File: antlr3rewritestreams.c

package info (click to toggle)
libantlr3c 3.4+dfsg-3
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 2,604 kB
  • sloc: ansic: 11,828; sh: 10,382; makefile: 99; cpp: 17
file content (844 lines) | stat: -rw-r--r-- 24,852 bytes parent folder | download | duplicates (4)
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
/// \file
/// Implementation of token/tree streams that are used by the
/// tree re-write rules to manipulate the tokens and trees produced
/// by rules that are subject to rewrite directives.
///

// [The "BSD licence"]
// Copyright (c) 2005-2009 Jim Idle, Temporal Wave LLC
// http://www.temporal-wave.com
// http://www.linkedin.com/in/jimidle
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
// 3. The name of the author may not be used to endorse or promote products
//    derived from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
// IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
// NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include    <antlr3rewritestreams.h>

// Static support function forward declarations for the stream types.
//
static	void				reset			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream); 
static	void				add				(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * el, void (ANTLR3_CDECL *freePtr)(void *));
static	void *				next			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	pANTLR3_BASE_TREE	nextTree		(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	void *				nextToken		(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	void *				_next			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	void *				dupTok			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * el);
static	void *				dupTree			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * el);
static	void *				dupTreeNode		(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * el);
static	pANTLR3_BASE_TREE	toTree			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * element);
static	pANTLR3_BASE_TREE	toTreeNode		(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * element);
static	ANTLR3_BOOLEAN		hasNext			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	pANTLR3_BASE_TREE	nextNode		(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	pANTLR3_BASE_TREE	nextNodeNode	(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	pANTLR3_BASE_TREE	nextNodeToken	(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	ANTLR3_UINT32		size			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	void *				getDescription	(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	void				freeRS			(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);
static	void				expungeRS		(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream);


// Place a now unused rewrite stream back on the rewrite stream pool
// so we can reuse it if we need to.
//
static void
freeRS	(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	// Before placing the stream back in the pool, we
	// need to clear any vector it has. This is so any
	// free pointers that are associated with the
	// entires are called.
	//
	if	(stream->elements != NULL)
	{
		// Factory generated vectors can be returned to the
		// vector factory for later reuse.
		//
		if	(stream->elements->factoryMade == ANTLR3_TRUE)
		{
			pANTLR3_VECTOR_FACTORY factory = ((pANTLR3_COMMON_TREE_ADAPTOR)(stream->adaptor->super))->arboretum->vFactory;
			factory->returnVector(factory, stream->elements);

			stream->elements = NULL;
		} 
		else
		{
			// Other vectors we clear and allow to be reused if they come off the
			// rewrite stream free stack and are reused.
			//
			stream->elements->clear(stream->elements);
			stream->freeElements = ANTLR3_TRUE;
		}
	}
	else
	{
		stream->freeElements = ANTLR3_FALSE; // Just in case
	}

	// Add the stream into the recognizer stream stack vector
	// adding the stream memory free routine so that
	// it is thrown away when the stack vector is destroyed
	//
	stream->rec->state->rStreams->add(stream->rec->state->rStreams, stream, (void(*)(void *))expungeRS);
}

/** Do special nilNode reuse detection for node streams.
 */
static void
freeNodeRS(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
    pANTLR3_BASE_TREE tree;

    // Before placing the stream back in the pool, we
	// need to clear any vector it has. This is so any
	// free pointers that are associated with the
	// entires are called. However, if this particular function is called
    // then we know that the entries in the stream are definately
    // tree nodes. Hence we check to see if any of them were nilNodes as
    // if they were, we can reuse them.
	//
	if	(stream->elements != NULL)
	{
        // We have some elements to traverse
        //
        ANTLR3_UINT32 i;

        for (i = 1; i<= stream->elements->count; i++)
        {
            tree = (pANTLR3_BASE_TREE)(stream->elements->elements[i-1].element);
            if  (tree != NULL && tree->isNilNode(tree))
            {
                // Had to remove this for now, check is not comprehensive enough
                // tree->reuse(tree);
            }

        }
		// Factory generated vectors can be returned to the
		// vector factory for later reuse.
		//
		if	(stream->elements->factoryMade == ANTLR3_TRUE)
		{
			pANTLR3_VECTOR_FACTORY factory = ((pANTLR3_COMMON_TREE_ADAPTOR)(stream->adaptor->super))->arboretum->vFactory;
			factory->returnVector(factory, stream->elements);

			stream->elements = NULL;
		} 
		else
		{
			stream->elements->clear(stream->elements);
			stream->freeElements = ANTLR3_TRUE;
		}
	}
	else
	{
        if  (stream->singleElement != NULL)
        {
            tree = (pANTLR3_BASE_TREE)(stream->singleElement);
            if  (tree->isNilNode(tree))
            {
                // Had to remove this for now, check is not comprehensive enough
              //   tree->reuse(tree);
            }
        }
        stream->singleElement = NULL;
		stream->freeElements = ANTLR3_FALSE; // Just in case
	}

