This file is indexed.

/usr/share/gnu-smalltalk/kernel/Object.st is in gnu-smalltalk-common 3.2.4-2.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   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
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
"======================================================================
|
|   Object Method Definitions
|
|
 ======================================================================"

"======================================================================
|
| Copyright 1990,1991,1992,94,95,99,2000,2001,2002,2003,2007,2008,2009
| Free Software Foundation, Inc.
| Written by Steve Byrne.
|
| This file is part of the GNU Smalltalk class library.
|
| The GNU Smalltalk class library is free software; you can redistribute it
| and/or modify it under the terms of the GNU Lesser General Public License
| as published by the Free Software Foundation; either version 2.1, or (at
| your option) any later version.
| 
| The GNU Smalltalk class library is distributed in the hope that it will be
| useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser
| General Public License for more details.
| 
| You should have received a copy of the GNU Lesser General Public License
| along with the GNU Smalltalk class library; see the file COPYING.LIB.
| If not, write to the Free Software Foundation, 59 Temple Place - Suite
| 330, Boston, MA 02110-1301, USA.  
|
 ======================================================================"



nil subclass: Object [
    
    <comment: 'I am the root of the Smalltalk class system. 
All classes in the system are subclasses of me.'>
    <category: 'Language-Implementation'>

    Dependencies := nil.
    FinalizableObjects := nil.

    Object class >> update: aspect [
	"Do any global tasks for the ObjectMemory events."

	<category: 'initialization'>
	aspect == #returnFromSnapshot ifFalse: [^self].
	ContextPart checkPresenceOfJIT.
	FinalizableObjects := nil
    ]

    Object class >> dependencies [
	"Answer a dictionary that associates an object with its dependents."

	<category: 'initialization'>
	^Dependencies
    ]

    Object class >> dependencies: anObject [
	"Use anObject as the dictionary that associates an object with its dependents."

	<category: 'initialization'>
	Dependencies := anObject
    ]

    Object class >> finalizableObjects [
	"Answer a set of finalizable objects."

	<category: 'initialization'>
	FinalizableObjects isNil ifTrue: [FinalizableObjects := Set new].
	^FinalizableObjects
    ]

    Object class >> initialize [
	"Initialize the Dependencies dictionary to be a WeakKeyIdentityDictionary."

	<category: 'initialization'>
	self == Object ifFalse: [^self].
	self dependencies: WeakKeyIdentityDictionary new.
	ObjectMemory addDependent: self
    ]

    ~= anObject [
	"Answer whether the receiver and anObject are not equal"

	<category: 'relational operators'>
	^self = anObject == false
    ]

    ~~ anObject [
	"Answer whether the receiver and anObject are not the same object"

	<category: 'relational operators'>
	^self == anObject == false
    ]

    isKindOf: aClass [
	"Answer whether the receiver's class is aClass or
	 a subclass of aClass"

	<category: 'testing functionality'>
	^self class == aClass or: [self class inheritsFrom: aClass]
    ]

    isMemberOf: aClass [
	"Returns true if the receiver is an instance of the class 'aClass'"

	<category: 'testing functionality'>
	^self class == aClass
    ]

    respondsTo: aSymbol [
	"Returns true if the receiver understands the given selector"

	<category: 'testing functionality'>
	^self class canUnderstand: aSymbol
    ]

    isNil [
	"Answer whether the receiver is nil"

	<category: 'testing functionality'>
	^false
    ]

    notNil [
	"Answer whether the receiver is not nil"

	<category: 'testing functionality'>
	^true
    ]

    ifNil: nilBlock [
	"Evaluate nilBlock if the receiver is nil, else answer self"

	<category: 'testing functionality'>
	^self
    ]

    ifNil: nilBlock ifNotNil: notNilBlock [
	"Evaluate nilBlock if the receiver is nil, else evaluate
	 notNilBlock, passing the receiver."

	<category: 'testing functionality'>
	^notNilBlock cull: self
    ]

    ifNotNil: notNilBlock [
	"Evaluate notNilBlock if the receiver is not nil, passing the receiver.
	 Else answer nil."

	<category: 'testing functionality'>
	^notNilBlock cull: self
    ]

    ifNotNil: notNilBlock ifNil: nilBlock [
	"Evaluate nilBlock if the receiver is nil, else evaluate
	 notNilBlock, passing the receiver."

