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
|
# PEG grammar for Python
@trailer '''
void *
_PyPegen_parse(Parser *p)
{
// Initialize keywords
p->keywords = reserved_keywords;
p->n_keyword_lists = n_keyword_lists;
p->soft_keywords = soft_keywords;
// Run parser
void *result = NULL;
if (p->start_rule == Py_file_input) {
result = file_rule(p);
} else if (p->start_rule == Py_single_input) {
result = interactive_rule(p);
} else if (p->start_rule == Py_eval_input) {
result = eval_rule(p);
} else if (p->start_rule == Py_func_type_input) {
result = func_type_rule(p);
} else if (p->start_rule == Py_fstring_input) {
result = fstring_rule(p);
}
return result;
}
'''
# ========================= START OF THE GRAMMAR =========================
# General grammatical elements and rules:
#
# * Strings with double quotes (") denote SOFT KEYWORDS
# * Strings with single quotes (') denote KEYWORDS
# * Upper case names (NAME) denote tokens in the Grammar/Tokens file
# * Rule names starting with "invalid_" are used for specialized syntax errors
# - These rules are NOT used in the first pass of the parser.
# - Only if the first pass fails to parse, a second pass including the invalid
# rules will be executed.
# - If the parser fails in the second phase with a generic syntax error, the
# location of the generic failure of the first pass will be used (this avoids
# reporting incorrect locations due to the invalid rules).
# - The order of the alternatives involving invalid rules matter
# (like any rule in PEG).
#
# Grammar Syntax (see PEP 617 for more information):
#
# rule_name: expression
# Optionally, a type can be included right after the rule name, which
# specifies the return type of the C or Python function corresponding to the
# rule:
# rule_name[return_type]: expression
# If the return type is omitted, then a void * is returned in C and an Any in
# Python.
# e1 e2
# Match e1, then match e2.
# e1 | e2
# Match e1 or e2.
# The first alternative can also appear on the line after the rule name for
# formatting purposes. In that case, a | must be used before the first
# alternative, like so:
# rule_name[return_type]:
# | first_alt
# | second_alt
# ( e )
# Match e (allows also to use other operators in the group like '(e)*')
# [ e ] or e?
# Optionally match e.
# e*
# Match zero or more occurrences of e.
# e+
# Match one or more occurrences of e.
# s.e+
# Match one or more occurrences of e, separated by s. The generated parse tree
# does not include the separator. This is otherwise identical to (e (s e)*).
# &e
# Succeed if e can be parsed, without consuming any input.
# !e
# Fail if e can be parsed, without consuming any input.
# ~
# Commit to the current alternative, even if it fails to parse.
#
# STARTING RULES
# ==============
file[mod_ty]: a=[statements] ENDMARKER { _PyPegen_make_module(p, a) }
interactive[mod_ty]: a=statement_newline { _PyAST_Interactive(a, p->arena) }
eval[mod_ty]: a=expressions NEWLINE* ENDMARKER { _PyAST_Expression(a, p->arena) }
func_type[mod_ty]: '(' a=[type_expressions] ')' '->' b=expression NEWLINE* ENDMARKER { _PyAST_FunctionType(a, b, p->arena) }
fstring[expr_ty]: star_expressions
# GENERAL STATEMENTS
# ==================
statements[asdl_stmt_seq*]: a=statement+ { (asdl_stmt_seq*)_PyPegen_seq_flatten(p, a) }
statement[asdl_stmt_seq*]: a=compound_stmt { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a) } | a[asdl_stmt_seq*]=simple_stmts { a }
statement_newline[asdl_stmt_seq*]:
| a=compound_stmt NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a) }
| simple_stmts
| NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, CHECK(stmt_ty, _PyAST_Pass(EXTRA))) }
| ENDMARKER { _PyPegen_interactive_exit(p) }
simple_stmts[asdl_stmt_seq*]:
| a=simple_stmt !';' NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a) } # Not needed, there for speedup
| a[asdl_stmt_seq*]=';'.simple_stmt+ [';'] NEWLINE { a }
# NOTE: assignment MUST precede expression, else parsing a simple assignment
# will throw a SyntaxError.
simple_stmt[stmt_ty] (memo):
| assignment
| &"type" type_alias
| e=star_expressions { _PyAST_Expr(e, EXTRA) }
| &'return' return_stmt
| &('import' | 'from') import_stmt
| &'raise' raise_stmt
| 'pass' { _PyAST_Pass(EXTRA) }
| &'del' del_stmt
| &'yield' yield_stmt
| &'assert' assert_stmt
| 'break' { _PyAST_Break(EXTRA) }
| 'continue' { _PyAST_Continue(EXTRA) }
| &'global' global_stmt
| &'nonlocal' nonlocal_stmt
compound_stmt[stmt_ty]:
| &('def' | '@' | ASYNC) function_def
| &'if' if_stmt
| &('class' | '@') class_def
| &('with' | ASYNC) with_stmt
| &('for' | ASYNC) for_stmt
| &'try' try_stmt
| &'while' while_stmt
| match_stmt
# SIMPLE STATEMENTS
# =================
# NOTE: annotated_rhs may start with 'yield'; yield_expr must start with 'yield'
assignment[stmt_ty]:
| a=NAME ':' b=expression c=['=' d=annotated_rhs { d }] {
CHECK_VERSION(
stmt_ty,
6,
"Variable annotation syntax is",
_PyAST_AnnAssign(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), b, c, 1, EXTRA)
) }
| a=('(' b=single_target ')' { b }
| single_subscript_attribute_target) ':' b=expression c=['=' d=annotated_rhs { d }] {
CHECK_VERSION(stmt_ty, 6, "Variable annotations syntax is", _PyAST_AnnAssign(a, b, c, 0, EXTRA)) }
| a[asdl_expr_seq*]=(z=star_targets '=' { z })+ b=(yield_expr | star_expressions) !'=' tc=[TYPE_COMMENT] {
_PyAST_Assign(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
| a=single_target b=augassign ~ c=(yield_expr | star_expressions) {
_PyAST_AugAssign(a, b->kind, c, EXTRA) }
| invalid_assignment
annotated_rhs[expr_ty]: yield_expr | star_expressions
augassign[AugOperator*]:
| '+=' { _PyPegen_augoperator(p, Add) }
| '-=' { _PyPegen_augoperator(p, Sub) }
| '*=' { _PyPegen_augoperator(p, Mult) }
