failure.  For objects that do not provide sequence protocol,
	 this is equivalent to the Python expression: len(o).
       */

     /* implemented as a macro:

     int PyMapping_DelItemString Py_PROTO((PyObject *o, char *key));

	 Remove the mapping for object, key, from the object *o.
	 Returns -1 on failure.  This is equivalent to
	 the Python statement: del o[key].
       */
#define PyMapping_DelItemString(O,K) PyDict_DelItemString((O),(K))

     /* implemented as a macro:

     int PyMapping_DelItem Py_PROTO((PyObject *o, PyObject *key));

	 Remove the mapping for object, key, from the object *o.
	 Returns -1 on failure.  This is equivalent to
	 the Python statement: del o[key].
       */
#define PyMapping_DelItem(O,K) PyDict_DelItem((O),(K))

     DL_IMPORT(int) PyMapping_HasKeyString Py_PROTO((PyObject *o, char *key));

       /*
	 On success, return 1 if the mapping object has the key, key,
	 and 0 otherwise.  This is equivalent to the Python expression:
	 o.has_key(key). 

	 This function always succeeds.
       */

     DL_IMPORT(int) PyMapping_HasKey Py_PROTO((PyObject *o, PyObject *key));

       /*
	 Return 1 if the mapping object has the key, key,
	 and 0 otherwise.  This is equivalent to the Python expression:
	 o.has_key(key). 

	 This function always succeeds.

       */

     /* Implemented as macro:

     PyObject *PyMapping_Keys(PyObject *o);

         On success, return a list of the keys in object o.  On
	 failure, return NULL. This is equivalent to the Python
	 expression: o.keys().
       */
#define PyMapping_Keys(O) PyObject_CallMethod(O,"keys",NULL)

     /* Implemented as macro:

     PyObject *PyMapping_Values(PyObject *o);

         On success, return a list of the values in object o.  On
	 failure, return NULL. This is equivalent to the Python
	 expression: o.values().
       */
#define PyMapping_Values(O) PyObject_CallMethod(O,"values",NULL)

     /* Implemented as macro:

     PyObject *PyMapping_Items(PyObject *o);

         On success, return a list of the items in object o, where
	 each item is a tuple containing a key-value pair.  On
	 failure, return NULL. This is equivalent to the Python
	 expression: o.items().

       */
#define PyMapping_Items(O) PyObject_CallMethod(O,"items",NULL)

     DL_IMPORT(PyObject *) PyMapping_GetItemString Py_PROTO((PyObject *o, char *key));

       /*
	 Return element of o corresponding to the object, key, or NULL
	 on failure. This is the equivalent of the Python expression:
	 o[key].
       */

     DL_IMPORT(int) PyMapping_SetItemString Py_PROTO((PyObject *o, char *key,
					   PyObject *value));

       /*
	 Map the object, key, to the value, v.  Returns 
	 -1 on failure.  This is the equivalent of the Python
	 statement: o[key]=v.
      */


#ifdef __cplusplus
}
#endif
#endif /* Py_ABSTRACTOBJECT_H */