	<category: 'testing functionality'>
	^notNilBlock cull: self
    ]

    isCObject [
	<category: 'testing functionality'>
	^false
    ]

    isString [
	<category: 'testing functionality'>
	^false
    ]

    isCharacterArray [
	<category: 'testing functionality'>
	^false
    ]

    isSymbol [
	<category: 'testing functionality'>
	^false
    ]

    isCharacter [
	<category: 'testing functionality'>
	^false
    ]

    isNumber [
	<category: 'testing functionality'>
	^false
    ]

    isFloat [
	<category: 'testing functionality'>
	^false
    ]

    isInteger [
	<category: 'testing functionality'>
	^false
    ]

    isSmallInteger [
	<category: 'testing functionality'>
	^false
    ]

    isNamespace [
	<category: 'testing functionality'>
	^false
    ]

    isClass [
	<category: 'testing functionality'>
	^false
    ]

    isArray [
	<category: 'testing functionality'>
	^false
    ]

    isBehavior [
	<category: 'testing functionality'>
	^false
    ]

    isMeta [
	"Same as isMetaclass"

	<category: 'testing functionality'>
	^self isMetaclass
    ]

    isMetaClass [
	"Same as isMetaclass"

	<category: 'testing functionality'>
	^self isMetaclass
    ]

    isMetaclass [
	<category: 'testing functionality'>
	^false
    ]

    copy [
	"Returns a shallow copy of the receiver (the instance variables are
	 not copied). The shallow copy receives the message postCopy and the
	 result of postCopy is passed back."

	<category: 'copying'>
	^self shallowCopy postCopy
    ]

    postCopy [
	"Performs any changes required to do on a copied object. This is the
	 place where one could, for example, put code to replace objects with
	 copies of the objects"

	<category: 'copying'>
	^self
    ]

    deepCopy [
	"Returns a deep copy of the receiver (the instance variables are
	 copies of the receiver's instance variables)"

	<category: 'copying'>
	| class aCopy num |
	class := self class.
	aCopy := self shallowCopy.
	class isPointers 
	    ifTrue: [num := class instSize + self basicSize]
	    ifFalse: [num := class instSize].

	"copy the instance variables (if any)"
	1 to: num do: [:i | aCopy instVarAt: i put: (self instVarAt: i) copy].
	^aCopy
    ]

    species [
	"This method has no unique definition. Generally speaking, methods which
	 always return the same type usually don't use #class, but #species.
	 For example, a PositionableStream's species is the class of the collection
	 on which it is streaming (used by upTo:, upToAll:, upToEnd). Stream uses
	 species for obtaining the class of next:'s return value, Collection uses
	 it in its #copyEmpty: message, which in turn is used by all collection-returning
	 methods. An Interval's species is Array (used by collect:, select:,
	 reject:, etc.)."

	<category: 'class type methods'>
	^self class
    ]

    yourself [
	"Answer the receiver"

	<category: 'class type methods'>
	^self
    ]

    addDependent: anObject [
	"Add anObject to the set of the receiver's dependents. Important:
	 if an object has dependents, it won't be garbage collected."

	<category: 'dependents access'>
	^(Dependencies at: self ifAbsentPut: [OrderedCollection new]) 
	    add: anObject
    ]

    removeDependent: anObject [
	"Remove anObject to the set of the receiver's dependents. No problem
	 if anObject is not in the set of the receiver's dependents."

	<category: 'dependents access'>
	| dependencies |
	dependencies := Dependencies at: self ifAbsent: [^anObject].
	dependencies remove: anObject ifAbsent: [].
	dependencies size < 1 ifTrue: [
	    Dependencies removeKey: self ifAbsent: []].
	^anObject
    ]

    dependents [
	"Answer a collection of the receiver's dependents."

	<category: 'dependents access'>
	| dependencies |
	dependencies := Dependencies at: self ifAbsent: [^OrderedCollection new].
	^dependencies asOrderedCollection
    ]

    release [
	"Remove all of the receiver's dependents from the set and allow the
	 receiver to be garbage collected."

	<category: 'dependents access'>
	Dependencies removeKey: self ifAbsent: []
    ]

    addToBeFinalized [
	"Arrange things so that #finalize is sent to the object when the garbage
	 collector finds out there are only weak references to it."

	<category: 'finalization'>
	self class finalizableObjects add: ((HomedAssociation 
		    key: self
		    value: nil
		    environment: FinalizableObjects)
		    makeEphemeron;
		    yourself)
    ]

    removeToBeFinalized [
	"Unregister the object, so that #finalize is no longer sent to the object
	 when the garbage collector finds out there are only weak references to it."

	<category: 'finalization'>
	self class finalizableObjects remove: (HomedAssociation 
		    key: self
		    value: nil
		    environment: self class finalizableObjects)
	    ifAbsent: []
    ]

    mourn [
	"This method is sent by the VM to weak and ephemeron objects when one of
	 their fields is found out to be garbage collectable (this means, for weak
	 objects, that there are no references to it from non-weak objects, and
	 for ephemeron objects, that the only paths to the first instance variable
	 pass through other instance variables of the same ephemeron).  The default
	 behavior is to do nothing."