| '@=' { CHECK_VERSION(AugOperator*, 5, "The '@' operator is", _PyPegen_augoperator(p, MatMult)) }
| '/=' { _PyPegen_augoperator(p, Div) }
| '%=' { _PyPegen_augoperator(p, Mod) }
| '&=' { _PyPegen_augoperator(p, BitAnd) }
| '|=' { _PyPegen_augoperator(p, BitOr) }
| '^=' { _PyPegen_augoperator(p, BitXor) }
| '<<=' { _PyPegen_augoperator(p, LShift) }
| '>>=' { _PyPegen_augoperator(p, RShift) }
| '**=' { _PyPegen_augoperator(p, Pow) }
| '//=' { _PyPegen_augoperator(p, FloorDiv) }
return_stmt[stmt_ty]:
| 'return' a=[star_expressions] { _PyAST_Return(a, EXTRA) }
raise_stmt[stmt_ty]:
| 'raise' a=expression b=['from' z=expression { z }] { _PyAST_Raise(a, b, EXTRA) }
| 'raise' { _PyAST_Raise(NULL, NULL, EXTRA) }
global_stmt[stmt_ty]: 'global' a[asdl_expr_seq*]=','.NAME+ {
_PyAST_Global(CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p, a)), EXTRA) }
nonlocal_stmt[stmt_ty]: 'nonlocal' a[asdl_expr_seq*]=','.NAME+ {
_PyAST_Nonlocal(CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p, a)), EXTRA) }
del_stmt[stmt_ty]:
| 'del' a=del_targets &(';' | NEWLINE) { _PyAST_Delete(a, EXTRA) }
| invalid_del_stmt
yield_stmt[stmt_ty]: y=yield_expr { _PyAST_Expr(y, EXTRA) }
assert_stmt[stmt_ty]: 'assert' a=expression b=[',' z=expression { z }] { _PyAST_Assert(a, b, EXTRA) }
import_stmt[stmt_ty]:
| invalid_import
| import_name
| import_from
# Import statements
# -----------------
import_name[stmt_ty]: 'import' a=dotted_as_names { _PyAST_Import(a, EXTRA) }
# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
import_from[stmt_ty]:
| 'from' a=('.' | '...')* b=dotted_name 'import' c=import_from_targets {
_PyAST_ImportFrom(b->v.Name.id, c, _PyPegen_seq_count_dots(a), EXTRA) }
| 'from' a=('.' | '...')+ 'import' b=import_from_targets {
_PyAST_ImportFrom(NULL, b, _PyPegen_seq_count_dots(a), EXTRA) }
import_from_targets[asdl_alias_seq*]:
| '(' a=import_from_as_names [','] ')' { a }
| import_from_as_names !','
| '*' { (asdl_alias_seq*)_PyPegen_singleton_seq(p, CHECK(alias_ty, _PyPegen_alias_for_star(p, EXTRA))) }
| invalid_import_from_targets
import_from_as_names[asdl_alias_seq*]:
| a[asdl_alias_seq*]=','.import_from_as_name+ { a }
import_from_as_name[alias_ty]:
| a=NAME b=['as' z=NAME { z }] { _PyAST_alias(a->v.Name.id,
(b) ? ((expr_ty) b)->v.Name.id : NULL,
EXTRA) }
dotted_as_names[asdl_alias_seq*]:
| a[asdl_alias_seq*]=','.dotted_as_name+ { a }
dotted_as_name[alias_ty]:
| a=dotted_name b=['as' z=NAME { z }] { _PyAST_alias(a->v.Name.id,
(b) ? ((expr_ty) b)->v.Name.id : NULL,
EXTRA) }
dotted_name[expr_ty]:
| a=dotted_name '.' b=NAME { _PyPegen_join_names_with_dot(p, a, b) }
| NAME
# COMPOUND STATEMENTS
# ===================
# Common elements
# ---------------
block[asdl_stmt_seq*] (memo):
| NEWLINE INDENT a=statements DEDENT { a }
| simple_stmts
| invalid_block
decorators[asdl_expr_seq*]: a[asdl_expr_seq*]=('@' f=named_expression NEWLINE { f })+ { a }
# Class definitions
# -----------------
class_def[stmt_ty]:
| a=decorators b=class_def_raw { _PyPegen_class_def_decorators(p, a, b) }
| class_def_raw
class_def_raw[stmt_ty]:
| invalid_class_def_raw
| 'class' a=NAME t=[type_params] b=['(' z=[arguments] ')' { z }] ':' c=block {
_PyAST_ClassDef(a->v.Name.id, t,
(b) ? ((expr_ty) b)->v.Call.args : NULL,
(b) ? ((expr_ty) b)->v.Call.keywords : NULL,
c, NULL, EXTRA) }
# Function definitions
# --------------------
function_def[stmt_ty]:
| d=decorators f=function_def_raw { _PyPegen_function_def_decorators(p, d, f) }
| function_def_raw
function_def_raw[stmt_ty]:
| invalid_def_raw
| 'def' n=NAME t=[type_params] &&'(' params=[params] ')' a=['->' z=expression { z }] &&':' tc=[func_type_comment] b=block {
_PyAST_FunctionDef(n->v.Name.id, t,
(params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
b, NULL, a, NEW_TYPE_COMMENT(p, tc), EXTRA) }
| ASYNC 'def' n=NAME t=[type_params] &&'(' params=[params] ')' a=['->' z=expression { z }] &&':' tc=[func_type_comment] b=block {
CHECK_VERSION(
stmt_ty,
5,
"Async functions are",
_PyAST_AsyncFunctionDef(n->v.Name.id, t,
(params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
b, NULL, a, NEW_TYPE_COMMENT(p, tc), EXTRA)
) }
# Function parameters
# -------------------
params[arguments_ty]:
| invalid_parameters
| parameters
parameters[arguments_ty]:
| a=slash_no_default b[asdl_arg_seq*]=param_no_default* c=param_with_default* d=[star_etc] {
CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, a, NULL, b, c, d)) }
| a=slash_with_default b=param_with_default* c=[star_etc] {
CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, NULL, a, NULL, b, c)) }
| a[asdl_arg_seq*]=param_no_default+ b=param_with_default* c=[star_etc] {
_PyPegen_make_arguments(p, NULL, NULL, a, b, c) }
| a=param_with_default+ b=[star_etc] { _PyPegen_make_arguments(p, NULL, NULL, NULL, a, b)}
| a=star_etc { _PyPegen_make_arguments(p, NULL, NULL, NULL, NULL, a) }
# Some duplication here because we can't write (',' | &')'),
# which is because we don't support empty alternatives (yet).
slash_no_default[asdl_arg_seq*]:
| a[asdl_arg_seq*]=param_no_default+ '/' ',' { a }
| a[asdl_arg_seq*]=param_no_default+ '/' &')' { a }
slash_with_default[SlashWithDefault*]:
| a=param_no_default* b=param_with_default+ '/' ',' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
| a=param_no_default* b=param_with_default+ '/' &')' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
star_etc[StarEtc*]:
| invalid_star_etc
| '*' a=param_no_default b=param_maybe_default* c=[kwds] {
_PyPegen_star_etc(p, a, b, c) }
| '*' a=param_no_default_star_annotation b=param_maybe_default* c=[kwds] {
_PyPegen_star_etc(p, a, b, c) }
| '*' ',' b=param_maybe_default+ c=[kwds] {
_PyPegen_star_etc(p, NULL, b, c) }
| a=kwds { _PyPegen_star_etc(p, NULL, NULL, a) }
kwds[arg_ty]:
