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1# PEG grammar for Python
2
3@trailer '''
4void *
5_PyPegen_parse(Parser *p)
6{
7    // Initialize keywords
8    p->keywords = reserved_keywords;
9    p->n_keyword_lists = n_keyword_lists;
10    p->soft_keywords = soft_keywords;
11
12    // Run parser
13    void *result = NULL;
14    if (p->start_rule == Py_file_input) {
15        result = file_rule(p);
16    } else if (p->start_rule == Py_single_input) {
17        result = interactive_rule(p);
18    } else if (p->start_rule == Py_eval_input) {
19        result = eval_rule(p);
20    } else if (p->start_rule == Py_func_type_input) {
21        result = func_type_rule(p);
22    }
23
24    return result;
25}
26'''
27
28# ========================= START OF THE GRAMMAR =========================
29
30# General grammatical elements and rules:
31#
32# * Strings with double quotes (") denote SOFT KEYWORDS
33# * Strings with single quotes (') denote KEYWORDS
34# * Upper case names (NAME) denote tokens in the Grammar/Tokens file
35# * Rule names starting with "invalid_" are used for specialized syntax errors
36#     - These rules are NOT used in the first pass of the parser.
37#     - Only if the first pass fails to parse, a second pass including the invalid
38#       rules will be executed.
39#     - If the parser fails in the second phase with a generic syntax error, the
40#       location of the generic failure of the first pass will be used (this avoids
41#       reporting incorrect locations due to the invalid rules).
42#     - The order of the alternatives involving invalid rules matter
43#       (like any rule in PEG).
44#
45# Grammar Syntax (see PEP 617 for more information):
46#
47# rule_name: expression
48#   Optionally, a type can be included right after the rule name, which
49#   specifies the return type of the C or Python function corresponding to the
50#   rule:
51# rule_name[return_type]: expression
52#   If the return type is omitted, then a void * is returned in C and an Any in
53#   Python.
54# e1 e2
55#   Match e1, then match e2.
56# e1 | e2
57#   Match e1 or e2.
58#   The first alternative can also appear on the line after the rule name for
59#   formatting purposes. In that case, a | must be used before the first
60#   alternative, like so:
61#       rule_name[return_type]:
62#            | first_alt
63#            | second_alt
64# ( e )
65#   Match e (allows also to use other operators in the group like '(e)*')
66# [ e ] or e?
67#   Optionally match e.
68# e*
69#   Match zero or more occurrences of e.
70# e+
71#   Match one or more occurrences of e.
72# s.e+
73#   Match one or more occurrences of e, separated by s. The generated parse tree
74#   does not include the separator. This is otherwise identical to (e (s e)*).
75# &e
76#   Succeed if e can be parsed, without consuming any input.
77# !e
78#   Fail if e can be parsed, without consuming any input.
79# ~
80#   Commit to the current alternative, even if it fails to parse.
81# &&e
82#   Eager parse e. The parser will not backtrack and will immediately
83#   fail with SyntaxError if e cannot be parsed.
84#
85
86# STARTING RULES
87# ==============
88
89file[mod_ty]: a=[statements] ENDMARKER { _PyPegen_make_module(p, a) }
90interactive[mod_ty]: a=statement_newline { _PyAST_Interactive(a, p->arena) }
91eval[mod_ty]: a=expressions NEWLINE* ENDMARKER { _PyAST_Expression(a, p->arena) }
92func_type[mod_ty]: '(' a=[type_expressions] ')' '->' b=expression NEWLINE* ENDMARKER { _PyAST_FunctionType(a, b, p->arena) }
93
94# GENERAL STATEMENTS
95# ==================
96
97statements[asdl_stmt_seq*]: a=statement+ { (asdl_stmt_seq*)_PyPegen_seq_flatten(p, a) }
98
99statement[asdl_stmt_seq*]: a=compound_stmt { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a) } | a[asdl_stmt_seq*]=simple_stmts { a }
100
101statement_newline[asdl_stmt_seq*]:
102    | a=compound_stmt NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a) }
103    | simple_stmts
104    | NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, CHECK(stmt_ty, _PyAST_Pass(EXTRA))) }
105    | ENDMARKER { _PyPegen_interactive_exit(p) }
106
107simple_stmts[asdl_stmt_seq*]:
108    | a=simple_stmt !';' NEWLINE { (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a) } # Not needed, there for speedup
109    | a[asdl_stmt_seq*]=';'.simple_stmt+ [';'] NEWLINE { a }
110
111# NOTE: assignment MUST precede expression, else parsing a simple assignment
112# will throw a SyntaxError.
113simple_stmt[stmt_ty] (memo):
114    | assignment
115    | &"type" type_alias
116    | e=star_expressions { _PyAST_Expr(e, EXTRA) }
117    | &'return' return_stmt
118    | &('import' | 'from') import_stmt
119    | &'raise' raise_stmt
120    | 'pass' { _PyAST_Pass(EXTRA) }
121    | &'del' del_stmt
122    | &'yield' yield_stmt
123    | &'assert' assert_stmt
124    | 'break' { _PyAST_Break(EXTRA) }
125    | 'continue' { _PyAST_Continue(EXTRA) }
126    | &'global' global_stmt
127    | &'nonlocal' nonlocal_stmt
128
129compound_stmt[stmt_ty]:
130    | &('def' | '@' | 'async') function_def
131    | &'if' if_stmt
132    | &('class' | '@') class_def
133    | &('with' | 'async') with_stmt
134    | &('for' | 'async') for_stmt
135    | &'try' try_stmt
136    | &'while' while_stmt
137    | match_stmt
138
139# SIMPLE STATEMENTS
140# =================
141
142# NOTE: annotated_rhs may start with 'yield'; yield_expr must start with 'yield'
143assignment[stmt_ty]:
144    | a=NAME ':' b=expression c=['=' d=annotated_rhs { d }] {
145        CHECK_VERSION(
146            stmt_ty,
147            6,
148            "Variable annotation syntax is",
149            _PyAST_AnnAssign(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), b, c, 1, EXTRA)
150        ) }
151    | a=('(' b=single_target ')' { b }
152         | single_subscript_attribute_target) ':' b=expression c=['=' d=annotated_rhs { d }] {
153        CHECK_VERSION(stmt_ty, 6, "Variable annotations syntax is", _PyAST_AnnAssign(a, b, c, 0, EXTRA)) }
154    | a[asdl_expr_seq*]=(z=star_targets '=' { z })+ b=(yield_expr | star_expressions) !'=' tc=[TYPE_COMMENT] {
155         _PyAST_Assign(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
156    | a=single_target b=augassign ~ c=(yield_expr | star_expressions) {
157         _PyAST_AugAssign(a, b->kind, c, EXTRA) }
158    | invalid_assignment
159
160annotated_rhs[expr_ty]: yield_expr | star_expressions
161
162augassign[AugOperator*]:
163    | '+=' { _PyPegen_augoperator(p, Add) }
164    | '-=' { _PyPegen_augoperator(p, Sub) }
165    | '*=' { _PyPegen_augoperator(p, Mult) }
166    | '@=' { CHECK_VERSION(AugOperator*, 5, "The '@' operator is", _PyPegen_augoperator(p, MatMult)) }
167    | '/=' { _PyPegen_augoperator(p, Div) }
168    | '%=' { _PyPegen_augoperator(p, Mod) }
169    | '&=' { _PyPegen_augoperator(p, BitAnd) }
170    | '|=' { _PyPegen_augoperator(p, BitOr) }
171    | '^=' { _PyPegen_augoperator(p, BitXor) }
172    | '<<=' { _PyPegen_augoperator(p, LShift) }
173    | '>>=' { _PyPegen_augoperator(p, RShift) }
174    | '**=' { _PyPegen_augoperator(p, Pow) }
175    | '//=' { _PyPegen_augoperator(p, FloorDiv) }
176
177return_stmt[stmt_ty]:
178    | 'return' a=[star_expressions] { _PyAST_Return(a, EXTRA) }
179
180raise_stmt[stmt_ty]:
181    | 'raise' a=expression b=['from' z=expression { z }] { _PyAST_Raise(a, b, EXTRA) }
182    | 'raise' { _PyAST_Raise(NULL, NULL, EXTRA) }
183
184global_stmt[stmt_ty]: 'global' a[asdl_expr_seq*]=','.NAME+ {
185    _PyAST_Global(CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p, a)), EXTRA) }
186
187nonlocal_stmt[stmt_ty]: 'nonlocal' a[asdl_expr_seq*]=','.NAME+ {
188    _PyAST_Nonlocal(CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p, a)), EXTRA) }
189
190del_stmt[stmt_ty]:
191    | 'del' a=del_targets &(';' | NEWLINE) { _PyAST_Delete(a, EXTRA) }
192    | invalid_del_stmt
193
194yield_stmt[stmt_ty]: y=yield_expr { _PyAST_Expr(y, EXTRA) }
195
196assert_stmt[stmt_ty]: 'assert' a=expression b=[',' z=expression { z }] { _PyAST_Assert(a, b, EXTRA) }
197
198import_stmt[stmt_ty]:
199    | invalid_import
200    | import_name
201    | import_from
202
203# Import statements
204# -----------------
205
206import_name[stmt_ty]: 'import' a=dotted_as_names { _PyAST_Import(a, EXTRA) }
207# note below: the ('.' | '...') is necessary because '...' is tokenized as ELLIPSIS
208import_from[stmt_ty]:
209    | 'from' a=('.' | '...')* b=dotted_name 'import' c=import_from_targets {
210        _PyAST_ImportFrom(b->v.Name.id, c, _PyPegen_seq_count_dots(a), EXTRA) }