	<category: 'finalization'>
	
    ]

    finalize [
	"Do nothing by default"

	<category: 'finalization'>
	
    ]

    changed [
	"Send update: for each of the receiver's dependents, passing them the
	 receiver"

	<category: 'change and update'>
	self changed: self
    ]

    changed: aParameter [
	"Send update: for each of the receiver's dependents, passing them
	 aParameter"

	<category: 'change and update'>
	| dependencies |
	dependencies := Object dependencies at: self ifAbsent: [nil].
	dependencies notNil 
	    ifTrue: [dependencies do: [:dependent | dependent update: aParameter]]
    ]

    update: aParameter [
	"Default behavior is to do nothing. Called by #changed and #changed:"

	<category: 'change and update'>
	
    ]

    broadcast: aSymbol [
	"Send the unary message aSymbol to each of the receiver's dependents"

	<category: 'change and update'>
	| dependencies |
	dependencies := Object dependencies at: self ifAbsent: [nil].
	dependencies notNil 
	    ifTrue: [dependencies do: [:dependent | dependent perform: aSymbol]]
    ]

    broadcast: aSymbol with: anObject [
	"Send the message aSymbol to each of the receiver's dependents, passing
	 anObject"

	<category: 'change and update'>
	| dependencies |
	dependencies := Object dependencies at: self ifAbsent: [nil].
	dependencies notNil 
	    ifTrue: 
		[dependencies do: [:dependent | dependent perform: aSymbol with: anObject]]
    ]

    broadcast: aSymbol with: arg1 with: arg2 [
	"Send the message aSymbol to each of the receiver's dependents, passing
	 arg1 and arg2 as parameters"

	<category: 'change and update'>
	| dependencies |
	dependencies := Object dependencies at: self ifAbsent: [nil].
	dependencies notNil 
	    ifTrue: 
		[dependencies do: 
			[:dependent | 
			dependent 
			    perform: aSymbol
			    with: arg1
			    with: arg2]]
    ]

    broadcast: aSymbol withBlock: aBlock [
	"Send the message aSymbol to each of the receiver's dependents, passing
	 the result of evaluating aBlock with each dependent as the parameter"

	<category: 'change and update'>
	| dependencies |
	dependencies := Object dependencies at: self ifAbsent: [nil].
	dependencies notNil 
	    ifTrue: 
		[dependencies 
		    do: [:dependent | dependent perform: aSymbol with: (aBlock value: dependent)]]
    ]

    broadcast: aSymbol withArguments: anArray [
	"Send the message aSymbol to each of the receiver's dependents, passing
	 the parameters in anArray"

	<category: 'change and update'>
	| dependencies |
	dependencies := Object dependencies at: self ifAbsent: [nil].
	dependencies notNil 
	    ifTrue: 
		[dependencies 
		    do: [:dependent | dependent perform: aSymbol withArguments: anArray]]
    ]

    -> anObject [
	"Creates a new instance of Association with the receiver being the key
	 and the argument becoming the value"

	<category: 'syntax shortcuts'>
	^Association key: self value: anObject
    ]

    displayString [
	"Answer a String representing the receiver. For most objects
	 this is simply its #printString, but for strings and characters,
	 superfluous dollars or extra pair of quotes are stripped."

	<category: 'printing'>
	| stream |
	stream := WriteStream on: String new.
	self displayOn: stream.
	^stream contents
    ]

    displayOn: aStream [
	"Print a represention of the receiver on aStream. For most objects
	 this is simply its #printOn: representation, but for strings and
	 characters, superfluous dollars or extra pair of quotes are stripped."

	<category: 'printing'>
	self printOn: aStream
    ]

    display [
	"Print a represention of the receiver on the Transcript (stdout the GUI
	 is not active). For most objects this is simply its #print
	 representation, but for strings and characters, superfluous dollars
	 or extra pair of quotes are stripped."

	<category: 'printing'>
	Transcript show: self displayString
    ]

    displayNl [
	"Print a represention of the receiver, then put a new line on
	 the Transcript (stdout the GUI is not active). For most objects this
	 is simply its #printNl representation, but for strings and
	 characters, superfluous dollars or extra pair of quotes are stripped."

	<category: 'printing'>
	Transcript showCr: self displayString
    ]

    printString [
	"Answer a String representing the receiver"

	<category: 'printing'>
	| stream |
	stream := WriteStream on: String new.
	self printOn: stream.
	^stream contents
    ]

    printOn: aStream [
	"Print a represention of the receiver on aStream"

	<category: 'printing'>
	aStream
	    nextPutAll: self class article;
	    space;
	    nextPutAll: self class name
    ]

    basicPrintOn: aStream [
	"Print a represention of the receiver on aStream"

	<category: 'printing'>
	aStream
	    nextPutAll: self class article;
	    space;
	    nextPutAll: self class name
    ]

    print [
	"Print a represention of the receiver on the Transcript (stdout the GUI
	 is not active)"

	<category: 'printing'>
	Transcript show: self printString
    ]

    printNl [
	"Print a represention of the receiver on stdout, put a new line
	 the Transcript (stdout the GUI is not active)"

	<category: 'printing'>
	Transcript showCr: self printString
    ]

    basicPrintNl [
	"Print a basic representation of the receiver, followed by a new line."