| invalid_kwds
| '**' a=param_no_default { a }
# One parameter. This *includes* a following comma and type comment.
#
# There are three styles:
# - No default
# - With default
# - Maybe with default
#
# There are two alternative forms of each, to deal with type comments:
# - Ends in a comma followed by an optional type comment
# - No comma, optional type comment, must be followed by close paren
# The latter form is for a final parameter without trailing comma.
#
param_no_default[arg_ty]:
| a=param ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
| a=param tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
param_no_default_star_annotation[arg_ty]:
| a=param_star_annotation ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
| a=param_star_annotation tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
param_with_default[NameDefaultPair*]:
| a=param c=default ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
| a=param c=default tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
param_maybe_default[NameDefaultPair*]:
| a=param c=default? ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
| a=param c=default? tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
param[arg_ty]: a=NAME b=annotation? { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
param_star_annotation[arg_ty]: a=NAME b=star_annotation { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
annotation[expr_ty]: ':' a=expression { a }
star_annotation[expr_ty]: ':' a=star_expression { a }
default[expr_ty]: '=' a=expression { a } | invalid_default
# If statement
# ------------
if_stmt[stmt_ty]:
| invalid_if_stmt
| 'if' a=named_expression ':' b=block c=elif_stmt {
_PyAST_If(a, b, CHECK(asdl_stmt_seq*, _PyPegen_singleton_seq(p, c)), EXTRA) }
| 'if' a=named_expression ':' b=block c=[else_block] { _PyAST_If(a, b, c, EXTRA) }
elif_stmt[stmt_ty]:
| invalid_elif_stmt
| 'elif' a=named_expression ':' b=block c=elif_stmt {
_PyAST_If(a, b, CHECK(asdl_stmt_seq*, _PyPegen_singleton_seq(p, c)), EXTRA) }
| 'elif' a=named_expression ':' b=block c=[else_block] { _PyAST_If(a, b, c, EXTRA) }
else_block[asdl_stmt_seq*]:
| invalid_else_stmt
| 'else' &&':' b=block { b }
# While statement
# ---------------
while_stmt[stmt_ty]:
| invalid_while_stmt
| 'while' a=named_expression ':' b=block c=[else_block] { _PyAST_While(a, b, c, EXTRA) }
# For statement
# -------------
for_stmt[stmt_ty]:
| invalid_for_stmt
| 'for' t=star_targets 'in' ~ ex=star_expressions ':' tc=[TYPE_COMMENT] b=block el=[else_block] {
_PyAST_For(t, ex, b, el, NEW_TYPE_COMMENT(p, tc), EXTRA) }
| ASYNC 'for' t=star_targets 'in' ~ ex=star_expressions ':' tc=[TYPE_COMMENT] b=block el=[else_block] {
CHECK_VERSION(stmt_ty, 5, "Async for loops are", _PyAST_AsyncFor(t, ex, b, el, NEW_TYPE_COMMENT(p, tc), EXTRA)) }
| invalid_for_target
# With statement
# --------------
with_stmt[stmt_ty]:
| invalid_with_stmt_indent
| 'with' '(' a[asdl_withitem_seq*]=','.with_item+ ','? ')' ':' b=block {
CHECK_VERSION(stmt_ty, 9, "Parenthesized context managers are", _PyAST_With(a, b, NULL, EXTRA)) }
| 'with' a[asdl_withitem_seq*]=','.with_item+ ':' tc=[TYPE_COMMENT] b=block {
_PyAST_With(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
| ASYNC 'with' '(' a[asdl_withitem_seq*]=','.with_item+ ','? ')' ':' b=block {
CHECK_VERSION(stmt_ty, 5, "Async with statements are", _PyAST_AsyncWith(a, b, NULL, EXTRA)) }
| ASYNC 'with' a[asdl_withitem_seq*]=','.with_item+ ':' tc=[TYPE_COMMENT] b=block {
CHECK_VERSION(stmt_ty, 5, "Async with statements are", _PyAST_AsyncWith(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA)) }
| invalid_with_stmt
with_item[withitem_ty]:
| e=expression 'as' t=star_target &(',' | ')' | ':') { _PyAST_withitem(e, t, p->arena) }
| invalid_with_item
| e=expression { _PyAST_withitem(e, NULL, p->arena) }
# Try statement
# -------------
try_stmt[stmt_ty]:
| invalid_try_stmt
| 'try' &&':' b=block f=finally_block { _PyAST_Try(b, NULL, NULL, f, EXTRA) }
| 'try' &&':' b=block ex[asdl_excepthandler_seq*]=except_block+ el=[else_block] f=[finally_block] { _PyAST_Try(b, ex, el, f, EXTRA) }
| 'try' &&':' b=block ex[asdl_excepthandler_seq*]=except_star_block+ el=[else_block] f=[finally_block] {
CHECK_VERSION(stmt_ty, 11, "Exception groups are",
_PyAST_TryStar(b, ex, el, f, EXTRA)) }
# Except statement
# ----------------
except_block[excepthandler_ty]:
| invalid_except_stmt_indent
| 'except' e=expression t=['as' z=NAME { z }] ':' b=block {
_PyAST_ExceptHandler(e, (t) ? ((expr_ty) t)->v.Name.id : NULL, b, EXTRA) }
| 'except' ':' b=block { _PyAST_ExceptHandler(NULL, NULL, b, EXTRA) }
| invalid_except_stmt
except_star_block[excepthandler_ty]:
| invalid_except_star_stmt_indent
| 'except' '*' e=expression t=['as' z=NAME { z }] ':' b=block {
_PyAST_ExceptHandler(e, (t) ? ((expr_ty) t)->v.Name.id : NULL, b, EXTRA) }
| invalid_except_stmt
finally_block[asdl_stmt_seq*]:
| invalid_finally_stmt
| 'finally' &&':' a=block { a }
# Match statement
# ---------------
match_stmt[stmt_ty]:
| "match" subject=subject_expr ':' NEWLINE INDENT cases[asdl_match_case_seq*]=case_block+ DEDENT {
CHECK_VERSION(stmt_ty, 10, "Pattern matching is", _PyAST_Match(subject, cases, EXTRA)) }
| invalid_match_stmt
subject_expr[expr_ty]:
| value=star_named_expression ',' values=star_named_expressions? {
_PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, value, values)), Load, EXTRA) }
| named_expression
case_block[match_case_ty]:
| invalid_case_block
| "case" pattern=patterns guard=guard? ':' body=block {
_PyAST_match_case(pattern, guard, body, p->arena) }
guard[expr_ty]: 'if' guard=named_expression { guard }
patterns[pattern_ty]:
| patterns[asdl_pattern_seq*]=open_sequence_pattern {
_PyAST_MatchSequence(patterns, EXTRA) }
| pattern
pattern[pattern_ty]:
| as_pattern
| or_pattern
as_pattern[pattern_ty]:
| pattern=or_pattern 'as' target=pattern_capture_target {
_PyAST_MatchAs(pattern, target->v.Name.id, EXTRA) }
| invalid_as_pattern
or_pattern[pattern_ty]:
| patterns[asdl_pattern_seq*]='|'.closed_pattern+ {
asdl_seq_LEN(patterns) == 1 ? asdl_seq_GET(patterns, 0) : _PyAST_MatchOr(patterns, EXTRA) }
closed_pattern[pattern_ty] (memo):
| literal_pattern
| capture_pattern
| wildcard_pattern
| value_pattern
| group_pattern
| sequence_pattern
| mapping_pattern
| class_pattern
# Literal patterns are used for equality and identity constraints
literal_pattern[pattern_ty]:
| value=signed_number !('+' | '-') { _PyAST_MatchValue(value, EXTRA) }
| value=complex_number { _PyAST_MatchValue(value, EXTRA) }
| value=strings { _PyAST_MatchValue(value, EXTRA) }
| 'None' { _PyAST_MatchSingleton(Py_None, EXTRA) }
| 'True' { _PyAST_MatchSingleton(Py_True, EXTRA) }
| 'False' { _PyAST_MatchSingleton(Py_False, EXTRA) }
# Literal expressions are used to restrict permitted mapping pattern keys
literal_expr[expr_ty]:
| signed_number !('+' | '-')
| complex_number
| strings