211    | 'from' a=('.' | '...')+ 'import' b=import_from_targets {
212        _PyAST_ImportFrom(NULL, b, _PyPegen_seq_count_dots(a), EXTRA) }
213import_from_targets[asdl_alias_seq*]:
214    | '(' a=import_from_as_names [','] ')' { a }
215    | import_from_as_names !','
216    | '*' { (asdl_alias_seq*)_PyPegen_singleton_seq(p, CHECK(alias_ty, _PyPegen_alias_for_star(p, EXTRA))) }
217    | invalid_import_from_targets
218import_from_as_names[asdl_alias_seq*]:
219    | a[asdl_alias_seq*]=','.import_from_as_name+ { a }
220import_from_as_name[alias_ty]:
221    | a=NAME b=['as' z=NAME { z }] { _PyAST_alias(a->v.Name.id,
222                                               (b) ? ((expr_ty) b)->v.Name.id : NULL,
223                                               EXTRA) }
224dotted_as_names[asdl_alias_seq*]:
225    | a[asdl_alias_seq*]=','.dotted_as_name+ { a }
226dotted_as_name[alias_ty]:
227    | a=dotted_name b=['as' z=NAME { z }] { _PyAST_alias(a->v.Name.id,
228                                                      (b) ? ((expr_ty) b)->v.Name.id : NULL,
229                                                      EXTRA) }
230dotted_name[expr_ty]:
231    | a=dotted_name '.' b=NAME { _PyPegen_join_names_with_dot(p, a, b) }
232    | NAME
233
234# COMPOUND STATEMENTS
235# ===================
236
237# Common elements
238# ---------------
239
240block[asdl_stmt_seq*] (memo):
241    | NEWLINE INDENT a=statements DEDENT { a }
242    | simple_stmts
243    | invalid_block
244
245decorators[asdl_expr_seq*]: a[asdl_expr_seq*]=('@' f=named_expression NEWLINE { f })+ { a }
246
247# Class definitions
248# -----------------
249
250class_def[stmt_ty]:
251    | a=decorators b=class_def_raw { _PyPegen_class_def_decorators(p, a, b) }
252    | class_def_raw
253
254class_def_raw[stmt_ty]:
255    | invalid_class_def_raw
256    | 'class' a=NAME t=[type_params] b=['(' z=[arguments] ')' { z }] ':' c=block {
257        _PyAST_ClassDef(a->v.Name.id,
258                     (b) ? ((expr_ty) b)->v.Call.args : NULL,
259                     (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
260                     c, NULL, t, EXTRA) }
261
262# Function definitions
263# --------------------
264
265function_def[stmt_ty]:
266    | d=decorators f=function_def_raw { _PyPegen_function_def_decorators(p, d, f) }
267    | function_def_raw
268
269function_def_raw[stmt_ty]:
270    | invalid_def_raw
271    | 'def' n=NAME t=[type_params] '(' params=[params] ')' a=['->' z=expression { z }] ':' tc=[func_type_comment] b=block {
272        _PyAST_FunctionDef(n->v.Name.id,
273                        (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
274                        b, NULL, a, NEW_TYPE_COMMENT(p, tc), t, EXTRA) }
275    | 'async' 'def' n=NAME t=[type_params] '(' params=[params] ')' a=['->' z=expression { z }] ':' tc=[func_type_comment] b=block {
276        CHECK_VERSION(
277            stmt_ty,
278            5,
279            "Async functions are",
280            _PyAST_AsyncFunctionDef(n->v.Name.id,
281                            (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
282                            b, NULL, a, NEW_TYPE_COMMENT(p, tc), t, EXTRA)
283        ) }
284
285# Function parameters
286# -------------------
287
288params[arguments_ty]:
289    | invalid_parameters
290    | parameters
291
292parameters[arguments_ty]:
293    | a=slash_no_default b[asdl_arg_seq*]=param_no_default* c=param_with_default* d=[star_etc] {
294        CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, a, NULL, b, c, d)) }
295    | a=slash_with_default b=param_with_default* c=[star_etc] {
296        CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, NULL, a, NULL, b, c)) }
297    | a[asdl_arg_seq*]=param_no_default+ b=param_with_default* c=[star_etc] {
298        _PyPegen_make_arguments(p, NULL, NULL, a, b, c) }
299    | a=param_with_default+ b=[star_etc] { _PyPegen_make_arguments(p, NULL, NULL, NULL, a, b)}
300    | a=star_etc { _PyPegen_make_arguments(p, NULL, NULL, NULL, NULL, a) }
301
302# Some duplication here because we can't write (',' | &')'),
303# which is because we don't support empty alternatives (yet).
304
305slash_no_default[asdl_arg_seq*]:
306    | a[asdl_arg_seq*]=param_no_default+ '/' ',' { a }
307    | a[asdl_arg_seq*]=param_no_default+ '/' &')' { a }
308slash_with_default[SlashWithDefault*]:
309    | a=param_no_default* b=param_with_default+ '/' ',' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
310    | a=param_no_default* b=param_with_default+ '/' &')' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
311
312star_etc[StarEtc*]:
313    | invalid_star_etc
314    | '*' a=param_no_default b=param_maybe_default* c=[kwds] {
315        _PyPegen_star_etc(p, a, b, c) }
316    | '*' a=param_no_default_star_annotation b=param_maybe_default* c=[kwds] {
317        _PyPegen_star_etc(p, a, b, c) }
318    | '*' ',' b=param_maybe_default+ c=[kwds] {
319        _PyPegen_star_etc(p, NULL, b, c) }
320    | a=kwds { _PyPegen_star_etc(p, NULL, NULL, a) }
321
322kwds[arg_ty]:
323    | invalid_kwds
324    | '**' a=param_no_default { a }
325
326# One parameter.  This *includes* a following comma and type comment.
327#
328# There are three styles:
329# - No default
330# - With default
331# - Maybe with default
332#
333# There are two alternative forms of each, to deal with type comments:
334# - Ends in a comma followed by an optional type comment
335# - No comma, optional type comment, must be followed by close paren
336# The latter form is for a final parameter without trailing comma.
337#
338
339param_no_default[arg_ty]:
340    | a=param ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
341    | a=param tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
342param_no_default_star_annotation[arg_ty]:
343    | a=param_star_annotation ',' tc=TYPE_COMMENT? { _PyPegen_add_type_comment_to_arg(p, a, tc) }
344    | a=param_star_annotation tc=TYPE_COMMENT? &')' { _PyPegen_add_type_comment_to_arg(p, a, tc) }
345param_with_default[NameDefaultPair*]:
346    | a=param c=default ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
347    | a=param c=default tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
348param_maybe_default[NameDefaultPair*]:
349    | a=param c=default? ',' tc=TYPE_COMMENT? { _PyPegen_name_default_pair(p, a, c, tc) }
350    | a=param c=default? tc=TYPE_COMMENT? &')' { _PyPegen_name_default_pair(p, a, c, tc) }
351param[arg_ty]: a=NAME b=annotation? { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
352param_star_annotation[arg_ty]: a=NAME b=star_annotation { _PyAST_arg(a->v.Name.id, b, NULL, EXTRA) }
353annotation[expr_ty]: ':' a=expression { a }
354star_annotation[expr_ty]: ':' a=star_expression { a }
355default[expr_ty]: '=' a=expression { a } | invalid_default
356
357# If statement
358# ------------
359
360if_stmt[stmt_ty]:
361    | invalid_if_stmt
362    | 'if' a=named_expression ':' b=block c=elif_stmt {
363        _PyAST_If(a, b, CHECK(asdl_stmt_seq*, _PyPegen_singleton_seq(p, c)), EXTRA) }
364    | 'if' a=named_expression ':' b=block c=[else_block] { _PyAST_If(a, b, c, EXTRA) }
365elif_stmt[stmt_ty]:
366    | invalid_elif_stmt
367    | 'elif' a=named_expression ':' b=block c=elif_stmt {
368        _PyAST_If(a, b, CHECK(asdl_stmt_seq*, _PyPegen_singleton_seq(p, c)), EXTRA) }
369    | 'elif' a=named_expression ':' b=block c=[else_block] { _PyAST_If(a, b, c, EXTRA) }
370else_block[asdl_stmt_seq*]:
371    | invalid_else_stmt
372    | 'else' &&':' b=block { b }
373
374# While statement
375# ---------------
376
377while_stmt[stmt_ty]:
378    | invalid_while_stmt
379    | 'while' a=named_expression ':' b=block c=[else_block] { _PyAST_While(a, b, c, EXTRA) }
380
381# For statement
382# -------------
383
384for_stmt[stmt_ty]:
385    | invalid_for_stmt
386    | 'for' t=star_targets 'in' ~ ex=star_expressions ':' tc=[TYPE_COMMENT] b=block el=[else_block] {
387        _PyAST_For(t, ex, b, el, NEW_TYPE_COMMENT(p, tc), EXTRA) }
388    | 'async' 'for' t=star_targets 'in' ~ ex=star_expressions ':' tc=[TYPE_COMMENT] b=block el=[else_block] {
389        CHECK_VERSION(stmt_ty, 5, "Async for loops are", _PyAST_AsyncFor(t, ex, b, el, NEW_TYPE_COMMENT(p, tc), EXTRA)) }
390    | invalid_for_target
391
392# With statement
393# --------------
394
395with_stmt[stmt_ty]:
396    | invalid_with_stmt_indent
397    | 'with' '(' a[asdl_withitem_seq*]=','.with_item+ ','? ')' ':' tc=[TYPE_COMMENT] b=block {
398       _PyAST_With(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