	<category: 'printing'>
	stdout flush.
	self basicPrint.
	stdout nextPut: Character nl; flush
    ]

    storeString [
	"Answer a String of Smalltalk code compiling to the receiver"

	<category: 'storing'>
	| stream |
	stream := WriteStream on: String new.
	self storeOn: stream.
	^stream contents
    ]

    storeLiteralOn: aStream [
	"Put a Smalltalk literal compiling to the receiver on aStream"

	<category: 'storing'>
	aStream nextPutAll: '##('.
	self storeOn: aStream.
	aStream nextPut: $)
    ]

    storeOn: aStream [
	"Put Smalltalk code compiling to the receiver on aStream"

	<category: 'storing'>
	| class hasSemi |
	class := self class.
	aStream nextPut: $(.
	aStream nextPutAll: self class storeString.
	hasSemi := false.
	class isVariable 
	    ifTrue: 
		[aStream nextPutAll: ' basicNew: '.
		self basicSize printOn: aStream]
	    ifFalse: [aStream nextPutAll: ' basicNew'].
	1 to: class instSize
	    do: 
		[:i | 
		aStream nextPutAll: ' instVarAt: '.
		i printOn: aStream.
		aStream nextPutAll: ' put: '.
		(self instVarAt: i) storeOn: aStream.
		aStream nextPut: $;.
		hasSemi := true].
	class isVariable 
	    ifTrue: 
		[1 to: self validSize
		    do: 
			[:i | 
			aStream nextPutAll: ' basicAt: '.
			i printOn: aStream.
			aStream nextPutAll: ' put: '.
			(self basicAt: i) storeOn: aStream.
			aStream nextPut: $;.
			hasSemi := true]].
	hasSemi ifTrue: [aStream nextPutAll: ' yourself'].
	aStream nextPut: $)
    ]

    store [
	"Put a String of Smalltalk code compiling to the receiver on
	 the Transcript (stdout the GUI is not active)"

	<category: 'storing'>
	Transcript show: self storeString
    ]

    storeNl [
	"Put a String of Smalltalk code compiling to the receiver, followed by
	 a new line, on the Transcript (stdout the GUI is not active)"

	<category: 'storing'>
	Transcript showCr: self storeString
    ]

    binaryRepresentationObject [
	"This method must be implemented if PluggableProxies are used with
	 the receiver's class.  The default implementation raises an exception."

	<category: 'saving and loading'>
	(ObjectDumper proxyClassFor: self) == PluggableProxy 
	    ifTrue: [self subclassResponsibility]
	    ifFalse: [self shouldNotImplement]
    ]

    postLoad [
	"Called after loading an object; must restore it to the state before
	 `preStore' was called.  Do nothing by default"

	<category: 'saving and loading'>
	
    ]

    postStore [
	"Called after an object is dumped; must restore it to the state before
	 `preStore' was called.  Call #postLoad by default"

	<category: 'saving and loading'>
	self postLoad
    ]

    preStore [
	"Called before dumping an object; it must *change* it (it must not answer
	 a new object) if necessary.  Do nothing by default"

	<category: 'saving and loading'>
	
    ]

    reconstructOriginalObject [
	"Used if an instance of the receiver's class is returned as the
	 #binaryRepresentationObject of another object.  The default implementation
	 raises an exception."

	<category: 'saving and loading'>
	self subclassResponsibility
    ]

    examine [
	"Print all the instance variables of the receiver on the Transcript"

	<category: 'debugging'>
        self examineOn: Transcript
    ]

    inspect [
	"In a GUI environment, this opens a tool to examine and modify the
	 receiver.  In the default image, it just calls #examine."

	<category: 'debugging'>
        self examineOn: Transcript
    ]

    examineOn: aStream [
	"Print all the instance variables of the receiver on aStream"

	<category: 'debugging'>
	| instVars output object |
	aStream
	    nextPutAll: 'An instance of ';
	    print: self class;
	    nl.
	instVars := self class allInstVarNames.
	1 to: instVars size + self validSize
	    do: 
		[:i | 
		object := self instVarAt: i.
		output := [object printString] on: Error
			    do: 
				[:ex | 
				ex 
				    return: '%1 %2' % 
						{object class article.
						object class name asString}].
		i <= instVars size 
		    ifTrue: 
			[aStream
			    nextPutAll: '  ';
			    nextPutAll: (instVars at: i);
			    nextPutAll: ': ']
		    ifFalse: 
			[aStream
			    nextPutAll: '  [';
			    print: i - instVars size;
			    nextPutAll: ']: '].
		aStream
		    nextPutAll: output;
		    nl]
    ]

    validSize [
	"Answer how many elements in the receiver should be inspected"

	<category: 'debugging'>
	^self basicSize
    ]

    allOwners [
	"Return an Array of Objects that point to the receiver."

	<category: 'built ins'>
	<primitive: VMpr_Object_allOwners>
	
    ]

    changeClassTo: aBehavior [
	"Mutate the class of the receiver to be aBehavior.
	 Note: Tacitly assumes that the structure is the same
	 for the original and new class!!"

	<category: 'built ins'>
	<primitive: VMpr_Object_changeClassTo>
	
    ]

    checkIndexableBounds: index ifAbsent: aBlock [
	"Private - Check the reason why an access to the given indexed
	 instance variable failed.  Evaluate aBlock for an invalid index."