| 'None' { _PyAST_Constant(Py_None, NULL, EXTRA) }
| 'True' { _PyAST_Constant(Py_True, NULL, EXTRA) }
| 'False' { _PyAST_Constant(Py_False, NULL, EXTRA) }
complex_number[expr_ty]:
| real=signed_real_number '+' imag=imaginary_number {
_PyAST_BinOp(real, Add, imag, EXTRA) }
| real=signed_real_number '-' imag=imaginary_number {
_PyAST_BinOp(real, Sub, imag, EXTRA) }
signed_number[expr_ty]:
| NUMBER
| '-' number=NUMBER { _PyAST_UnaryOp(USub, number, EXTRA) }
signed_real_number[expr_ty]:
| real_number
| '-' real=real_number { _PyAST_UnaryOp(USub, real, EXTRA) }
real_number[expr_ty]:
| real=NUMBER { _PyPegen_ensure_real(p, real) }
imaginary_number[expr_ty]:
| imag=NUMBER { _PyPegen_ensure_imaginary(p, imag) }
capture_pattern[pattern_ty]:
| target=pattern_capture_target { _PyAST_MatchAs(NULL, target->v.Name.id, EXTRA) }
pattern_capture_target[expr_ty]:
| !"_" name=NAME !('.' | '(' | '=') {
_PyPegen_set_expr_context(p, name, Store) }
wildcard_pattern[pattern_ty]:
| "_" { _PyAST_MatchAs(NULL, NULL, EXTRA) }
value_pattern[pattern_ty]:
| attr=attr !('.' | '(' | '=') { _PyAST_MatchValue(attr, EXTRA) }
attr[expr_ty]:
| value=name_or_attr '.' attr=NAME {
_PyAST_Attribute(value, attr->v.Name.id, Load, EXTRA) }
name_or_attr[expr_ty]:
| attr
| NAME
group_pattern[pattern_ty]:
| '(' pattern=pattern ')' { pattern }
sequence_pattern[pattern_ty]:
| '[' patterns=maybe_sequence_pattern? ']' { _PyAST_MatchSequence(patterns, EXTRA) }
| '(' patterns=open_sequence_pattern? ')' { _PyAST_MatchSequence(patterns, EXTRA) }
open_sequence_pattern[asdl_seq*]:
| pattern=maybe_star_pattern ',' patterns=maybe_sequence_pattern? {
_PyPegen_seq_insert_in_front(p, pattern, patterns) }
maybe_sequence_pattern[asdl_seq*]:
| patterns=','.maybe_star_pattern+ ','? { patterns }
maybe_star_pattern[pattern_ty]:
| star_pattern
| pattern
star_pattern[pattern_ty] (memo):
| '*' target=pattern_capture_target {
_PyAST_MatchStar(target->v.Name.id, EXTRA) }
| '*' wildcard_pattern {
_PyAST_MatchStar(NULL, EXTRA) }
mapping_pattern[pattern_ty]:
| '{' '}' {
_PyAST_MatchMapping(NULL, NULL, NULL, EXTRA) }
| '{' rest=double_star_pattern ','? '}' {
_PyAST_MatchMapping(NULL, NULL, rest->v.Name.id, EXTRA) }
| '{' items=items_pattern ',' rest=double_star_pattern ','? '}' {
_PyAST_MatchMapping(
CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, items)),
CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, items)),
rest->v.Name.id,
EXTRA) }
| '{' items=items_pattern ','? '}' {
_PyAST_MatchMapping(
CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, items)),
CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, items)),
NULL,
EXTRA) }
items_pattern[asdl_seq*]:
| ','.key_value_pattern+
key_value_pattern[KeyPatternPair*]:
| key=(literal_expr | attr) ':' pattern=pattern {
_PyPegen_key_pattern_pair(p, key, pattern) }
double_star_pattern[expr_ty]:
| '**' target=pattern_capture_target { target }
class_pattern[pattern_ty]:
| cls=name_or_attr '(' ')' {
_PyAST_MatchClass(cls, NULL, NULL, NULL, EXTRA) }
| cls=name_or_attr '(' patterns=positional_patterns ','? ')' {
_PyAST_MatchClass(cls, patterns, NULL, NULL, EXTRA) }
| cls=name_or_attr '(' keywords=keyword_patterns ','? ')' {
_PyAST_MatchClass(
cls, NULL,
CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p,
CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, keywords)))),
CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, keywords)),
EXTRA) }
| cls=name_or_attr '(' patterns=positional_patterns ',' keywords=keyword_patterns ','? ')' {
_PyAST_MatchClass(
cls,
patterns,
CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p,
CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, keywords)))),
CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, keywords)),
EXTRA) }
| invalid_class_pattern
positional_patterns[asdl_pattern_seq*]:
| args[asdl_pattern_seq*]=','.pattern+ { args }
keyword_patterns[asdl_seq*]:
| ','.keyword_pattern+
keyword_pattern[KeyPatternPair*]:
| arg=NAME '=' value=pattern { _PyPegen_key_pattern_pair(p, arg, value) }
# Type statement
# ---------------
type_alias[stmt_ty]:
| "type" n=NAME t=[type_params] '=' b=expression {
CHECK_VERSION(stmt_ty, 12, "Type statement is",
_PyAST_TypeAlias(CHECK(expr_ty, _PyPegen_set_expr_context(p, n, Store)), t, b, EXTRA)) }
# Type parameter declaration
# --------------------------
type_params[asdl_type_param_seq*]: '[' t=type_param_seq ']' {
CHECK_VERSION(asdl_type_param_seq *, 12, "Type parameter lists are", t) }
type_param_seq[asdl_type_param_seq*]: a[asdl_type_param_seq*]=','.type_param+ [','] { a }
type_param[type_param_ty] (memo):
| a=NAME b=[type_param_bound] { _PyAST_TypeVar(a->v.Name.id, b, EXTRA) }
| '*' a=NAME colon=":" e=expression {
RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
? "cannot use constraints with TypeVarTuple"
: "cannot use bound with TypeVarTuple")
}
| '*' a=NAME { _PyAST_TypeVarTuple(a->v.Name.id, EXTRA) }
| '**' a=NAME colon=":" e=expression {
RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
? "cannot use constraints with ParamSpec"
: "cannot use bound with ParamSpec")
}
| '**' a=NAME { _PyAST_ParamSpec(a->v.Name.id, EXTRA) }
type_param_bound[expr_ty]: ":" e=expression { e }
# EXPRESSIONS
# -----------
expressions[expr_ty]:
| a=expression b=(',' c=expression { c })+ [','] {
_PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) }
| a=expression ',' { _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_singleton_seq(p, a)), Load, EXTRA) }
| expression
expression[expr_ty] (memo):
| invalid_expression
| invalid_legacy_expression
| a=disjunction 'if' b=disjunction 'else' c=expression { _PyAST_IfExp(b, a, c, EXTRA) }
| disjunction
| lambdef
yield_expr[expr_ty]:
| 'yield' 'from' a=expression { _PyAST_YieldFrom(a, EXTRA) }
| 'yield' a=[star_expressions] { _PyAST_Yield(a, EXTRA) }
star_expressions[expr_ty]:
| a=star_expression b=(',' c=star_expression { c })+ [','] {
_PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) }
| a=star_expression ',' { _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_singleton_seq(p, a)), Load, EXTRA) }
| star_expression
star_expression[expr_ty] (memo):
| '*' a=bitwise_or { _PyAST_Starred(a, Load, EXTRA) }
| expression
star_named_expressions[asdl_expr_seq*]: a[asdl_expr_seq*]=','.star_named_expression+ [','] { a }
star_named_expression[expr_ty]:
| '*' a=bitwise_or { _PyAST_Starred(a, Load, EXTRA) }
| named_expression
assignment_expression[expr_ty]:
| a=NAME ':=' ~ b=expression {
CHECK_VERSION(expr_ty, 8, "Assignment expressions are",
_PyAST_NamedExpr(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), b, EXTRA)) }
named_expression[expr_ty]:
| assignment_expression
| invalid_named_expression
| expression !':='
disjunction[expr_ty] (memo):
| a=conjunction b=('or' c=conjunction { c })+ { _PyAST_BoolOp(
Or,
CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)),
EXTRA) }
| conjunction
conjunction[expr_ty] (memo):