	// Add the stream into the recognizer stream stack vector
	// adding the stream memory free routine so that
	// it is thrown away when the stack vector is destroyed
	//
	stream->rec->state->rStreams->add(stream->rec->state->rStreams, stream, (void(*)(void *))expungeRS);
}
static void
expungeRS(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{

	if (stream->freeElements == ANTLR3_TRUE && stream->elements != NULL)
	{
		stream->elements->free(stream->elements);
	}
	ANTLR3_FREE(stream);
}

// Functions for creating streams
//
static  pANTLR3_REWRITE_RULE_ELEMENT_STREAM 
antlr3RewriteRuleElementStreamNewAE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description)
{
	pANTLR3_REWRITE_RULE_ELEMENT_STREAM	stream;

	// First - do we already have a rewrite stream that was returned
	// to the pool? If we do, then we will just reuse it by resetting
	// the generic interface.
	//
	if	(rec->state->rStreams->count > 0)
	{
		// Remove the entry from the vector. We do not
		// cause it to be freed by using remove.
		//
		stream = rec->state->rStreams->remove(rec->state->rStreams, rec->state->rStreams->count - 1);

		// We found a stream we can reuse.
		// If the stream had a vector, then it will have been cleared
		// when the freeRS was called that put it in this stack
		//
	}
	else
	{
		// Ok, we need to allocate a new one as there were none on the stack.
		// First job is to create the memory we need.
		//
		stream	= (pANTLR3_REWRITE_RULE_ELEMENT_STREAM) ANTLR3_MALLOC((size_t)(sizeof(ANTLR3_REWRITE_RULE_ELEMENT_STREAM)));

		if	(stream == NULL)
		{
			return	NULL;
		}
		stream->elements		= NULL;
		stream->freeElements	= ANTLR3_FALSE;
	}

	// Populate the generic interface
	//
	stream->rec				= rec;
	stream->reset			= reset;
	stream->add				= add;
	stream->next			= next;
	stream->nextTree		= nextTree;
	stream->nextNode		= nextNode;
	stream->nextToken		= nextToken;
	stream->_next			= _next;
	stream->hasNext			= hasNext;
	stream->size			= size;
	stream->getDescription  = getDescription;
	stream->toTree			= toTree;
	stream->free			= freeRS;
	stream->singleElement	= NULL;

	// Reset the stream to empty.
	//

	stream->cursor			= 0;
	stream->dirty			= ANTLR3_FALSE;

	// Install the description
	//
	stream->elementDescription	= description;

	// Install the adaptor
	//
	stream->adaptor		= adaptor;

	return stream;
}

static pANTLR3_REWRITE_RULE_ELEMENT_STREAM 
antlr3RewriteRuleElementStreamNewAEE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, void * oneElement)
{
	pANTLR3_REWRITE_RULE_ELEMENT_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAE(adaptor, rec, description);

	if (stream == NULL)
	{
		return NULL;
	}

	// Stream seems good so we need to add the supplied element
	//
	if	(oneElement != NULL)
	{
		stream->add(stream, oneElement, NULL);
	}
	return stream;
}

static pANTLR3_REWRITE_RULE_ELEMENT_STREAM 
antlr3RewriteRuleElementStreamNewAEV(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, pANTLR3_VECTOR vector)
{
	pANTLR3_REWRITE_RULE_ELEMENT_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAE(adaptor, rec, description);

	if (stream == NULL)
	{
		return stream;
	}

	// Stream seems good so we need to install the vector we were
	// given. We assume that someone else is going to free the
	// vector.
	//
	if	(stream->elements != NULL && stream->elements->factoryMade == ANTLR3_FALSE && stream->freeElements == ANTLR3_TRUE )
	{
		stream->elements->free(stream->elements);
	}
	stream->elements		= vector;
	stream->freeElements	= ANTLR3_FALSE;
	return stream;
}

// Token rewrite stream ...
//
ANTLR3_API pANTLR3_REWRITE_RULE_TOKEN_STREAM 
antlr3RewriteRuleTOKENStreamNewAE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description)
{
	pANTLR3_REWRITE_RULE_TOKEN_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAE(adaptor, rec, description);

	if (stream == NULL)
	{
		return stream;
	}

	// Install the token based overrides
	//
	stream->dup			= dupTok;
	stream->nextNode	= nextNodeToken;