399    | 'with' a[asdl_withitem_seq*]=','.with_item+ ':' tc=[TYPE_COMMENT] b=block {
400        _PyAST_With(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
401    | 'async' 'with' '(' a[asdl_withitem_seq*]=','.with_item+ ','? ')' ':' b=block {
402       CHECK_VERSION(stmt_ty, 5, "Async with statements are", _PyAST_AsyncWith(a, b, NULL, EXTRA)) }
403    | 'async' 'with' a[asdl_withitem_seq*]=','.with_item+ ':' tc=[TYPE_COMMENT] b=block {
404       CHECK_VERSION(stmt_ty, 5, "Async with statements are", _PyAST_AsyncWith(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA)) }
405    | invalid_with_stmt
406
407with_item[withitem_ty]:
408    | e=expression 'as' t=star_target &(',' | ')' | ':') { _PyAST_withitem(e, t, p->arena) }
409    | invalid_with_item
410    | e=expression { _PyAST_withitem(e, NULL, p->arena) }
411
412# Try statement
413# -------------
414
415try_stmt[stmt_ty]:
416    | invalid_try_stmt
417    | 'try' &&':' b=block f=finally_block { _PyAST_Try(b, NULL, NULL, f, EXTRA) }
418    | 'try' &&':' b=block ex[asdl_excepthandler_seq*]=except_block+ el=[else_block] f=[finally_block] { _PyAST_Try(b, ex, el, f, EXTRA) }
419    | 'try' &&':' b=block ex[asdl_excepthandler_seq*]=except_star_block+ el=[else_block] f=[finally_block] {
420        CHECK_VERSION(stmt_ty, 11, "Exception groups are",
421                      _PyAST_TryStar(b, ex, el, f, EXTRA)) }
422
423
424# Except statement
425# ----------------
426
427except_block[excepthandler_ty]:
428    | invalid_except_stmt_indent
429    | 'except' e=expression t=['as' z=NAME { z }] ':' b=block {
430        _PyAST_ExceptHandler(e, (t) ? ((expr_ty) t)->v.Name.id : NULL, b, EXTRA) }
431    | 'except' ':' b=block { _PyAST_ExceptHandler(NULL, NULL, b, EXTRA) }
432    | invalid_except_stmt
433except_star_block[excepthandler_ty]:
434    | invalid_except_star_stmt_indent
435    | 'except' '*' e=expression t=['as' z=NAME { z }] ':' b=block {
436        _PyAST_ExceptHandler(e, (t) ? ((expr_ty) t)->v.Name.id : NULL, b, EXTRA) }
437    | invalid_except_stmt
438finally_block[asdl_stmt_seq*]:
439    | invalid_finally_stmt
440    | 'finally' &&':' a=block { a }
441
442# Match statement
443# ---------------
444
445match_stmt[stmt_ty]:
446    | "match" subject=subject_expr ':' NEWLINE INDENT cases[asdl_match_case_seq*]=case_block+ DEDENT {
447        CHECK_VERSION(stmt_ty, 10, "Pattern matching is", _PyAST_Match(subject, cases, EXTRA)) }
448    | invalid_match_stmt
449
450subject_expr[expr_ty]:
451    | value=star_named_expression ',' values=star_named_expressions? {
452        _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, value, values)), Load, EXTRA) }
453    | named_expression
454
455case_block[match_case_ty]:
456    | invalid_case_block
457    | "case" pattern=patterns guard=guard? ':' body=block {
458        _PyAST_match_case(pattern, guard, body, p->arena) }
459
460guard[expr_ty]: 'if' guard=named_expression { guard }
461
462patterns[pattern_ty]:
463    | patterns[asdl_pattern_seq*]=open_sequence_pattern {
464        _PyAST_MatchSequence(patterns, EXTRA) }
465    | pattern
466
467pattern[pattern_ty]:
468    | as_pattern
469    | or_pattern
470
471as_pattern[pattern_ty]:
472    | pattern=or_pattern 'as' target=pattern_capture_target {
473        _PyAST_MatchAs(pattern, target->v.Name.id, EXTRA) }
474    | invalid_as_pattern
475
476or_pattern[pattern_ty]:
477    | patterns[asdl_pattern_seq*]='|'.closed_pattern+ {
478        asdl_seq_LEN(patterns) == 1 ? asdl_seq_GET(patterns, 0) : _PyAST_MatchOr(patterns, EXTRA) }
479
480closed_pattern[pattern_ty] (memo):
481    | literal_pattern
482    | capture_pattern
483    | wildcard_pattern
484    | value_pattern
485    | group_pattern
486    | sequence_pattern
487    | mapping_pattern
488    | class_pattern
489
490# Literal patterns are used for equality and identity constraints
491literal_pattern[pattern_ty]:
492    | value=signed_number !('+' | '-') { _PyAST_MatchValue(value, EXTRA) }
493    | value=complex_number { _PyAST_MatchValue(value, EXTRA) }
494    | value=strings { _PyAST_MatchValue(value, EXTRA) }
495    | 'None' { _PyAST_MatchSingleton(Py_None, EXTRA) }
496    | 'True' { _PyAST_MatchSingleton(Py_True, EXTRA) }
497    | 'False' { _PyAST_MatchSingleton(Py_False, EXTRA) }
498
499# Literal expressions are used to restrict permitted mapping pattern keys
500literal_expr[expr_ty]:
501    | signed_number !('+' | '-')
502    | complex_number
503    | strings
504    | 'None' { _PyAST_Constant(Py_None, NULL, EXTRA) }
505    | 'True' { _PyAST_Constant(Py_True, NULL, EXTRA) }
506    | 'False' { _PyAST_Constant(Py_False, NULL, EXTRA) }
507
508complex_number[expr_ty]:
509    | real=signed_real_number '+' imag=imaginary_number {
510        _PyAST_BinOp(real, Add, imag, EXTRA) }
511    | real=signed_real_number '-' imag=imaginary_number  {
512        _PyAST_BinOp(real, Sub, imag, EXTRA) }
513
514signed_number[expr_ty]:
515    | NUMBER
516    | '-' number=NUMBER { _PyAST_UnaryOp(USub, number, EXTRA) }
517
518signed_real_number[expr_ty]:
519    | real_number
520    | '-' real=real_number { _PyAST_UnaryOp(USub, real, EXTRA) }
521
522real_number[expr_ty]:
523    | real=NUMBER { _PyPegen_ensure_real(p, real) }
524
525imaginary_number[expr_ty]:
526    | imag=NUMBER { _PyPegen_ensure_imaginary(p, imag) }
527
528capture_pattern[pattern_ty]:
529    | target=pattern_capture_target { _PyAST_MatchAs(NULL, target->v.Name.id, EXTRA) }
530
531pattern_capture_target[expr_ty]:
532    | !"_" name=NAME !('.' | '(' | '=') {
533        _PyPegen_set_expr_context(p, name, Store) }
534
535wildcard_pattern[pattern_ty]:
536    | "_" { _PyAST_MatchAs(NULL, NULL, EXTRA) }
537
538value_pattern[pattern_ty]:
539    | attr=attr !('.' | '(' | '=') { _PyAST_MatchValue(attr, EXTRA) }
540
541attr[expr_ty]:
542    | value=name_or_attr '.' attr=NAME {
543        _PyAST_Attribute(value, attr->v.Name.id, Load, EXTRA) }
544
545name_or_attr[expr_ty]:
546    | attr
547    | NAME
548
549group_pattern[pattern_ty]:
550    | '(' pattern=pattern ')' { pattern }
551
552sequence_pattern[pattern_ty]:
553    | '[' patterns=maybe_sequence_pattern? ']' { _PyAST_MatchSequence(patterns, EXTRA) }
554    | '(' patterns=open_sequence_pattern? ')' { _PyAST_MatchSequence(patterns, EXTRA) }
555
556open_sequence_pattern[asdl_seq*]:
557    | pattern=maybe_star_pattern ',' patterns=maybe_sequence_pattern? {
558        _PyPegen_seq_insert_in_front(p, pattern, patterns) }
559
560maybe_sequence_pattern[asdl_seq*]:
561    | patterns=','.maybe_star_pattern+ ','? { patterns }
562
563maybe_star_pattern[pattern_ty]:
564    | star_pattern
565    | pattern
566
567star_pattern[pattern_ty] (memo):
568    | '*' target=pattern_capture_target {
569        _PyAST_MatchStar(target->v.Name.id, EXTRA) }
570    | '*' wildcard_pattern {
571        _PyAST_MatchStar(NULL, EXTRA) }
572
573mapping_pattern[pattern_ty]:
574    | '{' '}' {
575        _PyAST_MatchMapping(NULL, NULL, NULL, EXTRA) }
576    | '{' rest=double_star_pattern ','? '}' {
577        _PyAST_MatchMapping(NULL, NULL, rest->v.Name.id, EXTRA) }
578    | '{' items=items_pattern ',' rest=double_star_pattern ','? '}' {
579        _PyAST_MatchMapping(
580            CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, items)),
581            CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, items)),
582            rest->v.Name.id,
583            EXTRA) }
584    | '{' items=items_pattern ','? '}' {
585        _PyAST_MatchMapping(
586            CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, items)),
587            CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, items)),
588            NULL,
589            EXTRA) }
590
591items_pattern[asdl_seq*]:
592    | ','.key_value_pattern+
593
594key_value_pattern[KeyPatternPair*]:
595    | key=(literal_expr | attr) ':' pattern=pattern {
596        _PyPegen_key_pattern_pair(p, key, pattern) }
597
598double_star_pattern[expr_ty]:
599    | '**' target=pattern_capture_target { target }
600
601class_pattern[pattern_ty]:
602    | cls=name_or_attr '(' ')' {
603        _PyAST_MatchClass(cls, NULL, NULL, NULL, EXTRA) }
604    | cls=name_or_attr '(' patterns=positional_patterns ','? ')' {
605        _PyAST_MatchClass(cls, patterns, NULL, NULL, EXTRA) }
606    | cls=name_or_attr '(' keywords=keyword_patterns ','? ')' {
607        _PyAST_MatchClass(
608            cls, NULL,
609            CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p,
610                CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, keywords)))),