| a=inversion b=('and' c=inversion { c })+ { _PyAST_BoolOp(
And,
CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)),
EXTRA) }
| inversion
inversion[expr_ty] (memo):
| 'not' a=inversion { _PyAST_UnaryOp(Not, a, EXTRA) }
| comparison
# Comparison operators
# --------------------
comparison[expr_ty]:
| a=bitwise_or b=compare_op_bitwise_or_pair+ {
_PyAST_Compare(
a,
CHECK(asdl_int_seq*, _PyPegen_get_cmpops(p, b)),
CHECK(asdl_expr_seq*, _PyPegen_get_exprs(p, b)),
EXTRA) }
| bitwise_or
compare_op_bitwise_or_pair[CmpopExprPair*]:
| eq_bitwise_or
| noteq_bitwise_or
| lte_bitwise_or
| lt_bitwise_or
| gte_bitwise_or
| gt_bitwise_or
| notin_bitwise_or
| in_bitwise_or
| isnot_bitwise_or
| is_bitwise_or
eq_bitwise_or[CmpopExprPair*]: '==' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Eq, a) }
noteq_bitwise_or[CmpopExprPair*]:
| (tok='!=' { _PyPegen_check_barry_as_flufl(p, tok) ? NULL : tok}) a=bitwise_or {_PyPegen_cmpop_expr_pair(p, NotEq, a) }
lte_bitwise_or[CmpopExprPair*]: '<=' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, LtE, a) }
lt_bitwise_or[CmpopExprPair*]: '<' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Lt, a) }
gte_bitwise_or[CmpopExprPair*]: '>=' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, GtE, a) }
gt_bitwise_or[CmpopExprPair*]: '>' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Gt, a) }
notin_bitwise_or[CmpopExprPair*]: 'not' 'in' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, NotIn, a) }
in_bitwise_or[CmpopExprPair*]: 'in' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, In, a) }
isnot_bitwise_or[CmpopExprPair*]: 'is' 'not' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, IsNot, a) }
is_bitwise_or[CmpopExprPair*]: 'is' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Is, a) }
# Bitwise operators
# -----------------
bitwise_or[expr_ty]:
| a=bitwise_or '|' b=bitwise_xor { _PyAST_BinOp(a, BitOr, b, EXTRA) }
| bitwise_xor
bitwise_xor[expr_ty]:
| a=bitwise_xor '^' b=bitwise_and { _PyAST_BinOp(a, BitXor, b, EXTRA) }
| bitwise_and
bitwise_and[expr_ty]:
| a=bitwise_and '&' b=shift_expr { _PyAST_BinOp(a, BitAnd, b, EXTRA) }
| shift_expr
shift_expr[expr_ty]:
| a=shift_expr '<<' b=sum { _PyAST_BinOp(a, LShift, b, EXTRA) }
| a=shift_expr '>>' b=sum { _PyAST_BinOp(a, RShift, b, EXTRA) }
| sum
# Arithmetic operators
# --------------------
sum[expr_ty]:
| a=sum '+' b=term { _PyAST_BinOp(a, Add, b, EXTRA) }
| a=sum '-' b=term { _PyAST_BinOp(a, Sub, b, EXTRA) }
| term
term[expr_ty]:
| a=term '*' b=factor { _PyAST_BinOp(a, Mult, b, EXTRA) }
| a=term '/' b=factor { _PyAST_BinOp(a, Div, b, EXTRA) }
| a=term '//' b=factor { _PyAST_BinOp(a, FloorDiv, b, EXTRA) }
| a=term '%' b=factor { _PyAST_BinOp(a, Mod, b, EXTRA) }
| a=term '@' b=factor { CHECK_VERSION(expr_ty, 5, "The '@' operator is", _PyAST_BinOp(a, MatMult, b, EXTRA)) }
| factor
factor[expr_ty] (memo):
| '+' a=factor { _PyAST_UnaryOp(UAdd, a, EXTRA) }
| '-' a=factor { _PyAST_UnaryOp(USub, a, EXTRA) }
| '~' a=factor { _PyAST_UnaryOp(Invert, a, EXTRA) }
| power
power[expr_ty]:
| a=await_primary '**' b=factor { _PyAST_BinOp(a, Pow, b, EXTRA) }
| await_primary
# Primary elements
# ----------------
# Primary elements are things like "obj.something.something", "obj[something]", "obj(something)", "obj" ...
await_primary[expr_ty] (memo):
| AWAIT a=primary { CHECK_VERSION(expr_ty, 5, "Await expressions are", _PyAST_Await(a, EXTRA)) }
| primary
primary[expr_ty]:
| a=primary '.' b=NAME { _PyAST_Attribute(a, b->v.Name.id, Load, EXTRA) }
| a=primary b=genexp { _PyAST_Call(a, CHECK(asdl_expr_seq*, (asdl_expr_seq*)_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }
| a=primary '(' b=[arguments] ')' {
_PyAST_Call(a,
(b) ? ((expr_ty) b)->v.Call.args : NULL,
(b) ? ((expr_ty) b)->v.Call.keywords : NULL,
EXTRA) }
| a=primary '[' b=slices ']' { _PyAST_Subscript(a, b, Load, EXTRA) }
| atom
slices[expr_ty]:
| a=slice !',' { a }
| a[asdl_expr_seq*]=','.(slice | starred_expression)+ [','] { _PyAST_Tuple(a, Load, EXTRA) }
slice[expr_ty]:
| a=[expression] ':' b=[expression] c=[':' d=[expression] { d }] { _PyAST_Slice(a, b, c, EXTRA) }
| a=named_expression { a }
atom[expr_ty]:
| NAME
| 'True' { _PyAST_Constant(Py_True, NULL, EXTRA) }
| 'False' { _PyAST_Constant(Py_False, NULL, EXTRA) }
| 'None' { _PyAST_Constant(Py_None, NULL, EXTRA) }
| &(STRING|FSTRING_START) strings
| NUMBER
| &'(' (tuple | group | genexp)
| &'[' (list | listcomp)
| &'{' (dict | set | dictcomp | setcomp)
| '...' { _PyAST_Constant(Py_Ellipsis, NULL, EXTRA) }
group[expr_ty]:
| '(' a=(yield_expr | named_expression) ')' { a }
| invalid_group
# Lambda functions
# ----------------
lambdef[expr_ty]:
| 'lambda' a=[lambda_params] ':' b=expression {
_PyAST_Lambda((a) ? a : CHECK(arguments_ty, _PyPegen_empty_arguments(p)), b, EXTRA) }
lambda_params[arguments_ty]:
| invalid_lambda_parameters
| lambda_parameters
# lambda_parameters etc. duplicates parameters but without annotations
# or type comments, and if there's no comma after a parameter, we expect
# a colon, not a close parenthesis. (For more, see parameters above.)
#
lambda_parameters[arguments_ty]:
| a=lambda_slash_no_default b[asdl_arg_seq*]=lambda_param_no_default* c=lambda_param_with_default* d=[lambda_star_etc] {
CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, a, NULL, b, c, d)) }
| a=lambda_slash_with_default b=lambda_param_with_default* c=[lambda_star_etc] {
CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, NULL, a, NULL, b, c)) }
| a[asdl_arg_seq*]=lambda_param_no_default+ b=lambda_param_with_default* c=[lambda_star_etc] {
_PyPegen_make_arguments(p, NULL, NULL, a, b, c) }
| a=lambda_param_with_default+ b=[lambda_star_etc] { _PyPegen_make_arguments(p, NULL, NULL, NULL, a, b)}
| a=lambda_star_etc { _PyPegen_make_arguments(p, NULL, NULL, NULL, NULL, a) }
lambda_slash_no_default[asdl_arg_seq*]:
| a[asdl_arg_seq*]=lambda_param_no_default+ '/' ',' { a }
| a[asdl_arg_seq*]=lambda_param_no_default+ '/' &':' { a }
lambda_slash_with_default[SlashWithDefault*]:
| a=lambda_param_no_default* b=lambda_param_with_default+ '/' ',' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
| a=lambda_param_no_default* b=lambda_param_with_default+ '/' &':' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
lambda_star_etc[StarEtc*]:
| invalid_lambda_star_etc
| '*' a=lambda_param_no_default b=lambda_param_maybe_default* c=[lambda_kwds] {
_PyPegen_star_etc(p, a, b, c) }
| '*' ',' b=lambda_param_maybe_default+ c=[lambda_kwds] {
_PyPegen_star_etc(p, NULL, b, c) }
| a=lambda_kwds { _PyPegen_star_etc(p, NULL, NULL, a) }
lambda_kwds[arg_ty]:
| invalid_lambda_kwds
| '**' a=lambda_param_no_default { a }
lambda_param_no_default[arg_ty]:
| a=lambda_param ',' { a }
| a=lambda_param &':' { a }
lambda_param_with_default[NameDefaultPair*]:
| a=lambda_param c=default ',' { _PyPegen_name_default_pair(p, a, c, NULL) }