	<category: 'built ins'>
	self class isFixed ifTrue: [^SystemExceptions.NotIndexable signalOn: self].
	index isInteger 
	    ifFalse: [^SystemExceptions.WrongClass signalOn: index mustBe: SmallInteger].
	^aBlock value
    ]

    checkIndexableBounds: index [
	"Private - Check the reason why an access to the given indexed
	 instance variable failed"

	<category: 'built ins'>
	self class isFixed ifTrue: [^SystemExceptions.NotIndexable signalOn: self].
	index isInteger 
	    ifFalse: [^SystemExceptions.WrongClass signalOn: index mustBe: SmallInteger].
	index < 1 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index].
	index > self basicSize 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index]
    ]

    checkIndexableBounds: index put: object [
	"Private - Check the reason why a store to the given indexed
	 instance variable failed"

	<category: 'built ins'>
	| shape size |
	self class isFixed ifTrue: [^SystemExceptions.NotIndexable signalOn: self].
	self isReadOnly ifTrue: [^SystemExceptions.ReadOnlyObject signal].
	index isInteger 
	    ifFalse: [^SystemExceptions.WrongClass signalOn: index mustBe: SmallInteger].
	index < 1 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index].
	index > self basicSize 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index].
	shape := self class shape.
	(shape == #float or: [shape == #double]) 
	    ifTrue: 
		[SystemExceptions.WrongClass signalOn: object
		    mustBe: 
			{Float.
			SmallInteger}].
	(object isKindOf: Character) 
	    ifFalse: 
		[(shape == #character or: [shape == #utf32]) 
		    ifTrue: [SystemExceptions.WrongClass signalOn: object mustBe: Character]].
	shape == #character 
	    ifTrue: 
		[^SystemExceptions.ArgumentOutOfRange 
		    signalOn: object
		    mustBeBetween: (Character value: 0)
		    and: (Character value: 255)].
	shape == #utf32 
	    ifTrue: 
		[^SystemExceptions.ArgumentOutOfRange 
		    signalOn: object
		    mustBeBetween: 0 asCharacter
		    and: 1114111 asCharacter].
	shape == #byte ifTrue: [size := 8].
	shape == #int8 ifTrue: [size := 7].
	shape == #ushort ifTrue: [size := 16].
	shape == #short ifTrue: [size := 15].
	shape == #uint ifTrue: [size := 32].
	shape == #int ifTrue: [size := 31].
	shape == #uint64 ifTrue: [size := 64].
	shape == #int64 ifTrue: [size := 63].
	size isNil ifTrue: [^self primtiveFailed].
	^SystemExceptions.ArgumentOutOfRange 
	    signalOn: object
	    mustBeBetween: (size odd ifTrue: [-1 bitShift: size] ifFalse: [0])
	    and: (1 bitShift: size) - 1
    ]

    at: anIndex [
	"Answer the index-th indexed instance variable of the receiver"

	<category: 'built ins'>
	<primitive: VMpr_Object_basicAt>
	self checkIndexableBounds: anIndex
    ]

    basicAt: anIndex [
	"Answer the index-th indexed instance variable of the receiver.
	 This method must not be overridden, override at: instead"

	<category: 'built ins'>
	<primitive: VMpr_Object_basicAt>
	self checkIndexableBounds: anIndex
    ]

    at: anIndex put: value [
	"Store value in the index-th indexed instance variable of the receiver"

	<category: 'built ins'>
	<primitive: VMpr_Object_basicAtPut>
	self checkIndexableBounds: anIndex put: value
    ]

    basicAt: anIndex put: value [
	"Store value in the index-th indexed instance variable of the receiver
	 This method must not be overridden, override at:put: instead"

	<category: 'built ins'>
	<primitive: VMpr_Object_basicAtPut>
	self checkIndexableBounds: anIndex put: value
    ]

    size [
	"Answer the number of indexed instance variable in the receiver"

	<category: 'built ins'>
	<primitive: VMpr_Object_basicSize>
	
    ]

    basicSize [
	"Answer the number of indexed instance variable in the receiver"

	<category: 'built ins'>
	<primitive: VMpr_Object_basicSize>
	
    ]

    becomeForward: otherObject [
	"Change all references to the receiver into references to otherObject.
	 References to otherObject are not transformed into the receiver.
	 Answer the receiver so that it is not lost."

	<category: 'built ins'>
	<primitive: VMpr_Object_becomeForward>
	^SystemExceptions.ReadOnlyObject signal
    ]

    become: otherObject [
	"Change all references to the receiver into references to otherObject.
	 Depending on the implementation, references to otherObject might or
	 might not be transformed into the receiver (respectively,
	 'two-way become' and 'one-way become').
	 Implementations doing one-way become answer the receiver (so that it is
	 not lost). Most implementations doing two-way become answer otherObject,
	 but this is not assured - so do answer the receiver for consistency.
	 GNU Smalltalk does two-way become and answers otherObject, but this
	 might change in future versions: programs should not rely on the behavior
	 and results of #become: ."