611            CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, keywords)),
612            EXTRA) }
613    | cls=name_or_attr '(' patterns=positional_patterns ',' keywords=keyword_patterns ','? ')' {
614        _PyAST_MatchClass(
615            cls,
616            patterns,
617            CHECK(asdl_identifier_seq*, _PyPegen_map_names_to_ids(p,
618                CHECK(asdl_expr_seq*, _PyPegen_get_pattern_keys(p, keywords)))),
619            CHECK(asdl_pattern_seq*, _PyPegen_get_patterns(p, keywords)),
620            EXTRA) }
621    | invalid_class_pattern
622
623positional_patterns[asdl_pattern_seq*]:
624    | args[asdl_pattern_seq*]=','.pattern+ { args }
625
626keyword_patterns[asdl_seq*]:
627    | ','.keyword_pattern+
628
629keyword_pattern[KeyPatternPair*]:
630    | arg=NAME '=' value=pattern { _PyPegen_key_pattern_pair(p, arg, value) }
631
632# Type statement
633# ---------------
634
635type_alias[stmt_ty]:
636    | "type" n=NAME t=[type_params] '=' b=expression {
637        CHECK_VERSION(stmt_ty, 12, "Type statement is",
638        _PyAST_TypeAlias(CHECK(expr_ty, _PyPegen_set_expr_context(p, n, Store)), t, b, EXTRA)) }
639
640# Type parameter declaration
641# --------------------------
642
643type_params[asdl_type_param_seq*]:
644    | invalid_type_params
645    | '[' t=type_param_seq ']' {
646        CHECK_VERSION(asdl_type_param_seq *, 12, "Type parameter lists are", t) }
647
648type_param_seq[asdl_type_param_seq*]: a[asdl_type_param_seq*]=','.type_param+ [','] { a }
649
650type_param[type_param_ty] (memo):
651    | a=NAME b=[type_param_bound] c=[type_param_default] { _PyAST_TypeVar(a->v.Name.id, b, c, EXTRA) }
652    | '*' a=NAME colon=':' e=expression {
653            RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
654                ? "cannot use constraints with TypeVarTuple"
655                : "cannot use bound with TypeVarTuple")
656        }
657    | '*' a=NAME b=[type_param_starred_default] { _PyAST_TypeVarTuple(a->v.Name.id, b, EXTRA) }
658    | '**' a=NAME colon=':' e=expression {
659            RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
660                ? "cannot use constraints with ParamSpec"
661                : "cannot use bound with ParamSpec")
662        }
663    | '**' a=NAME b=[type_param_default] { _PyAST_ParamSpec(a->v.Name.id, b, EXTRA) }
664
665type_param_bound[expr_ty]: ':' e=expression { e }
666type_param_default[expr_ty]: '=' e=expression {
667    CHECK_VERSION(expr_ty, 13, "Type parameter defaults are", e) }
668type_param_starred_default[expr_ty]: '=' e=star_expression {
669    CHECK_VERSION(expr_ty, 13, "Type parameter defaults are", e) }
670
671# EXPRESSIONS
672# -----------
673
674expressions[expr_ty]:
675    | a=expression b=(',' c=expression { c })+ [','] {
676        _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) }
677    | a=expression ',' { _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_singleton_seq(p, a)), Load, EXTRA) }
678    | expression
679
680expression[expr_ty] (memo):
681    | invalid_expression
682    | invalid_legacy_expression
683    | a=disjunction 'if' b=disjunction 'else' c=expression { _PyAST_IfExp(b, a, c, EXTRA) }
684    | disjunction
685    | lambdef
686
687yield_expr[expr_ty]:
688    | 'yield' 'from' a=expression { _PyAST_YieldFrom(a, EXTRA) }
689    | 'yield' a=[star_expressions] { _PyAST_Yield(a, EXTRA) }
690
691star_expressions[expr_ty]:
692    | a=star_expression b=(',' c=star_expression { c })+ [','] {
693        _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) }
694    | a=star_expression ',' { _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_singleton_seq(p, a)), Load, EXTRA) }
695    | star_expression
696
697star_expression[expr_ty] (memo):
698    | '*' a=bitwise_or { _PyAST_Starred(a, Load, EXTRA) }
699    | expression
700
701star_named_expressions[asdl_expr_seq*]: a[asdl_expr_seq*]=','.star_named_expression+ [','] { a }
702
703star_named_expression[expr_ty]:
704    | '*' a=bitwise_or { _PyAST_Starred(a, Load, EXTRA) }
705    | named_expression
706
707assignment_expression[expr_ty]:
708    | a=NAME ':=' ~ b=expression {
709        CHECK_VERSION(expr_ty, 8, "Assignment expressions are",
710        _PyAST_NamedExpr(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), b, EXTRA)) }
711
712named_expression[expr_ty]:
713    | assignment_expression
714    | invalid_named_expression
715    | expression !':='
716
717disjunction[expr_ty] (memo):
718    | a=conjunction b=('or' c=conjunction { c })+ { _PyAST_BoolOp(
719        Or,
720        CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)),
721        EXTRA) }
722    | conjunction
723
724conjunction[expr_ty] (memo):
725    | a=inversion b=('and' c=inversion { c })+ { _PyAST_BoolOp(
726        And,
727        CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)),
728        EXTRA) }
729    | inversion
730
731inversion[expr_ty] (memo):
732    | 'not' a=inversion { _PyAST_UnaryOp(Not, a, EXTRA) }
733    | comparison
734
735# Comparison operators
736# --------------------
737
738comparison[expr_ty]:
739    | a=bitwise_or b=compare_op_bitwise_or_pair+ {
740        _PyAST_Compare(
741            a,
742            CHECK(asdl_int_seq*, _PyPegen_get_cmpops(p, b)),
743            CHECK(asdl_expr_seq*, _PyPegen_get_exprs(p, b)),
744            EXTRA) }
745    | bitwise_or
746
747compare_op_bitwise_or_pair[CmpopExprPair*]:
748    | eq_bitwise_or
749    | noteq_bitwise_or
750    | lte_bitwise_or
751    | lt_bitwise_or
752    | gte_bitwise_or
753    | gt_bitwise_or
754    | notin_bitwise_or
755    | in_bitwise_or
756    | isnot_bitwise_or
757    | is_bitwise_or
758
759eq_bitwise_or[CmpopExprPair*]: '==' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Eq, a) }
760noteq_bitwise_or[CmpopExprPair*]:
761    | (tok='!=' { _PyPegen_check_barry_as_flufl(p, tok) ? NULL : tok}) a=bitwise_or {_PyPegen_cmpop_expr_pair(p, NotEq, a) }
762lte_bitwise_or[CmpopExprPair*]: '<=' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, LtE, a) }
763lt_bitwise_or[CmpopExprPair*]: '<' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Lt, a) }
764gte_bitwise_or[CmpopExprPair*]: '>=' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, GtE, a) }
765gt_bitwise_or[CmpopExprPair*]: '>' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Gt, a) }
766notin_bitwise_or[CmpopExprPair*]: 'not' 'in' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, NotIn, a) }
767in_bitwise_or[CmpopExprPair*]: 'in' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, In, a) }
768isnot_bitwise_or[CmpopExprPair*]: 'is' 'not' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, IsNot, a) }
769is_bitwise_or[CmpopExprPair*]: 'is' a=bitwise_or { _PyPegen_cmpop_expr_pair(p, Is, a) }
770
771# Bitwise operators
772# -----------------
773
774bitwise_or[expr_ty]:
775    | a=bitwise_or '|' b=bitwise_xor { _PyAST_BinOp(a, BitOr, b, EXTRA) }
776    | bitwise_xor
777
778bitwise_xor[expr_ty]:
779    | a=bitwise_xor '^' b=bitwise_and { _PyAST_BinOp(a, BitXor, b, EXTRA) }
780    | bitwise_and
781
782bitwise_and[expr_ty]:
783    | a=bitwise_and '&' b=shift_expr { _PyAST_BinOp(a, BitAnd, b, EXTRA) }
784    | shift_expr
785
786shift_expr[expr_ty]:
787    | a=shift_expr '<<' b=sum { _PyAST_BinOp(a, LShift, b, EXTRA) }
788    | a=shift_expr '>>' b=sum { _PyAST_BinOp(a, RShift, b, EXTRA) }
789    | invalid_arithmetic
790    | sum
791
792# Arithmetic operators
793# --------------------
794
795sum[expr_ty]:
796    | a=sum '+' b=term { _PyAST_BinOp(a, Add, b, EXTRA) }
797    | a=sum '-' b=term { _PyAST_BinOp(a, Sub, b, EXTRA) }
798    | term
799
800term[expr_ty]:
801    | a=term '*' b=factor { _PyAST_BinOp(a, Mult, b, EXTRA) }
802    | a=term '/' b=factor { _PyAST_BinOp(a, Div, b, EXTRA) }
803    | a=term '//' b=factor { _PyAST_BinOp(a, FloorDiv, b, EXTRA) }
804    | a=term '%' b=factor { _PyAST_BinOp(a, Mod, b, EXTRA) }
805    | a=term '@' b=factor { CHECK_VERSION(expr_ty, 5, "The '@' operator is", _PyAST_BinOp(a, MatMult, b, EXTRA)) }
806    | invalid_factor
807    | factor
808
809factor[expr_ty] (memo):
810    | '+' a=factor { _PyAST_UnaryOp(UAdd, a, EXTRA) }
811    | '-' a=factor { _PyAST_UnaryOp(USub, a, EXTRA) }
812    | '~' a=factor { _PyAST_UnaryOp(Invert, a, EXTRA) }
813    | power
814
815power[expr_ty]:
816    | a=await_primary '**' b=factor { _PyAST_BinOp(a, Pow, b, EXTRA) }
817    | await_primary
818
819# Primary elements
820# ----------------
821
822# Primary elements are things like "obj.something.something", "obj[something]", "obj(something)", "obj" ...