| a=lambda_param c=default &':' { _PyPegen_name_default_pair(p, a, c, NULL) }
lambda_param_maybe_default[NameDefaultPair*]:
| a=lambda_param c=default? ',' { _PyPegen_name_default_pair(p, a, c, NULL) }
| a=lambda_param c=default? &':' { _PyPegen_name_default_pair(p, a, c, NULL) }
lambda_param[arg_ty]: a=NAME { _PyAST_arg(a->v.Name.id, NULL, NULL, EXTRA) }
# LITERALS
# ========
fstring_middle[expr_ty]:
| fstring_replacement_field
| t=FSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
fstring_replacement_field[expr_ty]:
| '{' a=(yield_expr | star_expressions) debug_expr="="? conversion=[fstring_conversion] format=[fstring_full_format_spec] rbrace='}' {
_PyPegen_formatted_value(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
| invalid_replacement_field
fstring_conversion[ResultTokenWithMetadata*]:
| conv_token="!" conv=NAME { _PyPegen_check_fstring_conversion(p, conv_token, conv) }
fstring_full_format_spec[ResultTokenWithMetadata*]:
| colon=':' spec=fstring_format_spec* { _PyPegen_setup_full_format_spec(p, colon, (asdl_expr_seq *) spec, EXTRA) }
fstring_format_spec[expr_ty]:
| t=FSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
| fstring_replacement_field
fstring[expr_ty]:
| a=FSTRING_START b=fstring_middle* c=FSTRING_END { _PyPegen_joined_str(p, a, (asdl_expr_seq*)b, c) }
string[expr_ty]: s[Token*]=STRING { _PyPegen_constant_from_string(p, s) }
strings[expr_ty] (memo): a[asdl_expr_seq*]=(fstring|string)+ { _PyPegen_concatenate_strings(p, a, EXTRA) }
list[expr_ty]:
| '[' a=[star_named_expressions] ']' { _PyAST_List(a, Load, EXTRA) }
tuple[expr_ty]:
| '(' a=[y=star_named_expression ',' z=[star_named_expressions] { _PyPegen_seq_insert_in_front(p, y, z) } ] ')' {
_PyAST_Tuple(a, Load, EXTRA) }
set[expr_ty]: '{' a=star_named_expressions '}' { _PyAST_Set(a, EXTRA) }
# Dicts
# -----
dict[expr_ty]:
| '{' a=[double_starred_kvpairs] '}' {
_PyAST_Dict(
CHECK(asdl_expr_seq*, _PyPegen_get_keys(p, a)),
CHECK(asdl_expr_seq*, _PyPegen_get_values(p, a)),
EXTRA) }
| '{' invalid_double_starred_kvpairs '}'
double_starred_kvpairs[asdl_seq*]: a=','.double_starred_kvpair+ [','] { a }
double_starred_kvpair[KeyValuePair*]:
| '**' a=bitwise_or { _PyPegen_key_value_pair(p, NULL, a) }
| kvpair
kvpair[KeyValuePair*]: a=expression ':' b=expression { _PyPegen_key_value_pair(p, a, b) }
# Comprehensions & Generators
# ---------------------------
for_if_clauses[asdl_comprehension_seq*]:
| a[asdl_comprehension_seq*]=for_if_clause+ { a }
for_if_clause[comprehension_ty]:
| ASYNC 'for' a=star_targets 'in' ~ b=disjunction c[asdl_expr_seq*]=('if' z=disjunction { z })* {
CHECK_VERSION(comprehension_ty, 6, "Async comprehensions are", _PyAST_comprehension(a, b, c, 1, p->arena)) }
| 'for' a=star_targets 'in' ~ b=disjunction c[asdl_expr_seq*]=('if' z=disjunction { z })* {
_PyAST_comprehension(a, b, c, 0, p->arena) }
| invalid_for_target
listcomp[expr_ty]:
| '[' a=named_expression b=for_if_clauses ']' { _PyAST_ListComp(a, b, EXTRA) }
| invalid_comprehension
setcomp[expr_ty]:
| '{' a=named_expression b=for_if_clauses '}' { _PyAST_SetComp(a, b, EXTRA) }
| invalid_comprehension
genexp[expr_ty]:
| '(' a=( assignment_expression | expression !':=') b=for_if_clauses ')' { _PyAST_GeneratorExp(a, b, EXTRA) }
| invalid_comprehension
dictcomp[expr_ty]:
| '{' a=kvpair b=for_if_clauses '}' { _PyAST_DictComp(a->key, a->value, b, EXTRA) }
| invalid_dict_comprehension
# FUNCTION CALL ARGUMENTS
# =======================
arguments[expr_ty] (memo):
| a=args [','] &')' { a }
| invalid_arguments
args[expr_ty]:
| a[asdl_expr_seq*]=','.(starred_expression | ( assignment_expression | expression !':=') !'=')+ b=[',' k=kwargs {k}] {
_PyPegen_collect_call_seqs(p, a, b, EXTRA) }
| a=kwargs { _PyAST_Call(_PyPegen_dummy_name(p),
CHECK_NULL_ALLOWED(asdl_expr_seq*, _PyPegen_seq_extract_starred_exprs(p, a)),
CHECK_NULL_ALLOWED(asdl_keyword_seq*, _PyPegen_seq_delete_starred_exprs(p, a)),
EXTRA) }
kwargs[asdl_seq*]:
| a=','.kwarg_or_starred+ ',' b=','.kwarg_or_double_starred+ { _PyPegen_join_sequences(p, a, b) }
| ','.kwarg_or_starred+
| ','.kwarg_or_double_starred+
starred_expression[expr_ty]:
| invalid_starred_expression
| '*' a=expression { _PyAST_Starred(a, Load, EXTRA) }
kwarg_or_starred[KeywordOrStarred*]:
| invalid_kwarg
| a=NAME '=' b=expression {
_PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(a->v.Name.id, b, EXTRA)), 1) }
| a=starred_expression { _PyPegen_keyword_or_starred(p, a, 0) }
kwarg_or_double_starred[KeywordOrStarred*]:
| invalid_kwarg
| a=NAME '=' b=expression {
_PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(a->v.Name.id, b, EXTRA)), 1) }
| '**' a=expression { _PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(NULL, a, EXTRA)), 1) }
# ASSIGNMENT TARGETS
# ==================
# Generic targets
# ---------------
# NOTE: star_targets may contain *bitwise_or, targets may not.
star_targets[expr_ty]:
| a=star_target !',' { a }
| a=star_target b=(',' c=star_target { c })* [','] {
_PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Store, EXTRA) }
star_targets_list_seq[asdl_expr_seq*]: a[asdl_expr_seq*]=','.star_target+ [','] { a }
star_targets_tuple_seq[asdl_expr_seq*]:
| a=star_target b=(',' c=star_target { c })+ [','] { (asdl_expr_seq*) _PyPegen_seq_insert_in_front(p, a, b) }
| a=star_target ',' { (asdl_expr_seq*) _PyPegen_singleton_seq(p, a) }
star_target[expr_ty] (memo):
| '*' a=(!'*' star_target) {
_PyAST_Starred(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), Store, EXTRA) }
| target_with_star_atom
target_with_star_atom[expr_ty] (memo):
| a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Store, EXTRA) }
| a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Store, EXTRA) }
| star_atom
star_atom[expr_ty]:
| a=NAME { _PyPegen_set_expr_context(p, a, Store) }
| '(' a=target_with_star_atom ')' { _PyPegen_set_expr_context(p, a, Store) }
| '(' a=[star_targets_tuple_seq] ')' { _PyAST_Tuple(a, Store, EXTRA) }
| '[' a=[star_targets_list_seq] ']' { _PyAST_List(a, Store, EXTRA) }
single_target[expr_ty]:
| single_subscript_attribute_target
| a=NAME { _PyPegen_set_expr_context(p, a, Store) }
| '(' a=single_target ')' { a }
single_subscript_attribute_target[expr_ty]:
| a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Store, EXTRA) }
| a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Store, EXTRA) }
t_primary[expr_ty]:
| a=t_primary '.' b=NAME &t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Load, EXTRA) }
| a=t_primary '[' b=slices ']' &t_lookahead { _PyAST_Subscript(a, b, Load, EXTRA) }
| a=t_primary b=genexp &t_lookahead {
_PyAST_Call(a, CHECK(asdl_expr_seq*, (asdl_expr_seq*)_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }
| a=t_primary '(' b=[arguments] ')' &t_lookahead {
_PyAST_Call(a,
(b) ? ((expr_ty) b)->v.Call.args : NULL,
(b) ? ((expr_ty) b)->v.Call.keywords : NULL,
EXTRA) }
| a=atom &t_lookahead { a }
t_lookahead: '(' | '[' | '.'