	// No nextNode implementation for a token rewrite stream
	//
	return stream;
}

ANTLR3_API pANTLR3_REWRITE_RULE_TOKEN_STREAM 
antlr3RewriteRuleTOKENStreamNewAEE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, void * oneElement)
{
	pANTLR3_REWRITE_RULE_TOKEN_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAEE(adaptor, rec, description, oneElement);

	// Install the token based overrides
	//
	stream->dup			= dupTok;
	stream->nextNode	= nextNodeToken;

	// No nextNode implementation for a token rewrite stream
	//
	return stream;
}

ANTLR3_API pANTLR3_REWRITE_RULE_TOKEN_STREAM 
antlr3RewriteRuleTOKENStreamNewAEV(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, pANTLR3_VECTOR vector)
{
	pANTLR3_REWRITE_RULE_TOKEN_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAEV(adaptor, rec, description, vector);

	// Install the token based overrides
	//
	stream->dup			= dupTok;
	stream->nextNode	= nextNodeToken;

	// No nextNode implementation for a token rewrite stream
	//
	return stream;
}

// Subtree rewrite stream
//
ANTLR3_API pANTLR3_REWRITE_RULE_SUBTREE_STREAM 
antlr3RewriteRuleSubtreeStreamNewAE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description)
{
	pANTLR3_REWRITE_RULE_SUBTREE_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAE(adaptor, rec, description);

	if (stream == NULL)
	{
		return stream;
	}

	// Install the subtree based overrides
	//
	stream->dup			= dupTree;
	stream->nextNode	= nextNode;
    stream->free        = freeNodeRS;
	return stream;

}
ANTLR3_API pANTLR3_REWRITE_RULE_SUBTREE_STREAM 
antlr3RewriteRuleSubtreeStreamNewAEE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, void * oneElement)
{
	pANTLR3_REWRITE_RULE_SUBTREE_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAEE(adaptor, rec, description, oneElement);

	if (stream == NULL)
	{
		return stream;
	}

	// Install the subtree based overrides
	//
	stream->dup			= dupTree;
	stream->nextNode	= nextNode;
    stream->free        = freeNodeRS;

	return stream;
}

ANTLR3_API pANTLR3_REWRITE_RULE_SUBTREE_STREAM 
antlr3RewriteRuleSubtreeStreamNewAEV(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, pANTLR3_VECTOR vector)
{
	pANTLR3_REWRITE_RULE_SUBTREE_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAEV(adaptor, rec, description, vector);

	if (stream == NULL)
	{
		return NULL;
	}

	// Install the subtree based overrides
	//
	stream->dup			= dupTree;
	stream->nextNode	= nextNode;
    stream->free        = freeNodeRS;

	return stream;
}
// Node rewrite stream ...
//
ANTLR3_API pANTLR3_REWRITE_RULE_NODE_STREAM 
antlr3RewriteRuleNODEStreamNewAE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description)
{
	pANTLR3_REWRITE_RULE_NODE_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAE(adaptor, rec, description);

	if (stream == NULL)
	{
		return stream;
	}

	// Install the node based overrides
	//
	stream->dup			= dupTreeNode;
	stream->toTree		= toTreeNode;
	stream->nextNode	= nextNodeNode;
    stream->free        = freeNodeRS;

	return stream;
}

ANTLR3_API pANTLR3_REWRITE_RULE_NODE_STREAM 
antlr3RewriteRuleNODEStreamNewAEE(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, void * oneElement)
{
	pANTLR3_REWRITE_RULE_NODE_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAEE(adaptor, rec, description, oneElement);

	// Install the node based overrides
	//
	stream->dup			= dupTreeNode;
	stream->toTree		= toTreeNode;
	stream->nextNode	= nextNodeNode;
    stream->free        = freeNodeRS;

	return stream;
}

ANTLR3_API pANTLR3_REWRITE_RULE_NODE_STREAM 
antlr3RewriteRuleNODEStreamNewAEV(pANTLR3_BASE_TREE_ADAPTOR adaptor, pANTLR3_BASE_RECOGNIZER rec, pANTLR3_UINT8 description, pANTLR3_VECTOR vector)
{
	pANTLR3_REWRITE_RULE_NODE_STREAM	stream;

	// First job is to create the memory we need.
	//
	stream	= antlr3RewriteRuleElementStreamNewAEV(adaptor, rec, description, vector);

	// Install the Node based overrides
	//
	stream->dup			= dupTreeNode;
	stream->toTree		= toTreeNode;
	stream->nextNode	= nextNodeNode;
    stream->free        = freeNodeRS;
    
	return stream;
}

//----------------------------------------------------------------------
// Static support functions 