	<category: 'built ins'>
	<primitive: VMpr_Object_become>
	^SystemExceptions.ReadOnlyObject signal
    ]

    shallowCopy [
	"Returns a shallow copy of the receiver (the instance variables are
	 not copied)"

	<category: 'built ins'>
	"This is a primitive for speed.  An alternative implementation is
	 found below."

	| class aCopy |
	<primitive: VMpr_Object_shallowCopy>
	class := self class.
	class isVariable 
	    ifTrue: [aCopy := class basicNew: self basicSize]
	    ifFalse: [aCopy := class basicNew].

	"copy the instance variables (if any)"
	1 to: class instSize + self basicSize
	    do: [:i | aCopy instVarAt: i put: (self instVarAt: i)].
	^aCopy
    ]

    makeFixed [
	"Avoid that the receiver moves in memory across garbage collections."

	"We are an integer - fail"

	<category: 'built ins'>
	<primitive: VMpr_Object_makeFixed>
	SystemExceptions.InvalidValue signalOn: self
	    reason: 'Instances of Integer cannot be tenured!'
    ]

    tenure [
	"Move the object to oldspace."

	"We are an integer - they won't notice the difference so don't
	 fail."

	<category: 'built ins'>
	<primitive: VMpr_Object_tenure>
	
    ]

    instVarNamed: aString [
	"Answer the instance variable named aString in the receiver."

	<category: 'introspection'>
	^self instVarAt: (self class indexOfInstVar: aString)
    ]

    instVarNamed: aString put: anObject [
	"Answer the instance variable named aString in the receiver."

	<category: 'introspection'>
	^self instVarAt: (self class indexOfInstVar: aString) put: anObject
    ]

    instVarAt: index [
	"Answer the index-th instance variable of the receiver.
	 This method must not be overridden."

	<category: 'built ins'>
	<primitive: VMpr_Object_instVarAt>
	index < 1 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index].
	index isInteger 
	    ifFalse: [^SystemExceptions.WrongClass signalOn: index mustBe: SmallInteger].
	index > (self basicSize + self class instSize) 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index].
	^self basicAt: index - self class instSize
    ]

    instVarAt: index put: value [
	"Store value in the index-th instance variable of the receiver.
	 This method must not be overridden."

	<category: 'built ins'>
	<primitive: VMpr_Object_instVarAtPut>
	self isReadOnly ifTrue: [^SystemExceptions.ReadOnlyObject signal].
	index < 1 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index].
	index isInteger 
	    ifFalse: [^SystemExceptions.WrongClass signalOn: index mustBe: SmallInteger].
	index > (self basicSize + self class instSize) 
	    ifTrue: [^SystemExceptions.IndexOutOfRange signalOn: self withIndex: index].
	^self basicAt: index - self class instSize put: value
    ]

    isReadOnly [
	"Answer whether the object's indexed instance variables can be
	 written"

	<category: 'built ins'>
	<primitive: VMpr_Object_isReadOnly>
	
    ]

    isUntrusted [
	"Answer whether the object is to be considered untrusted."

	<category: 'built ins'>
	<primitive: VMpr_Object_isUntrusted>
	
    ]

    makeReadOnly: aBoolean [
	"Set whether the object's indexed instance variables can be written"

	<category: 'built ins'>
	<primitive: VMpr_Object_makeReadOnly>
	SystemExceptions.WrongClass signalOn: aBoolean mustBe: Boolean
    ]

    makeUntrusted: aBoolean [
	"Set whether the object is to be considered untrusted."

	<category: 'built ins'>
	<primitive: VMpr_Object_makeUntrusted>
	SystemExceptions.WrongClass signalOn: aBoolean mustBe: Boolean
    ]

    makeWeak [
	"Make the object a 'weak' one. When an object is only referenced by weak
	 objects, it is collected and the slots in the weak objects are changed to
	 nils by the VM; the weak object is then sent the #mourn message."

	<category: 'built ins'>
	<primitive: VMpr_Object_makeWeak>
	
    ]

    makeEphemeron [
	"Make the object an 'ephemeron'.  An ephemeron is marked after all
	 other objects, and if no references are found to the key except from
	 the object itself, it is sent the #mourn message."

	<category: 'built ins'>
	<primitive: VMpr_Object_makeEphemeron>
	SystemExceptions.InvalidValue signalOn: self
	    reason: 'ephemerons should have at least one instance variables'
    ]

    asOop [
	"Answer the object index associated to the receiver. The object
	 index doesn't change when garbage collection is performed."

	"We are an integer - fail"

	<category: 'built ins'>
	<primitive: VMpr_Object_hash>
	SystemExceptions.InvalidValue signalOn: self
	    reason: 'Instances of Integer have no associated OOP!'
    ]

    identityHash [
	"Answer an hash value for the receiver. This method must not be
	 overridden"

	"We are an integer - answer the receiver"

	<category: 'built ins'>
	<primitive: VMpr_Object_hash>
	^self
    ]

    hash [
	"Answer an hash value for the receiver. This hash value is ok
	 for objects that do not redefine ==."