823
824await_primary[expr_ty] (memo):
825    | 'await' a=primary { CHECK_VERSION(expr_ty, 5, "Await expressions are", _PyAST_Await(a, EXTRA)) }
826    | primary
827
828primary[expr_ty]:
829    | a=primary '.' b=NAME { _PyAST_Attribute(a, b->v.Name.id, Load, EXTRA) }
830    | a=primary b=genexp { _PyAST_Call(a, CHECK(asdl_expr_seq*, (asdl_expr_seq*)_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }
831    | a=primary '(' b=[arguments] ')' {
832        _PyAST_Call(a,
833                 (b) ? ((expr_ty) b)->v.Call.args : NULL,
834                 (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
835                 EXTRA) }
836    | a=primary '[' b=slices ']' { _PyAST_Subscript(a, b, Load, EXTRA) }
837    | atom
838
839slices[expr_ty]:
840    | a=slice !',' { a }
841    | a[asdl_expr_seq*]=','.(slice | starred_expression)+ [','] { _PyAST_Tuple(a, Load, EXTRA) }
842
843slice[expr_ty]:
844    | a=[expression] ':' b=[expression] c=[':' d=[expression] { d }] { _PyAST_Slice(a, b, c, EXTRA) }
845    | a=named_expression { a }
846
847atom[expr_ty]:
848    | NAME
849    | 'True' { _PyAST_Constant(Py_True, NULL, EXTRA) }
850    | 'False' { _PyAST_Constant(Py_False, NULL, EXTRA) }
851    | 'None' { _PyAST_Constant(Py_None, NULL, EXTRA) }
852    | &(STRING|FSTRING_START) strings
853    | NUMBER
854    | &'(' (tuple | group | genexp)
855    | &'[' (list | listcomp)
856    | &'{' (dict | set | dictcomp | setcomp)
857    | '...' { _PyAST_Constant(Py_Ellipsis, NULL, EXTRA) }
858
859group[expr_ty]:
860    | '(' a=(yield_expr | named_expression) ')' { a }
861    | invalid_group
862
863# Lambda functions
864# ----------------
865
866lambdef[expr_ty]:
867    | 'lambda' a=[lambda_params] ':' b=expression {
868        _PyAST_Lambda((a) ? a : CHECK(arguments_ty, _PyPegen_empty_arguments(p)), b, EXTRA) }
869
870lambda_params[arguments_ty]:
871    | invalid_lambda_parameters
872    | lambda_parameters
873
874# lambda_parameters etc. duplicates parameters but without annotations
875# or type comments, and if there's no comma after a parameter, we expect
876# a colon, not a close parenthesis.  (For more, see parameters above.)
877#
878lambda_parameters[arguments_ty]:
879    | a=lambda_slash_no_default b[asdl_arg_seq*]=lambda_param_no_default* c=lambda_param_with_default* d=[lambda_star_etc] {
880        CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, a, NULL, b, c, d)) }
881    | a=lambda_slash_with_default b=lambda_param_with_default* c=[lambda_star_etc] {
882        CHECK_VERSION(arguments_ty, 8, "Positional-only parameters are", _PyPegen_make_arguments(p, NULL, a, NULL, b, c)) }
883    | a[asdl_arg_seq*]=lambda_param_no_default+ b=lambda_param_with_default* c=[lambda_star_etc] {
884        _PyPegen_make_arguments(p, NULL, NULL, a, b, c) }
885    | a=lambda_param_with_default+ b=[lambda_star_etc] { _PyPegen_make_arguments(p, NULL, NULL, NULL, a, b)}
886    | a=lambda_star_etc { _PyPegen_make_arguments(p, NULL, NULL, NULL, NULL, a) }
887
888lambda_slash_no_default[asdl_arg_seq*]:
889    | a[asdl_arg_seq*]=lambda_param_no_default+ '/' ',' { a }
890    | a[asdl_arg_seq*]=lambda_param_no_default+ '/' &':' { a }
891
892lambda_slash_with_default[SlashWithDefault*]:
893    | a=lambda_param_no_default* b=lambda_param_with_default+ '/' ',' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
894    | a=lambda_param_no_default* b=lambda_param_with_default+ '/' &':' { _PyPegen_slash_with_default(p, (asdl_arg_seq *)a, b) }
895
896lambda_star_etc[StarEtc*]:
897    | invalid_lambda_star_etc
898    | '*' a=lambda_param_no_default b=lambda_param_maybe_default* c=[lambda_kwds] {
899        _PyPegen_star_etc(p, a, b, c) }
900    | '*' ',' b=lambda_param_maybe_default+ c=[lambda_kwds] {
901        _PyPegen_star_etc(p, NULL, b, c) }
902    | a=lambda_kwds { _PyPegen_star_etc(p, NULL, NULL, a) }
903
904lambda_kwds[arg_ty]:
905    | invalid_lambda_kwds
906    | '**' a=lambda_param_no_default { a }
907
908lambda_param_no_default[arg_ty]:
909    | a=lambda_param ',' { a }
910    | a=lambda_param &':' { a }
911lambda_param_with_default[NameDefaultPair*]:
912    | a=lambda_param c=default ',' { _PyPegen_name_default_pair(p, a, c, NULL) }
913    | a=lambda_param c=default &':' { _PyPegen_name_default_pair(p, a, c, NULL) }
914lambda_param_maybe_default[NameDefaultPair*]:
915    | a=lambda_param c=default? ',' { _PyPegen_name_default_pair(p, a, c, NULL) }
916    | a=lambda_param c=default? &':' { _PyPegen_name_default_pair(p, a, c, NULL) }
917lambda_param[arg_ty]: a=NAME { _PyAST_arg(a->v.Name.id, NULL, NULL, EXTRA) }
918
919# LITERALS
920# ========
921
922fstring_middle[expr_ty]:
923    | fstring_replacement_field
924    | t=FSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
925fstring_replacement_field[expr_ty]:
926    | '{' a=annotated_rhs debug_expr='='? conversion=[fstring_conversion] format=[fstring_full_format_spec] rbrace='}' {
927        _PyPegen_formatted_value(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
928    | invalid_replacement_field
929fstring_conversion[ResultTokenWithMetadata*]:
930    | conv_token="!" conv=NAME { _PyPegen_check_fstring_conversion(p, conv_token, conv) }
931fstring_full_format_spec[ResultTokenWithMetadata*]:
932    | colon=':' spec=fstring_format_spec* { _PyPegen_setup_full_format_spec(p, colon, (asdl_expr_seq *) spec, EXTRA) }
933fstring_format_spec[expr_ty]:
934    | t=FSTRING_MIDDLE { _PyPegen_decoded_constant_from_token(p, t) }
935    | fstring_replacement_field
936fstring[expr_ty]:
937    | a=FSTRING_START b=fstring_middle* c=FSTRING_END { _PyPegen_joined_str(p, a, (asdl_expr_seq*)b, c) }
938
939string[expr_ty]: s[Token*]=STRING { _PyPegen_constant_from_string(p, s) }
940strings[expr_ty] (memo): a[asdl_expr_seq*]=(fstring|string)+ { _PyPegen_concatenate_strings(p, a, EXTRA) }
941
942list[expr_ty]:
943    | '[' a=[star_named_expressions] ']' { _PyAST_List(a, Load, EXTRA) }
944
945tuple[expr_ty]:
946    | '(' a=[y=star_named_expression ',' z=[star_named_expressions] { _PyPegen_seq_insert_in_front(p, y, z) } ] ')' {
947        _PyAST_Tuple(a, Load, EXTRA) }
948
949set[expr_ty]: '{' a=star_named_expressions '}' { _PyAST_Set(a, EXTRA) }
950
951# Dicts
952# -----
953
954dict[expr_ty]:
955    | '{' a=[double_starred_kvpairs] '}' {