/// Reset the condition of this stream so that it appears we have
/// not consumed any of its elements.  Elements themselves are untouched.
///
static void		
reset    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	stream->dirty	= ANTLR3_TRUE;
	stream->cursor	= 0;
}

// Add a new pANTLR3_BASE_TREE to this stream
//
static void		
add	    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * el, void (ANTLR3_CDECL *freePtr)(void *))
{
	if (el== NULL)
	{
		return;
	}
	// As we may be reusing a stream, we may already have allocated
	// a rewrite stream vector. If we have then is will be empty if
	// we have either zero or just one element in the rewrite stream
	//
	if (stream->elements != NULL && stream->elements->count > 0)
	{
		// We already have >1 entries in the stream. So we can just add this new element to the existing
		// collection. 
		//
		stream->elements->add(stream->elements, el, freePtr);
		return;
	}
	if (stream->singleElement == NULL)
	{
		stream->singleElement = el;
		return;
	}

	// If we got here then we had only the one element so far
	// and we must now create a vector to hold a collection of them
	//
	if	(stream->elements == NULL)
	{
        pANTLR3_VECTOR_FACTORY factory = ((pANTLR3_COMMON_TREE_ADAPTOR)(stream->adaptor->super))->arboretum->vFactory;

        
		stream->elements		= factory->newVector(factory);
		stream->freeElements	= ANTLR3_TRUE;			// We 'ummed it, so we play it son.
	}
    
	stream->elements->add	(stream->elements, stream->singleElement, freePtr);
	stream->elements->add	(stream->elements, el, freePtr);
	stream->singleElement	= NULL;

	return;
}

/// Return the next element in the stream.  If out of elements, throw
/// an exception unless size()==1.  If size is 1, then return elements[0].
/// Return a duplicate node/subtree if stream is out of elements and
/// size==1.  If we've already used the element, dup (dirty bit set).
///
static pANTLR3_BASE_TREE
nextTree(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream) 
{
	ANTLR3_UINT32		n;
	void			*  el;

	n = stream->size(stream);

	if ( stream->dirty || (stream->cursor >=n && n==1) ) 
	{
		// if out of elements and size is 1, dup
		//
		el = stream->_next(stream);
		return stream->dup(stream, el);
	}

	// test size above then fetch
	//
	el = stream->_next(stream);
	return el;
}

/// Return the next element for a caller that wants just the token
///
static	void *
nextToken		(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	return stream->_next(stream);
}

/// Return the next element in the stream.  If out of elements, throw
/// an exception unless size()==1.  If size is 1, then return elements[0].
///
static void *	
next	    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	ANTLR3_UINT32   s;

	s = stream->size(stream);
	if (stream->cursor >= s && s == 1)
	{
		pANTLR3_BASE_TREE el;

		el = stream->_next(stream);

		return	stream->dup(stream, el);
	}

	return stream->_next(stream);
}

/// Do the work of getting the next element, making sure that it's
/// a tree node or subtree.  Deal with the optimization of single-
/// element list versus list of size > 1.  Throw an exception (or something similar)
/// if the stream is empty or we're out of elements and size>1.
/// You can override in a 'subclass' if necessary.
///
static void *
_next    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	ANTLR3_UINT32		n;
	pANTLR3_BASE_TREE	t;

	n = stream->size(stream);

	if (n == 0)
	{
		// This means that the stream is empty
		//
		return NULL;	// Caller must cope with this
	}

	// Traversed all the available elements already?
	//
	if (stream->cursor >= n)
	{
		if (n == 1)
		{
			// Special case when size is single element, it will just dup a lot
			//
			return stream->toTree(stream, stream->singleElement);
		}

		// Out of elements and the size is not 1, so we cannot assume
		// that we just duplicate the entry n times (such as ID ent+ -> ^(ID ent)+)
		// This means we ran out of elements earlier than was expected.
		//
		return NULL;	// Caller must cope with this
	}

	// Elements available either for duping or just available
	//
	if (stream->singleElement != NULL)
	{
		stream->cursor++;   // Cursor advances even for single element as this tells us to dup()
		return stream->toTree(stream, stream->singleElement);
	}

	// More than just a single element so we extract it from the 
	// vector.
	//
	t = stream->toTree(stream, stream->elements->get(stream->elements, stream->cursor));
	stream->cursor++;
	return t;
}