	"We are an integer - answer the receiver"

	<category: 'built ins'>
	<primitive: VMpr_Object_hash>
	^self
    ]

    nextInstance [
	"Private - answer another instance of the receiver's class, or
	 nil if the entire object table has been walked"

	<category: 'built ins'>
	<primitive: VMpr_Object_nextInstance>
	^nil
    ]

    perform: selectorOrMessageOrMethod [
	"Send the unary message named selectorOrMessageOrMethod (if a Symbol)
	 to the receiver, or the message and arguments it identifies (if a Message
	 or DirectedMessage), or finally execute the method within the receiver
	 (if a CompiledMethod).  In the last case, the method need not reside on
	 the hierarchy from the receiver's class to Object -- it need not reside
	 at all in a MethodDictionary, in fact -- but doing bad things will
	 compromise stability of the Smalltalk virtual machine (and don't blame
	 anybody but yourself).
	 
	 This method should not be overridden"

	<category: 'built ins'>
	<primitive: VMpr_Object_perform>
	selectorOrMessageOrMethod isSymbol 
	    ifTrue: 
		[(self respondsTo: selectorOrMessageOrMethod) 
		    ifTrue: [^SystemExceptions.WrongArgumentCount signal]
		    ifFalse: 
			[self doesNotUnderstand: (Message selector: selectorOrMessageOrMethod
				    arguments: #())]].
	(selectorOrMessageOrMethod isKindOf: CompiledMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal].
	^selectorOrMessageOrMethod sendTo: self
    ]

    perform: selectorOrMethod with: arg1 [
	"Send the message named selectorOrMethod (if a Symbol) to the receiver,
	 passing arg1 to it, or execute the method within the receiver
	 (if a CompiledMethod).  In the latter case, the method need not reside on
	 the hierarchy from the receiver's class to Object -- it need not reside
	 at all in a MethodDictionary, in fact -- but doing bad things will
	 compromise stability of the Smalltalk virtual machine (and don't blame
	 anybody but yourself).
	 
	 This method should not be overridden"

	<category: 'built ins'>
	<primitive: VMpr_Object_perform>
	(selectorOrMethod isKindOf: CompiledMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal].
	selectorOrMethod isSymbol 
	    ifFalse: 
		[SystemExceptions.WrongClass signalOn: selectorOrMethod mustBe: Symbol].
	(self respondsTo: selectorOrMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal]
	    ifFalse: 
		[self 
		    doesNotUnderstand: (Message selector: selectorOrMethod arguments: {arg1})]
    ]

    perform: selectorOrMethod with: arg1 with: arg2 [
	"Send the message named selectorOrMethod (if a Symbol) to the receiver,
	 passing arg1 and arg2 to it, or execute the method within the receiver
	 (if a CompiledMethod).  In the latter case, the method need not reside on
	 the hierarchy from the receiver's class to Object -- it need not reside
	 at all in a MethodDictionary, in fact -- but doing bad things will
	 compromise stability of the Smalltalk virtual machine (and don't blame
	 anybody but yourself).
	 
	 This method should not be overridden"

	<category: 'built ins'>
	<primitive: VMpr_Object_perform>
	(selectorOrMethod isKindOf: CompiledMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal].
	selectorOrMethod isSymbol 
	    ifFalse: 
		[SystemExceptions.WrongClass signalOn: selectorOrMethod mustBe: Symbol].
	(self respondsTo: selectorOrMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal]
	    ifFalse: 
		[self doesNotUnderstand: (Message selector: selectorOrMethod
			    arguments: 
				{arg1.
				arg2})]
    ]

    perform: selectorOrMethod with: arg1 with: arg2 with: arg3 [
	"Send the message named selectorOrMethod (if a Symbol) to the receiver,
	 passing the other arguments to it, or execute the method within the
	 receiver (if a CompiledMethod).  In the latter case, the method need not
	 reside on the hierarchy from the receiver's class to Object -- it need
	 not reside at all in a MethodDictionary, in fact -- but doing bad things
	 will compromise stability of the Smalltalk virtual machine (and don't
	 blame anybody but yourself).
	 
	 This method should not be overridden"

	<category: 'built ins'>
	<primitive: VMpr_Object_perform>
	(selectorOrMethod isKindOf: CompiledMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal].
	selectorOrMethod isSymbol 
	    ifFalse: 
		[SystemExceptions.WrongClass signalOn: selectorOrMethod mustBe: Symbol].
	(self respondsTo: selectorOrMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal]
	    ifFalse: 
		[self doesNotUnderstand: (Message selector: selectorOrMethod
			    arguments: 
				{arg1.
				arg2.
				arg3})]
    ]

    perform: selectorOrMethod with: arg1 with: arg2 with: arg3 with: arg4 [
	"Send the message named selectorOrMethod (if a Symbol) to the receiver,
	 passing the other arguments to it, or execute the method within the
	 receiver (if a CompiledMethod).  In the latter case, the method need not
	 reside on the hierarchy from the receiver's class to Object -- it need
	 not reside at all in a MethodDictionary, in fact -- but doing bad things
	 will compromise stability of the Smalltalk virtual machine (and don't
	 blame anybody but yourself).
	 