956        _PyAST_Dict(
957            CHECK(asdl_expr_seq*, _PyPegen_get_keys(p, a)),
958            CHECK(asdl_expr_seq*, _PyPegen_get_values(p, a)),
959            EXTRA) }
960    | '{' invalid_double_starred_kvpairs '}'
961
962double_starred_kvpairs[asdl_seq*]: a=','.double_starred_kvpair+ [','] { a }
963
964double_starred_kvpair[KeyValuePair*]:
965    | '**' a=bitwise_or { _PyPegen_key_value_pair(p, NULL, a) }
966    | kvpair
967
968kvpair[KeyValuePair*]: a=expression ':' b=expression { _PyPegen_key_value_pair(p, a, b) }
969
970# Comprehensions & Generators
971# ---------------------------
972
973for_if_clauses[asdl_comprehension_seq*]:
974    | a[asdl_comprehension_seq*]=for_if_clause+ { a }
975
976for_if_clause[comprehension_ty]:
977    | 'async' 'for' a=star_targets 'in' ~ b=disjunction c[asdl_expr_seq*]=('if' z=disjunction { z })* {
978        CHECK_VERSION(comprehension_ty, 6, "Async comprehensions are", _PyAST_comprehension(a, b, c, 1, p->arena)) }
979    | 'for' a=star_targets 'in' ~ b=disjunction c[asdl_expr_seq*]=('if' z=disjunction { z })* {
980        _PyAST_comprehension(a, b, c, 0, p->arena) }
981    | 'async'? 'for' (bitwise_or (',' bitwise_or)* [',']) !'in' {
982        RAISE_SYNTAX_ERROR("'in' expected after for-loop variables") }
983    | invalid_for_target
984
985listcomp[expr_ty]:
986    | '[' a=named_expression b=for_if_clauses ']' { _PyAST_ListComp(a, b, EXTRA) }
987    | invalid_comprehension
988
989setcomp[expr_ty]:
990    | '{' a=named_expression b=for_if_clauses '}' { _PyAST_SetComp(a, b, EXTRA) }
991    | invalid_comprehension
992
993genexp[expr_ty]:
994    | '(' a=( assignment_expression | expression !':=') b=for_if_clauses ')' { _PyAST_GeneratorExp(a, b, EXTRA) }
995    | invalid_comprehension
996
997dictcomp[expr_ty]:
998    | '{' a=kvpair b=for_if_clauses '}' { _PyAST_DictComp(a->key, a->value, b, EXTRA) }
999    | invalid_dict_comprehension
1000
1001# FUNCTION CALL ARGUMENTS
1002# =======================
1003
1004arguments[expr_ty] (memo):
1005    | a=args [','] &')' { a }
1006    | invalid_arguments
1007
1008args[expr_ty]:
1009    | a[asdl_expr_seq*]=','.(starred_expression | ( assignment_expression | expression !':=') !'=')+ b=[',' k=kwargs {k}] {
1010        _PyPegen_collect_call_seqs(p, a, b, EXTRA) }
1011    | a=kwargs { _PyAST_Call(_PyPegen_dummy_name(p),
1012                          CHECK_NULL_ALLOWED(asdl_expr_seq*, _PyPegen_seq_extract_starred_exprs(p, a)),
1013                          CHECK_NULL_ALLOWED(asdl_keyword_seq*, _PyPegen_seq_delete_starred_exprs(p, a)),
1014                          EXTRA) }
1015
1016kwargs[asdl_seq*]:
1017    | a=','.kwarg_or_starred+ ',' b=','.kwarg_or_double_starred+ { _PyPegen_join_sequences(p, a, b) }
1018    | ','.kwarg_or_starred+
1019    | ','.kwarg_or_double_starred+
1020
1021starred_expression[expr_ty]:
1022    | invalid_starred_expression
1023    | '*' a=expression { _PyAST_Starred(a, Load, EXTRA) }
1024    | '*' { RAISE_SYNTAX_ERROR("Invalid star expression") }
1025
1026kwarg_or_starred[KeywordOrStarred*]:
1027    | invalid_kwarg
1028    | a=NAME '=' b=expression {
1029        _PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(a->v.Name.id, b, EXTRA)), 1) }
1030    | a=starred_expression { _PyPegen_keyword_or_starred(p, a, 0) }
1031
1032kwarg_or_double_starred[KeywordOrStarred*]:
1033    | invalid_kwarg
1034    | a=NAME '=' b=expression {
1035        _PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(a->v.Name.id, b, EXTRA)), 1) }
1036    | '**' a=expression { _PyPegen_keyword_or_starred(p, CHECK(keyword_ty, _PyAST_keyword(NULL, a, EXTRA)), 1) }
1037
1038# ASSIGNMENT TARGETS
1039# ==================
1040
1041# Generic targets
1042# ---------------
1043
1044# NOTE: star_targets may contain *bitwise_or, targets may not.
1045star_targets[expr_ty]:
1046    | a=star_target !',' { a }
1047    | a=star_target b=(',' c=star_target { c })* [','] {
1048        _PyAST_Tuple(CHECK(asdl_expr_seq*, _PyPegen_seq_insert_in_front(p, a, b)), Store, EXTRA) }
1049
1050star_targets_list_seq[asdl_expr_seq*]: a[asdl_expr_seq*]=','.star_target+ [','] { a }
1051
1052star_targets_tuple_seq[asdl_expr_seq*]:
1053    | a=star_target b=(',' c=star_target { c })+ [','] { (asdl_expr_seq*) _PyPegen_seq_insert_in_front(p, a, b) }
1054    | a=star_target ',' { (asdl_expr_seq*) _PyPegen_singleton_seq(p, a) }
1055
1056star_target[expr_ty] (memo):
1057    | '*' a=(!'*' star_target) {
1058        _PyAST_Starred(CHECK(expr_ty, _PyPegen_set_expr_context(p, a, Store)), Store, EXTRA) }
1059    | target_with_star_atom
1060
1061target_with_star_atom[expr_ty] (memo):
1062    | a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Store, EXTRA) }
1063    | a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Store, EXTRA) }
1064    | star_atom
1065
1066star_atom[expr_ty]:
1067    | a=NAME { _PyPegen_set_expr_context(p, a, Store) }
1068    | '(' a=target_with_star_atom ')' { _PyPegen_set_expr_context(p, a, Store) }
1069    | '(' a=[star_targets_tuple_seq] ')' { _PyAST_Tuple(a, Store, EXTRA) }
1070    | '[' a=[star_targets_list_seq] ']' { _PyAST_List(a, Store, EXTRA) }
1071
1072single_target[expr_ty]:
1073    | single_subscript_attribute_target
1074    | a=NAME { _PyPegen_set_expr_context(p, a, Store) }
1075    | '(' a=single_target ')' { a }
1076
1077single_subscript_attribute_target[expr_ty]:
1078    | a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Store, EXTRA) }
1079    | a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Store, EXTRA) }
1080
1081t_primary[expr_ty]:
1082    | a=t_primary '.' b=NAME &t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Load, EXTRA) }
1083    | a=t_primary '[' b=slices ']' &t_lookahead { _PyAST_Subscript(a, b, Load, EXTRA) }
1084    | a=t_primary b=genexp &t_lookahead {
1085        _PyAST_Call(a, CHECK(asdl_expr_seq*, (asdl_expr_seq*)_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }
1086    | a=t_primary '(' b=[arguments] ')' &t_lookahead {
1087        _PyAST_Call(a,
1088                 (b) ? ((expr_ty) b)->v.Call.args : NULL,
1089                 (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
1090                 EXTRA) }
1091    | a=atom &t_lookahead { a }
1092
1093t_lookahead: '(' | '[' | '.'