#ifdef ANTLR3_WINDOWS
#pragma warning(push)
#pragma warning(disable : 4100)
#endif
/// When constructing trees, sometimes we need to dup a token or AST
/// subtree.  Dup'ing a token means just creating another AST node
/// around it.  For trees, you must call the adaptor.dupTree().
///
static void *	
dupTok	    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * el)
{
	ANTLR3_FPRINTF(stderr, "dup() cannot be called on a token rewrite stream!!");
	return NULL;
}
#ifdef ANTLR3_WINDOWS
#pragma warning(pop)
#endif

/// When constructing trees, sometimes we need to dup a token or AST
/// subtree.  Dup'ing a token means just creating another AST node
/// around it.  For trees, you must call the adaptor.dupTree().
///
static void *	
dupTree	    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * element)
{
	return stream->adaptor->dupNode(stream->adaptor, (pANTLR3_BASE_TREE)element);
}

#ifdef ANTLR3_WINDOWS
#pragma warning(push)
#pragma warning(disable : 4100)
#endif
/// When constructing trees, sometimes we need to dup a token or AST
/// subtree.  Dup'ing a token means just creating another AST node
/// around it.  For trees, you must call the adaptor.dupTree().
///
static void *	
dupTreeNode	    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * element)
{
	ANTLR3_FPRINTF(stderr, "dup() cannot be called on a node rewrite stream!!!");
	return NULL;
}


/// We don;t explicitly convert to a tree unless the call goes to 
/// nextTree, which means rewrites are heterogeneous 
///
static pANTLR3_BASE_TREE	
toTree   (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * element)
{
	return (pANTLR3_BASE_TREE)element;
}
#ifdef ANTLR3_WINDOWS
#pragma warning(pop)
#endif

/// Ensure stream emits trees; tokens must be converted to AST nodes.
/// AST nodes can be passed through unmolested.
///
#ifdef ANTLR3_WINDOWS
#pragma warning(push)
#pragma warning(disable : 4100)
#endif

static pANTLR3_BASE_TREE	
toTreeNode   (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream, void * element)
{
	return stream->adaptor->dupNode(stream->adaptor, (pANTLR3_BASE_TREE)element);
}

#ifdef ANTLR3_WINDOWS
#pragma warning(pop)
#endif

/// Returns ANTLR3_TRUE if there is a next element available
///
static ANTLR3_BOOLEAN	
hasNext  (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	if (	(stream->singleElement != NULL && stream->cursor < 1)
		||	(stream->elements != NULL && stream->cursor < stream->elements->size(stream->elements)))
	{
		return ANTLR3_TRUE;
	}
	else
	{
		return ANTLR3_FALSE;
	}
}

/// Get the next token from the list and create a node for it
/// This is the implementation for token streams.
///
static pANTLR3_BASE_TREE
nextNodeToken(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	return stream->adaptor->create(stream->adaptor, stream->_next(stream));
}

static pANTLR3_BASE_TREE
nextNodeNode(pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	return stream->_next(stream);
}

/// Treat next element as a single node even if it's a subtree.
/// This is used instead of next() when the result has to be a
/// tree root node.  Also prevents us from duplicating recently-added
/// children; e.g., ^(type ID)+ adds ID to type and then 2nd iteration
/// must dup the type node, but ID has been added.
///
/// Referencing to a rule result twice is ok; dup entire tree as
/// we can't be adding trees; e.g., expr expr. 
///
static pANTLR3_BASE_TREE	
nextNode (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{

	ANTLR3_UINT32	n;
	pANTLR3_BASE_TREE	el = stream->_next(stream);

	n = stream->size(stream);
	if (stream->dirty == ANTLR3_TRUE || (stream->cursor > n && n == 1))
	{
		// We are out of elements and the size is 1, which means we just 
		// dup the node that we have
		//
		return	stream->adaptor->dupNode(stream->adaptor, el);
	}

	// We were not out of nodes, so the one we received is the one to return
	//
	return  el;
}

/// Number of elements available in the stream
///
static ANTLR3_UINT32	
size	    (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	ANTLR3_UINT32   n = 0;

	/// Should be a count of one if singleElement is set. I copied this
	/// logic from the java implementation, which I suspect is just guarding
	/// against someone setting singleElement and forgetting to NULL it out
	///
	if (stream->singleElement != NULL)
	{
		n = 1;
	}
	else
	{
		if (stream->elements != NULL)
		{
			return (ANTLR3_UINT32)(stream->elements->count);
		}
	}
	return n;
}

/// Returns the description string if there is one available (check for NULL).
///
static void *	
getDescription  (pANTLR3_REWRITE_RULE_ELEMENT_STREAM stream)
{
	if (stream->elementDescription == NULL)
	{
		stream->elementDescription = "<unknown source>";
	}

	return  stream->elementDescription;
}