	 This method should not be overridden"

	<category: 'built ins'>
	<primitive: VMpr_Object_perform>
	(selectorOrMethod isKindOf: CompiledMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal].
	selectorOrMethod isSymbol 
	    ifFalse: 
		[SystemExceptions.WrongClass signalOn: selectorOrMethod mustBe: Symbol].
	(self respondsTo: selectorOrMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal]
	    ifFalse: 
		[self doesNotUnderstand: (Message selector: selectorOrMethod
			    arguments: 
				{arg1.
				arg2.
				arg3.
				arg4})]
    ]

    perform: selectorOrMethod withArguments: argumentsArray [
	"Send the message named selectorOrMethod (if a Symbol) to the receiver,
	 passing the elements of argumentsArray as parameters, or execute the
	 method within the receiver (if a CompiledMethod).  In the latter case,
	 the method need not reside on the hierarchy from the receiver's class
	 to Object -- it need not reside at all in a MethodDictionary, in
	 fact -- but doing bad things will compromise stability of the Smalltalk
	 virtual machine (and don't blame anybody but yourself).
	 
	 This method should not be overridden"

	<category: 'built ins'>
	<primitive: VMpr_Object_performWithArguments>
	argumentsArray isArray 
	    ifFalse: [SystemExceptions.WrongClass signalOn: argumentsArray mustBe: Array].
	(selectorOrMethod isKindOf: CompiledMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal].
	selectorOrMethod isSymbol 
	    ifFalse: 
		[SystemExceptions.WrongClass signalOn: selectorOrMethod mustBe: Symbol].
	(self respondsTo: selectorOrMethod) 
	    ifTrue: [SystemExceptions.WrongArgumentCount signal]
	    ifFalse: 
		[self doesNotUnderstand: (Message selector: selectorOrMethod
			    arguments: argumentsArray)]
    ]

    == arg [
	"Answer whether the receiver is the same object as arg. This is a
	 very fast test and is called 'object identity'."

	<category: 'built ins'>
	<primitive: VMpr_Object_identity>
	
    ]

    = arg [
	"Answer whether the receiver is equal to arg. The equality test is
	 by default the same as that for identical objects. = must not fail;
	 answer false if the receiver cannot be compared to arg"

	<category: 'built ins'>
	<primitive: VMpr_Object_identity>
	
    ]

    class [
	"Answer the class to which the receiver belongs"

	<category: 'built ins'>
	<primitive: VMpr_Object_class>
	self primitiveFailed
    ]

    error: message [
	"Stop the execution and/or bring up a debugger. message is an error
	 message to be shown"

	<category: 'built ins'>
	<primitive: VMpr_Object_bootstrapError>
	
    ]

    basicPrint [
	"Print a basic representation of the receiver"

	<category: 'built ins'>
	<primitive: VMpr_Object_basicPrint>
	
    ]

    halt [
	"Called to enter the debugger"

	<category: 'built ins'>
	^self halt: 'halt encountered'
    ]

    halt: aString [
	"Called to enter the debugger"

	<category: 'built ins'>
	^self error: aString
    ]

    mark: aSymbol [
	"Private - use this method to mark code which needs to be reworked,
	 removed, etc. You can then find all senders of #mark: to find all marked
	 methods or you can look for all senders of the symbol that you sent to
	 #mark: to find a category of marked methods."

	<category: 'built ins'>
	
    ]

    primitiveFailed [
	"Called when a VM primitive fails"

	<category: 'built ins'>
	SystemExceptions.PrimitiveFailed signal
    ]

    shouldNotImplement [
	"Called when objects belonging to a class should not answer a
	 selector defined by a superclass"

	<category: 'built ins'>
	SystemExceptions.ShouldNotImplement signal
    ]

    subclassResponsibility [
	"Called when a method defined by a class should be overridden
	 in a subclass"

	<category: 'built ins'>
	SystemExceptions.SubclassResponsibility signal
    ]

    notYetImplemented [
	"Called when a method defined by a class is not yet implemented,
	 but is going to be"

	<category: 'built ins'>
	SystemExceptions.NotYetImplemented signal
    ]

    doesNotUnderstand: message [
	"Called by the system when a selector was not found. message is a
	 Message containing information on the receiver"

	<category: 'VM callbacks'>
	<primitive: VMpr_Object_bootstrapDNU>
	
    ]

    badReturnError [
	"Called back when a block performs a bad return."

	<category: 'VM callbacks'>
	SystemExceptions.BadReturn signal
    ]

    mustBeBoolean [
	"Called by the system when ifTrue:*, ifFalse:*, and: or or: are sent to
	 anything but a boolean"

	<category: 'VM callbacks'>
	| result |
	result := SystemExceptions.MustBeBoolean signalOn: self.
	result == false ifFalse: [result := true].
	^result
    ]

    noRunnableProcess [
	"Called back when all processes are suspended"

	<category: 'VM callbacks'>
	SystemExceptions.NoRunnableProcess signal
    ]

    userInterrupt [
	"Called back when the user presses Ctrl-Break"

	<category: 'VM callbacks'>
	SystemExceptions.UserInterrupt signal
    ]
]