# Targets for del statements
# --------------------------
del_targets[asdl_expr_seq*]: a[asdl_expr_seq*]=','.del_target+ [','] { a }
del_target[expr_ty] (memo):
| a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Del, EXTRA) }
| a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Del, EXTRA) }
| del_t_atom
del_t_atom[expr_ty]:
| a=NAME { _PyPegen_set_expr_context(p, a, Del) }
| '(' a=del_target ')' { _PyPegen_set_expr_context(p, a, Del) }
| '(' a=[del_targets] ')' { _PyAST_Tuple(a, Del, EXTRA) }
| '[' a=[del_targets] ']' { _PyAST_List(a, Del, EXTRA) }
# TYPING ELEMENTS
# ---------------
# type_expressions allow */** but ignore them
type_expressions[asdl_expr_seq*]:
| a=','.expression+ ',' '*' b=expression ',' '**' c=expression {
(asdl_expr_seq*)_PyPegen_seq_append_to_end(
p,
CHECK(asdl_seq*, _PyPegen_seq_append_to_end(p, a, b)),
c) }
| a=','.expression+ ',' '*' b=expression { (asdl_expr_seq*)_PyPegen_seq_append_to_end(p, a, b) }
| a=','.expression+ ',' '**' b=expression { (asdl_expr_seq*)_PyPegen_seq_append_to_end(p, a, b) }
| '*' a=expression ',' '**' b=expression {
(asdl_expr_seq*)_PyPegen_seq_append_to_end(
p,
CHECK(asdl_seq*, _PyPegen_singleton_seq(p, a)),
b) }
| '*' a=expression { (asdl_expr_seq*)_PyPegen_singleton_seq(p, a) }
| '**' a=expression { (asdl_expr_seq*)_PyPegen_singleton_seq(p, a) }
| a[asdl_expr_seq*]=','.expression+ {a}
func_type_comment[Token*]:
| NEWLINE t=TYPE_COMMENT &(NEWLINE INDENT) { t } # Must be followed by indented block
| invalid_double_type_comments
| TYPE_COMMENT
# ========================= END OF THE GRAMMAR ===========================
# ========================= START OF INVALID RULES =======================
# From here on, there are rules for invalid syntax with specialised error messages
invalid_arguments:
| a=args ',' '*' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "iterable argument unpacking follows keyword argument unpacking") }
| a=expression b=for_if_clauses ',' [args | expression for_if_clauses] {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
| a=NAME b='=' expression for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
| (args ',')? a=NAME b='=' &(',' | ')') {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected argument value expression")}
| a=args b=for_if_clauses { _PyPegen_nonparen_genexp_in_call(p, a, b) }
| args ',' a=expression b=for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
| a=args ',' args { _PyPegen_arguments_parsing_error(p, a) }
invalid_kwarg:
| a[Token*]=('True'|'False'|'None') b='=' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to %s", PyBytes_AS_STRING(a->bytes)) }
| a=NAME b='=' expression for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
| !(NAME '=') a=expression b='=' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(
a, b, "expression cannot contain assignment, perhaps you meant \"==\"?") }
| a='**' expression '=' b=expression {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to keyword argument unpacking") }
# IMPORTANT: Note that the "_without_invalid" suffix causes the rule to not call invalid rules under it
expression_without_invalid[expr_ty]:
| a=disjunction 'if' b=disjunction 'else' c=expression { _PyAST_IfExp(b, a, c, EXTRA) }
| disjunction
| lambdef
invalid_legacy_expression:
| a=NAME !'(' b=star_expressions {
_PyPegen_check_legacy_stmt(p, a) ? RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b,
"Missing parentheses in call to '%U'. Did you mean %U(...)?", a->v.Name.id, a->v.Name.id) : NULL}
invalid_expression:
# !(NAME STRING) is not matched so we don't show this error with some invalid string prefixes like: kf"dsfsdf"
# Soft keywords need to also be ignored because they can be parsed as NAME NAME
| !(NAME STRING | SOFT_KEYWORD) a=disjunction b=expression_without_invalid {
_PyPegen_check_legacy_stmt(p, a) ? NULL : p->tokens[p->mark-1]->level == 0 ? NULL :
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Perhaps you forgot a comma?") }
| a=disjunction 'if' b=disjunction !('else'|':') { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected 'else' after 'if' expression") }
| a='lambda' [lambda_params] b=':' &(FSTRING_MIDDLE | fstring_replacement_field) {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "f-string: lambda expressions are not allowed without parentheses") }
invalid_named_expression(memo):
| a=expression ':=' expression {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
a, "cannot use assignment expressions with %s", _PyPegen_get_expr_name(a)) }
| a=NAME '=' b=bitwise_or !('='|':=') {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?") }
| !(list|tuple|genexp|'True'|'None'|'False') a=bitwise_or b='=' bitwise_or !('='|':=') {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot assign to %s here. Maybe you meant '==' instead of '='?",
_PyPegen_get_expr_name(a)) }
invalid_assignment:
| a=invalid_ann_assign_target ':' expression {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
a,
"only single target (not %s) can be annotated",
_PyPegen_get_expr_name(a)
)}
| a=star_named_expression ',' star_named_expressions* ':' expression {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "only single target (not tuple) can be annotated") }
| a=expression ':' expression {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "illegal target for annotation") }
| (star_targets '=')* a=star_expressions '=' {
RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) }
| (star_targets '=')* a=yield_expr '=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "assignment to yield expression not possible") }
| a=star_expressions augassign (yield_expr | star_expressions) {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
a,
"'%s' is an illegal expression for augmented assignment",
_PyPegen_get_expr_name(a)
)}
invalid_ann_assign_target[expr_ty]:
| list
| tuple
| '(' a=invalid_ann_assign_target ')' { a }
invalid_del_stmt:
| 'del' a=star_expressions {
RAISE_SYNTAX_ERROR_INVALID_TARGET(DEL_TARGETS, a) }
invalid_block:
| NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block") }
invalid_comprehension:
| ('[' | '(' | '{') a=starred_expression for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "iterable unpacking cannot be used in comprehension") }
| ('[' | '{') a=star_named_expression ',' b=star_named_expressions for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, PyPegen_last_item(b, expr_ty),
"did you forget parentheses around the comprehension target?") }
| ('[' | '{') a=star_named_expression b=',' for_if_clauses {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "did you forget parentheses around the comprehension target?") }
invalid_dict_comprehension:
| '{' a='**' bitwise_or for_if_clauses '}' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "dict unpacking cannot be used in dict comprehension") }
invalid_parameters:
| a="/" ',' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "at least one argument must precede /") }
| (slash_no_default | slash_with_default) param_maybe_default* a='/' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
| slash_no_default? param_no_default* invalid_parameters_helper a=param_no_default {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
| param_no_default* a='(' param_no_default+ ','? b=')' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Function parameters cannot be parenthesized") }
| (slash_no_default | slash_with_default)? param_maybe_default* '*' (',' | param_no_default) param_maybe_default* a='/' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ must be ahead of *") }
| param_maybe_default+ '/' a='*' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected comma between / and *") }
invalid_default:
| a='=' &(')'|',') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected default value expression") }
invalid_star_etc:
| a='*' (')' | ',' (')' | '**')) { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "named arguments must follow bare *") }
| '*' ',' TYPE_COMMENT { RAISE_SYNTAX_ERROR("bare * has associated type comment") }
| '*' param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-positional argument cannot have default value") }
| '*' (param_no_default | ',') param_maybe_default* a='*' (param_no_default | ',') {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "* argument may appear only once") }
invalid_kwds:
| '**' param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-keyword argument cannot have default value") }
| '**' param ',' a=param { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
| '**' param ',' a[Token*]=('*'|'**'|'/') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
invalid_parameters_helper: # This is only there to avoid type errors
| a=slash_with_default { _PyPegen_singleton_seq(p, a) }
| param_with_default+
invalid_lambda_parameters:
| a="/" ',' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "at least one argument must precede /") }
| (lambda_slash_no_default | lambda_slash_with_default) lambda_param_maybe_default* a='/' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
| lambda_slash_no_default? lambda_param_no_default* invalid_lambda_parameters_helper a=lambda_param_no_default {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
| lambda_param_no_default* a='(' ','.lambda_param+ ','? b=')' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Lambda expression parameters cannot be parenthesized") }