1094
1095# Targets for del statements
1096# --------------------------
1097
1098del_targets[asdl_expr_seq*]: a[asdl_expr_seq*]=','.del_target+ [','] { a }
1099
1100del_target[expr_ty] (memo):
1101    | a=t_primary '.' b=NAME !t_lookahead { _PyAST_Attribute(a, b->v.Name.id, Del, EXTRA) }
1102    | a=t_primary '[' b=slices ']' !t_lookahead { _PyAST_Subscript(a, b, Del, EXTRA) }
1103    | del_t_atom
1104
1105del_t_atom[expr_ty]:
1106    | a=NAME { _PyPegen_set_expr_context(p, a, Del) }
1107    | '(' a=del_target ')' { _PyPegen_set_expr_context(p, a, Del) }
1108    | '(' a=[del_targets] ')' { _PyAST_Tuple(a, Del, EXTRA) }
1109    | '[' a=[del_targets] ']' { _PyAST_List(a, Del, EXTRA) }
1110
1111# TYPING ELEMENTS
1112# ---------------
1113
1114# type_expressions allow */** but ignore them
1115type_expressions[asdl_expr_seq*]:
1116    | a=','.expression+ ',' '*' b=expression ',' '**' c=expression {
1117        (asdl_expr_seq*)_PyPegen_seq_append_to_end(
1118            p,
1119            CHECK(asdl_seq*, _PyPegen_seq_append_to_end(p, a, b)),
1120            c) }
1121    | a=','.expression+ ',' '*' b=expression { (asdl_expr_seq*)_PyPegen_seq_append_to_end(p, a, b) }
1122    | a=','.expression+ ',' '**' b=expression { (asdl_expr_seq*)_PyPegen_seq_append_to_end(p, a, b) }
1123    | '*' a=expression ',' '**' b=expression {
1124        (asdl_expr_seq*)_PyPegen_seq_append_to_end(
1125            p,
1126            CHECK(asdl_seq*, _PyPegen_singleton_seq(p, a)),
1127            b) }
1128    | '*' a=expression { (asdl_expr_seq*)_PyPegen_singleton_seq(p, a) }
1129    | '**' a=expression { (asdl_expr_seq*)_PyPegen_singleton_seq(p, a) }
1130    | a[asdl_expr_seq*]=','.expression+ {a}
1131
1132func_type_comment[Token*]:
1133    | NEWLINE t=TYPE_COMMENT &(NEWLINE INDENT) { t }  # Must be followed by indented block
1134    | invalid_double_type_comments
1135    | TYPE_COMMENT
1136
1137# ========================= END OF THE GRAMMAR ===========================
1138
1139
1140
1141# ========================= START OF INVALID RULES =======================
1142
1143# From here on, there are rules for invalid syntax with specialised error messages
1144invalid_arguments:
1145    | ((','.(starred_expression | ( assignment_expression | expression !':=') !'=')+ ',' kwargs) | kwargs) a=',' ','.(starred_expression !'=')+ {
1146        RAISE_SYNTAX_ERROR_STARTING_FROM(a, "iterable argument unpacking follows keyword argument unpacking") }
1147    | a=expression b=for_if_clauses ',' [args | expression for_if_clauses] {
1148        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
1149    | a=NAME b='=' expression for_if_clauses {
1150        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
1151    | (args ',')? a=NAME b='=' &(',' | ')') {
1152        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected argument value expression")}
1153    | a=args b=for_if_clauses { _PyPegen_nonparen_genexp_in_call(p, a, b) }
1154    | args ',' a=expression b=for_if_clauses {
1155        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, _PyPegen_get_last_comprehension_item(PyPegen_last_item(b, comprehension_ty)), "Generator expression must be parenthesized") }
1156    | a=args ',' args { _PyPegen_arguments_parsing_error(p, a) }
1157invalid_kwarg:
1158    | a[Token*]=('True'|'False'|'None') b='=' {
1159        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to %s", PyBytes_AS_STRING(a->bytes)) }
1160    | a=NAME b='=' expression for_if_clauses {
1161        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?")}
1162    | !(NAME '=') a=expression b='=' {
1163        RAISE_SYNTAX_ERROR_KNOWN_RANGE(
1164            a, b, "expression cannot contain assignment, perhaps you meant \"==\"?") }
1165    | a='**' expression '=' b=expression {
1166        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to keyword argument unpacking") }
1167
1168# IMPORTANT: Note that the "_without_invalid" suffix causes the rule to not call invalid rules under it
1169expression_without_invalid[expr_ty]:
1170    | a=disjunction 'if' b=disjunction 'else' c=expression { _PyAST_IfExp(b, a, c, EXTRA) }
1171    | disjunction
1172    | lambdef
1173invalid_legacy_expression:
1174    | a=NAME !'(' b=star_expressions {
1175        _PyPegen_check_legacy_stmt(p, a) ? RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b,
1176            "Missing parentheses in call to '%U'. Did you mean %U(...)?", a->v.Name.id, a->v.Name.id) : NULL}
1177
1178invalid_expression:
1179    # !(NAME STRING) is not matched so we don't show this error with some invalid string prefixes like: kf"dsfsdf"
1180    # Soft keywords need to also be ignored because they can be parsed as NAME NAME
1181   | !(NAME STRING | SOFT_KEYWORD) a=disjunction b=expression_without_invalid {
1182        _PyPegen_check_legacy_stmt(p, a) ? NULL : p->tokens[p->mark-1]->level == 0 ? NULL :
1183        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Perhaps you forgot a comma?") }
1184   | a=disjunction 'if' b=disjunction !('else'|':') { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "expected 'else' after 'if' expression") }
1185   | a='lambda' [lambda_params] b=':' &FSTRING_MIDDLE  {
1186        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "f-string: lambda expressions are not allowed without parentheses") }
1187
1188invalid_named_expression(memo):
1189    | a=expression ':=' expression {
1190        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
1191            a, "cannot use assignment expressions with %s", _PyPegen_get_expr_name(a)) }
1192    | a=NAME '=' b=bitwise_or !('='|':=') {
1193        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "invalid syntax. Maybe you meant '==' or ':=' instead of '='?") }
1194    | !(list|tuple|genexp|'True'|'None'|'False') a=bitwise_or b='=' bitwise_or !('='|':=') {
1195        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot assign to %s here. Maybe you meant '==' instead of '='?",
1196                                          _PyPegen_get_expr_name(a)) }
1197
1198invalid_assignment:
1199    | a=invalid_ann_assign_target ':' expression {
1200        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
1201            a,
1202            "only single target (not %s) can be annotated",
1203            _PyPegen_get_expr_name(a)
1204        )}
1205    | a=star_named_expression ',' star_named_expressions* ':' expression {
1206        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "only single target (not tuple) can be annotated") }
1207    | a=expression ':' expression {
1208        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "illegal target for annotation") }
1209    | (star_targets '=')* a=star_expressions '=' {
1210        RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) }
1211    | (star_targets '=')* a=yield_expr '=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "assignment to yield expression not possible") }
1212    | a=star_expressions augassign annotated_rhs {
1213        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
1214            a,
1215            "'%s' is an illegal expression for augmented assignment",
1216            _PyPegen_get_expr_name(a)
1217        )}
1218invalid_ann_assign_target[expr_ty]:
1219    | list
1220    | tuple
1221    | '(' a=invalid_ann_assign_target ')' { a }
1222invalid_del_stmt:
1223    | 'del' a=star_expressions {
1224        RAISE_SYNTAX_ERROR_INVALID_TARGET(DEL_TARGETS, a) }
1225invalid_block:
1226    | NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block") }
1227invalid_comprehension:
1228    | ('[' | '(' | '{') a=starred_expression for_if_clauses {
1229        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "iterable unpacking cannot be used in comprehension") }
1230    | ('[' | '{') a=star_named_expression ',' b=star_named_expressions for_if_clauses {
1231        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, PyPegen_last_item(b, expr_ty),
1232        "did you forget parentheses around the comprehension target?") }
1233    | ('[' | '{') a=star_named_expression b=',' for_if_clauses {
1234        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "did you forget parentheses around the comprehension target?") }
1235invalid_dict_comprehension:
1236    | '{' a='**' bitwise_or for_if_clauses '}' {
1237        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "dict unpacking cannot be used in dict comprehension") }
1238invalid_parameters:
1239    | a="/" ',' {
1240        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "at least one argument must precede /") }
1241    | (slash_no_default | slash_with_default) param_maybe_default* a='/' {
1242        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
1243    | slash_no_default? param_no_default* invalid_parameters_helper a=param_no_default {
1244        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
1245    | param_no_default* a='(' param_no_default+ ','? b=')' {
1246        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Function parameters cannot be parenthesized") }
1247    | (slash_no_default | slash_with_default)? param_maybe_default* '*' (',' | param_no_default) param_maybe_default* a='/' {
1248        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ must be ahead of *") }
1249    | param_maybe_default+ '/' a='*' {
1250        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected comma between / and *") }
1251invalid_default:
1252    | a='=' &(')'|',') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected default value expression") }
1253invalid_star_etc:
1254    | a='*' (')' | ',' (')' | '**')) { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "named arguments must follow bare *") }
1255    | '*' ',' TYPE_COMMENT { RAISE_SYNTAX_ERROR("bare * has associated type comment") }
1256    | '*' param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-positional argument cannot have default value") }
1257    | '*' (param_no_default | ',') param_maybe_default* a='*' (param_no_default | ',') {
1258        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "* argument may appear only once") }
1259invalid_kwds:
1260    | '**' param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-keyword argument cannot have default value") }
1261    | '**' param ',' a=param { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
1262    | '**' param ',' a[Token*]=('*'|'**'|'/') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
1263invalid_parameters_helper: # This is only there to avoid type errors
1264    | a=slash_with_default { _PyPegen_singleton_seq(p, a) }
1265    | param_with_default+
1266invalid_lambda_parameters:
1267    | a="/" ',' {
1268        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "at least one argument must precede /") }
1269    | (lambda_slash_no_default | lambda_slash_with_default) lambda_param_maybe_default* a='/' {
1270        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ may appear only once") }
1271    | lambda_slash_no_default? lambda_param_no_default* invalid_lambda_parameters_helper a=lambda_param_no_default {
1272        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "parameter without a default follows parameter with a default") }
1273    | lambda_param_no_default* a='(' ','.lambda_param+ ','? b=')' {
1274        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "Lambda expression parameters cannot be parenthesized") }
1275    | (lambda_slash_no_default | lambda_slash_with_default)? lambda_param_maybe_default* '*' (',' | lambda_param_no_default) lambda_param_maybe_default* a='/' {
1276        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "/ must be ahead of *") }
1277    | lambda_param_maybe_default+ '/' a='*' {
1278        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expected comma between / and *") }
1279invalid_lambda_parameters_helper:
1280    | a=lambda_slash_with_default { _PyPegen_singleton_seq(p, a) }
1281    | lambda_param_with_default+
1282invalid_lambda_star_etc:
1283    | '*' (':' | ',' (':' | '**')) { RAISE_SYNTAX_ERROR("named arguments must follow bare *") }
1284    | '*' lambda_param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-positional argument cannot have default value") }
1285    | '*' (lambda_param_no_default | ',') lambda_param_maybe_default* a='*' (lambda_param_no_default | ',') {
1286        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "* argument may appear only once") }
1287invalid_lambda_kwds:
1288    | '**' lambda_param a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "var-keyword argument cannot have default value") }
1289    | '**' lambda_param ',' a=lambda_param { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
1290    | '**' lambda_param ',' a[Token*]=('*'|'**'|'/') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "arguments cannot follow var-keyword argument") }
1291invalid_double_type_comments:
1292    | TYPE_COMMENT NEWLINE TYPE_COMMENT NEWLINE INDENT {
1293        RAISE_SYNTAX_ERROR("Cannot have two type comments on def") }
1294invalid_with_item:
1295    | expression 'as' a=expression &(',' | ')' | ':') {
1296        RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) }
1297
1298invalid_for_target:
1299    | 'async'? 'for' a=star_expressions {
1300        RAISE_SYNTAX_ERROR_INVALID_TARGET(FOR_TARGETS, a) }
1301
1302invalid_group:
1303    | '(' a=starred_expression ')' {
1304        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use starred expression here") }
1305    | '(' a='**' expression ')' {
1306        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use double starred expression here") }
1307invalid_import:
1308    | a='import' ','.dotted_name+ 'from' dotted_name {
1309        RAISE_SYNTAX_ERROR_STARTING_FROM(a, "Did you mean to use 'from ... import ...' instead?") }
1310    | 'import' token=NEWLINE {
1311        RAISE_SYNTAX_ERROR_STARTING_FROM(token, "Expected one or more names after 'import'") }
1312
1313invalid_import_from_targets:
1314    | import_from_as_names ',' NEWLINE {
1315        RAISE_SYNTAX_ERROR("trailing comma not allowed without surrounding parentheses") }
1316    | token=NEWLINE {
1317        RAISE_SYNTAX_ERROR_STARTING_FROM(token, "Expected one or more names after 'import'") }
1318
1319invalid_with_stmt:
1320    | ['async'] 'with' ','.(expression ['as' star_target])+ NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1321    | ['async'] 'with' '(' ','.(expressions ['as' star_target])+ ','? ')' NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1322invalid_with_stmt_indent:
1323    | ['async'] a='with' ','.(expression ['as' star_target])+ ':' NEWLINE !INDENT {
1324        RAISE_INDENTATION_ERROR("expected an indented block after 'with' statement on line %d", a->lineno) }
1325    | ['async'] a='with' '(' ','.(expressions ['as' star_target])+ ','? ')' ':' NEWLINE !INDENT {
1326        RAISE_INDENTATION_ERROR("expected an indented block after 'with' statement on line %d", a->lineno) }
1327
1328invalid_try_stmt:
1329    | a='try' ':' NEWLINE !INDENT {
1330        RAISE_INDENTATION_ERROR("expected an indented block after 'try' statement on line %d", a->lineno) }
1331    | 'try' ':' block !('except' | 'finally') { RAISE_SYNTAX_ERROR("expected 'except' or 'finally' block") }
1332    | 'try' ':' block* except_block+ a='except' b='*' expression ['as' NAME] ':' {
1333        RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot have both 'except' and 'except*' on the same 'try'") }
1334    | 'try' ':' block* except_star_block+ a='except' [expression ['as' NAME]] ':' {
1335        RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot have both 'except' and 'except*' on the same 'try'") }
1336invalid_except_stmt:
1337    | 'except' '*'? a=expression ',' expressions ['as' NAME ] ':' {
1338        RAISE_SYNTAX_ERROR_STARTING_FROM(a, "multiple exception types must be parenthesized") }
1339    | a='except' '*'? expression ['as' NAME ] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1340    | a='except' NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1341    | a='except' '*' (NEWLINE | ':') { RAISE_SYNTAX_ERROR("expected one or more exception types") }
1342invalid_finally_stmt:
1343    | a='finally' ':' NEWLINE !INDENT {
1344        RAISE_INDENTATION_ERROR("expected an indented block after 'finally' statement on line %d", a->lineno) }
1345invalid_except_stmt_indent:
1346    | a='except' expression ['as' NAME ] ':' NEWLINE !INDENT {
1347        RAISE_INDENTATION_ERROR("expected an indented block after 'except' statement on line %d", a->lineno) }
1348    | a='except' ':' NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block after 'except' statement on line %d", a->lineno) }
1349invalid_except_star_stmt_indent:
1350    | a='except' '*' expression ['as' NAME ] ':' NEWLINE !INDENT {
1351        RAISE_INDENTATION_ERROR("expected an indented block after 'except*' statement on line %d", a->lineno) }
1352invalid_match_stmt:
1353    | "match" subject_expr NEWLINE { CHECK_VERSION(void*, 10, "Pattern matching is", RAISE_SYNTAX_ERROR("expected ':'") ) }
1354    | a="match" subject=subject_expr ':' NEWLINE !INDENT {
1355        RAISE_INDENTATION_ERROR("expected an indented block after 'match' statement on line %d", a->lineno) }
1356invalid_case_block:
1357    | "case" patterns guard? NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1358    | a="case" patterns guard? ':' NEWLINE !INDENT {
1359        RAISE_INDENTATION_ERROR("expected an indented block after 'case' statement on line %d", a->lineno) }
1360invalid_as_pattern:
1361    | or_pattern 'as' a="_" { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot use '_' as a target") }
1362    | or_pattern 'as' !NAME a=expression { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "invalid pattern target") }
1363invalid_class_pattern:
1364    | name_or_attr '(' a=invalid_class_argument_pattern  { RAISE_SYNTAX_ERROR_KNOWN_RANGE(
1365        PyPegen_first_item(a, pattern_ty),
1366        PyPegen_last_item(a, pattern_ty),
1367        "positional patterns follow keyword patterns") }
1368invalid_class_argument_pattern[asdl_pattern_seq*]:
1369    | [positional_patterns ','] keyword_patterns ',' a=positional_patterns { a }
1370invalid_if_stmt:
1371    | 'if' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1372    | a='if' a=named_expression ':' NEWLINE !INDENT {
1373        RAISE_INDENTATION_ERROR("expected an indented block after 'if' statement on line %d", a->lineno) }
1374invalid_elif_stmt:
1375    | 'elif' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1376    | a='elif' named_expression ':' NEWLINE !INDENT {
1377        RAISE_INDENTATION_ERROR("expected an indented block after 'elif' statement on line %d", a->lineno) }
1378invalid_else_stmt:
1379    | a='else' ':' NEWLINE !INDENT {
1380        RAISE_INDENTATION_ERROR("expected an indented block after 'else' statement on line %d", a->lineno) }
1381invalid_while_stmt:
1382    | 'while' named_expression NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1383    | a='while' named_expression ':' NEWLINE !INDENT {
1384        RAISE_INDENTATION_ERROR("expected an indented block after 'while' statement on line %d", a->lineno) }
1385invalid_for_stmt:
1386    | ['async'] 'for' star_targets 'in' star_expressions NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1387    | ['async'] a='for' star_targets 'in' star_expressions ':' NEWLINE !INDENT {
1388        RAISE_INDENTATION_ERROR("expected an indented block after 'for' statement on line %d", a->lineno) }
1389invalid_def_raw:
1390    | ['async'] a='def' NAME [type_params] '(' [params] ')' ['->' expression] ':' NEWLINE !INDENT {
1391        RAISE_INDENTATION_ERROR("expected an indented block after function definition on line %d", a->lineno) }
1392    | ['async'] 'def' NAME [type_params] &&'(' [params] ')' ['->' expression] &&':' [func_type_comment] block
1393invalid_class_def_raw:
1394    | 'class' NAME [type_params] ['(' [arguments] ')'] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
1395    | a='class' NAME [type_params] ['(' [arguments] ')'] ':' NEWLINE !INDENT {
1396        RAISE_INDENTATION_ERROR("expected an indented block after class definition on line %d", a->lineno) }
1397
1398invalid_double_starred_kvpairs:
1399    | ','.double_starred_kvpair+ ',' invalid_kvpair
1400    | expression ':' a='*' bitwise_or { RAISE_SYNTAX_ERROR_STARTING_FROM(a, "cannot use a starred expression in a dictionary value") }
1401    | expression a=':' &('}'|',') { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expression expected after dictionary key and ':'") }
1402invalid_kvpair:
1403    | a=expression !(':') {
1404        RAISE_ERROR_KNOWN_LOCATION(p, PyExc_SyntaxError, a->lineno, a->end_col_offset - 1, a->end_lineno, -1, "':' expected after dictionary key") }
1405    | expression ':' a='*' bitwise_or { RAISE_SYNTAX_ERROR_STARTING_FROM(a, "cannot use a starred expression in a dictionary value") }
1406    | expression a=':' &('}'|',') {RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "expression expected after dictionary key and ':'") }
1407invalid_starred_expression:
1408    | a='*' expression '=' b=expression { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to iterable argument unpacking") }
1409
1410invalid_replacement_field:
1411    | '{' a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '='") }
1412    | '{' a='!' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '!'") }
1413    | '{' a=':' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before ':'") }
1414    | '{' a='}' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "f-string: valid expression required before '}'") }
1415    | '{' !annotated_rhs { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting a valid expression after '{'")}
1416    | '{' annotated_rhs !('=' | '!' | ':' | '}') {
1417        PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '=', or '!', or ':', or '}'") }
1418    | '{' annotated_rhs '=' !('!' | ':' | '}') {
1419        PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '!', or ':', or '}'") }
1420    | '{' annotated_rhs '='? invalid_conversion_character
1421    | '{' annotated_rhs '='? ['!' NAME] !(':' | '}') {
1422        PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting ':' or '}'") }
1423    | '{' annotated_rhs '='? ['!' NAME] ':' fstring_format_spec* !'}' {
1424        PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}', or format specs") }
1425    | '{' annotated_rhs '='? ['!' NAME] !'}' {
1426        PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}'") }
1427
1428invalid_conversion_character:
1429    | '!' &(':' | '}') { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: missing conversion character") }
1430    | '!' !NAME { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: invalid conversion character") }
1431
1432invalid_arithmetic:
1433    | sum ('+'|'-'|'*'|'/'|'%'|'//'|'@') a='not' b=inversion { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "'not' after an operator must be parenthesized") }
1434invalid_factor:
1435    | ('+' | '-' | '~') a='not' b=factor { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "'not' after an operator must be parenthesized") }
1436
1437invalid_type_params:
1438    | '[' token=']' {
1439        RAISE_SYNTAX_ERROR_STARTING_FROM(
1440            token,
1441            "Type parameter list cannot be empty")}
1442