| (lambda_slash_no_default | lambda_slash_with_default)? lambda_param_maybe_default* '*' (',' | lambda_param_no_default) lambda_param_maybe_default* a='/' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ must be ahead of *") }
| lambda_param_maybe_default+ '/' a='*' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected comma between / and *") }
invalid_lambda_parameters_helper:
| a=lambda_slash_with_default { _PyPegen_singleton_seq(p, a) }
| lambda_param_with_default+
invalid_lambda_star_etc:
| '*' (':' | ',' (':' | '**')) { RAISE_SYNTAX_ERROR("named arguments must follow bare *") }
| '*' lambda_param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-positional argument cannot have default value") }
| '*' (lambda_param_no_default | ',') lambda_param_maybe_default* a='*' (lambda_param_no_default | ',') {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "* argument may appear only once") }
invalid_lambda_kwds:
| '**' lambda_param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-keyword argument cannot have default value") }
| '**' lambda_param ',' a=lambda_param { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
| '**' lambda_param ',' a[Token*]=('*'|'**'|'/') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
invalid_double_type_comments:
| TYPE_COMMENT NEWLINE TYPE_COMMENT NEWLINE INDENT {
RAISE_SYNTAX_ERROR("Cannot have two type comments on def") }
invalid_with_item:
| expression 'as' a=expression &(',' | ')' | ':') {
RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) }
invalid_for_target:
| ASYNC? 'for' a=star_expressions {
RAISE_SYNTAX_ERROR_INVALID_TARGET(FOR_TARGETS, a) }
invalid_group:
| '(' a=starred_expression ')' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use starred expression here") }
| '(' a='**' expression ')' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use double starred expression here") }
invalid_import:
| a='import' dotted_name 'from' dotted_name {
RAISE_SYNTAX_ERROR_STARTING_FROM(a, "Did you mean to use 'from ... import ...' instead?") }
invalid_import_from_targets:
| import_from_as_names ',' NEWLINE {
RAISE_SYNTAX_ERROR("trailing comma not allowed without surrounding parentheses") }
invalid_with_stmt:
| [ASYNC] 'with' ','.(expression ['as' star_target])+ NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| [ASYNC] 'with' '(' ','.(expressions ['as' star_target])+ ','? ')' NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
invalid_with_stmt_indent:
| [ASYNC] a='with' ','.(expression ['as' star_target])+ ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'with' statement on line %d", a->lineno) }
| [ASYNC] a='with' '(' ','.(expressions ['as' star_target])+ ','? ')' ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'with' statement on line %d", a->lineno) }
invalid_try_stmt:
| a='try' ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'try' statement on line %d", a->lineno) }
| 'try' ':' block !('except' | 'finally') { RAISE_SYNTAX_ERROR("expected 'except' or 'finally' block") }
| 'try' ':' block* except_block+ a='except' b='*' expression ['as' NAME] ':' {
RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot have both 'except' and 'except*' on the same 'try'") }
| 'try' ':' block* except_star_block+ a='except' [expression ['as' NAME]] ':' {
RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot have both 'except' and 'except*' on the same 'try'") }
invalid_except_stmt:
| 'except' '*'? a=expression ',' expressions ['as' NAME ] ':' {
RAISE_SYNTAX_ERROR_STARTING_FROM(a, "multiple exception types must be parenthesized") }
| a='except' '*'? expression ['as' NAME ] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| a='except' NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| a='except' '*' (NEWLINE | ':') { RAISE_SYNTAX_ERROR("expected one or more exception types") }
invalid_finally_stmt:
| a='finally' ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'finally' statement on line %d", a->lineno) }
invalid_except_stmt_indent:
| a='except' expression ['as' NAME ] ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'except' statement on line %d", a->lineno) }
| a='except' ':' NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block after 'except' statement on line %d", a->lineno) }
invalid_except_star_stmt_indent:
| a='except' '*' expression ['as' NAME ] ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'except*' statement on line %d", a->lineno) }
invalid_match_stmt:
| "match" subject_expr NEWLINE { CHECK_VERSION(void*, 10, "Pattern matching is", RAISE_SYNTAX_ERROR("expected ':'") ) }
| a="match" subject=subject_expr ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'match' statement on line %d", a->lineno) }
invalid_case_block:
| "case" patterns guard? NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| a="case" patterns guard? ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'case' statement on line %d", a->lineno) }
invalid_as_pattern:
| or_pattern 'as' a="_" { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use '_' as a target") }
| or_pattern 'as' !NAME a=expression { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "invalid pattern target") }
invalid_class_pattern:
| name_or_attr '(' a=invalid_class_argument_pattern { RAISE_SYNTAX_ERROR_KNOWN_RANGE(
PyPegen_first_item(a, pattern_ty),
PyPegen_last_item(a, pattern_ty),
"positional patterns follow keyword patterns") }
invalid_class_argument_pattern[asdl_pattern_seq*]:
| [positional_patterns ','] keyword_patterns ',' a=positional_patterns { a }
invalid_if_stmt:
| 'if' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| a='if' a=named_expression ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'if' statement on line %d", a->lineno) }
invalid_elif_stmt:
| 'elif' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| a='elif' named_expression ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'elif' statement on line %d", a->lineno) }
invalid_else_stmt:
| a='else' ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'else' statement on line %d", a->lineno) }
invalid_while_stmt:
| 'while' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| a='while' named_expression ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'while' statement on line %d", a->lineno) }
invalid_for_stmt:
| [ASYNC] 'for' star_targets 'in' star_expressions NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| [ASYNC] a='for' star_targets 'in' star_expressions ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after 'for' statement on line %d", a->lineno) }
invalid_def_raw:
| [ASYNC] a='def' NAME '(' [params] ')' ['->' expression] ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after function definition on line %d", a->lineno) }
invalid_class_def_raw:
| 'class' NAME ['(' [arguments] ')'] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
| a='class' NAME ['(' [arguments] ')'] ':' NEWLINE !INDENT {
RAISE_INDENTATION_ERROR("expected an indented block after class definition on line %d", a->lineno) }
invalid_double_starred_kvpairs:
| ','.double_starred_kvpair+ ',' invalid_kvpair
| expression ':' a='*' bitwise_or { RAISE_SYNTAX_ERROR_STARTING_FROM(a, "cannot use a starred expression in a dictionary value") }
| expression a=':' &('}'|',') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expression expected after dictionary key and ':'") }
invalid_kvpair:
| a=expression !(':') {
RAISE_ERROR_KNOWN_LOCATION(p, PyExc_SyntaxError, a->lineno, a->end_col_offset - 1, a->end_lineno, -1, "':' expected after dictionary key") }
| expression ':' a='*' bitwise_or { RAISE_SYNTAX_ERROR_STARTING_FROM(a, "cannot use a starred expression in a dictionary value") }
| expression a=':' &('}'|',') {RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expression expected after dictionary key and ':'") }
invalid_starred_expression:
| a='*' expression '=' b=expression { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to iterable argument unpacking") }
invalid_replacement_field:
| '{' a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '='") }
| '{' a='!' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '!'") }
| '{' a=':' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before ':'") }
| '{' a='}' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '}'") }
| '{' !(yield_expr | star_expressions) { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting a valid expression after '{'")}
| '{' (yield_expr | star_expressions) !('=' | '!' | ':' | '}') {
PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '=', or '!', or ':', or '}'") }
| '{' (yield_expr | star_expressions) '=' !('!' | ':' | '}') {
PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '!', or ':', or '}'") }
| '{' (yield_expr | star_expressions) '='? invalid_conversion_character
| '{' (yield_expr | star_expressions) '='? ['!' NAME] !(':' | '}') {
PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting ':' or '}'") }
| '{' (yield_expr | star_expressions) '='? ['!' NAME] ':' fstring_format_spec* !'}' {
PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}', or format specs") }
| '{' (yield_expr | star_expressions) '='? ['!' NAME] !'}' {
PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}'") }
invalid_conversion_character:
| '!' &(':' | '}') { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: missing conversion character") }
| '!' !NAME { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: invalid conversion character") }
|