10. Full Grammar specification
******************************

This is the full Python grammar, derived directly from the grammar
used to generate the CPython parser (see Grammar/python.gram). The
version here omits details related to code generation and error
recovery.

The notation used here is the same as in the preceding docs, and is
described in the notation section, except for an extra complication:

* "~" ("cut"): commit to the current alternative; fail the rule if the
  alternative fails to parse

  Python mainly uses cuts for optimizations or improved error
  messages. They often appear to be useless in the listing below.

  Cuts currently don't appear inside parentheses, brackets, lookaheads
  and similar. Their behavior in these contexts is deliberately left
  unspecified.

   # 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);
       }

       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.
   # &&e
   #   Eager parse e. The parser will not backtrack and will immediately
   #   fail with SyntaxError if e cannot be parsed.
   #

   # 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) }

   # GENERAL STATEMENTS
   # ==================

   statements[asdl_stmt_seq*]: a=statement+ { (asdl_stmt_seq*)_PyPegen_seq_flatten(p, a) }

   statement[asdl_stmt_seq*]:
       | a=compound_stmt { _PyPegen_register_stmts(p ,
                              (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a)
                           ) }
       | a[asdl_stmt_seq*]=simple_stmts { a }

   single_compound_stmt[asdl_stmt_seq*]:
       | a=compound_stmt {
           _PyPegen_register_stmts(p, (asdl_stmt_seq*)_PyPegen_singleton_seq(p, a)) }

   statement_newline[asdl_stmt_seq*]:
       | a=single_compound_stmt NEWLINE { 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' pass_stmt
       | &'del' del_stmt
       | &'yield' yield_stmt
       | &'assert' assert_stmt
       | &'break' break_stmt
       | &'continue' continue_stmt
       | &'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=annotated_rhs !'=' tc=[TYPE_COMMENT] {
            _PyAST_Assign(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) }
       | a=single_target b=augassign ~ c=annotated_rhs {
            _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) }

   pass_stmt[stmt_ty]:
       | 'pass' { _PyAST_Pass(EXTRA) }

   break_stmt[stmt_ty]:
       | 'break' { _PyAST_Break(EXTRA) }

   continue_stmt[stmt_ty]:
       | 'continue' { _PyAST_Continue(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 {
           _PyPegen_checked_future_import(p, 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]:
       | invalid_import_from_as_name
       | 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]:
       | invalid_dotted_as_name
       | 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,
                        (b) ? ((expr_ty) b)->v.Call.args : NULL,
                        (b) ? ((expr_ty) b)->v.Call.keywords : NULL,
                        c, NULL, t, 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,
                           (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
                           b, NULL, a, NEW_TYPE_COMMENT(p, tc), t, 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,
                               (params) ? params : CHECK(arguments_ty, _PyPegen_empty_arguments(p)),
                               b, NULL, a, NEW_TYPE_COMMENT(p, tc), t, 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+ ','? ')' ':' tc=[TYPE_COMMENT] b=block {
          _PyAST_With(a, b, NEW_TYPE_COMMENT(p, tc), 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 ':' b=block {
           _PyAST_ExceptHandler(e, NULL, b, EXTRA) }
       | 'except' e=expression 'as' t=NAME ':' b=block {
           _PyAST_ExceptHandler(e, ((expr_ty) t)->v.Name.id, b, EXTRA) }
       | 'except' e=expressions ':' b=block {
           CHECK_VERSION(
               excepthandler_ty,
               14,
               "except expressions without parentheses are",
               _PyAST_ExceptHandler(e, 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 ':' b=block {
           _PyAST_ExceptHandler(e, NULL, b, EXTRA) }
       | 'except' '*' e=expression 'as' t=NAME ':' b=block {
           _PyAST_ExceptHandler(e, ((expr_ty) t)->v.Name.id, b, EXTRA) }
       | 'except' '*' e=expressions ':' b=block {
           CHECK_VERSION(
               excepthandler_ty,
               14,
               "except expressions without parentheses are",
               _PyAST_ExceptHandler(e,  NULL, b, EXTRA)) }
       | invalid_except_star_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
       | &(STRING|FSTRING_START|TSTRING_START) 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*]:
       | invalid_type_params
       | '[' 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] c=[type_param_default] { _PyAST_TypeVar(a->v.Name.id, b, c, EXTRA) }
       | invalid_type_param
       | '*' a=NAME b=[type_param_starred_default] { _PyAST_TypeVarTuple(a->v.Name.id, b, EXTRA) }
       | '**' a=NAME b=[type_param_default] { _PyAST_ParamSpec(a->v.Name.id, b, EXTRA) }

   type_param_bound[expr_ty]: ':' e=expression { e }
   type_param_default[expr_ty]: '=' e=expression {
       CHECK_VERSION(expr_ty, 13, "Type parameter defaults are", e) }
   type_param_starred_default[expr_ty]: '=' e=star_expression {
       CHECK_VERSION(expr_ty, 13, "Type parameter defaults are", 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) }
       | invalid_arithmetic
       | 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)) }
       | invalid_factor
       | 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|TSTRING_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=annotated_rhs debug_expr='='? conversion=[fstring_conversion] format=[fstring_full_format_spec] rbrace='}' {
           _PyPegen_formatted_value(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
       | invalid_fstring_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_decoded_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) }

   tstring_format_spec_replacement_field[expr_ty]:
       | '{' a=annotated_rhs debug_expr='='? conversion=[fstring_conversion] format=[tstring_full_format_spec] rbrace='}' {
           _PyPegen_formatted_value(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
       | invalid_tstring_replacement_field
   tstring_format_spec[expr_ty]:
       | t=TSTRING_MIDDLE { _PyPegen_decoded_constant_from_token(p, t) }
       | tstring_format_spec_replacement_field
   tstring_full_format_spec[ResultTokenWithMetadata*]:
       | colon=':' spec=tstring_format_spec* { _PyPegen_setup_full_format_spec(p, colon, (asdl_expr_seq *) spec, EXTRA) }
   tstring_replacement_field[expr_ty]:
       | '{' a=annotated_rhs debug_expr='='? conversion=[fstring_conversion] format=[tstring_full_format_spec] rbrace='}' {
           _PyPegen_interpolation(p, a, debug_expr, conversion, format, rbrace, EXTRA) }
       | invalid_tstring_replacement_field
   tstring_middle[expr_ty]:
       | tstring_replacement_field
       | t=TSTRING_MIDDLE { _PyPegen_constant_from_token(p, t) }
   tstring[expr_ty] (memo):
       | a=TSTRING_START b=tstring_middle* c=TSTRING_END {
           CHECK_VERSION(
               expr_ty,
               14,
               "t-strings are",
               _PyPegen_template_str(p, a, (asdl_expr_seq*)b, c)) }

   string[expr_ty]: s[Token*]=STRING { _PyPegen_constant_from_string(p, s) }
   strings[expr_ty] (memo):
       | invalid_string_tstring_concat
       | a[asdl_expr_seq*]=(fstring|string)+ { _PyPegen_concatenate_strings(p, a, EXTRA) }
       | a[asdl_expr_seq*]=tstring+ { _PyPegen_concatenate_tstrings(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_if_clause
       | 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_unpacking
       | '*' a=expression { _PyAST_Starred(a, Load, EXTRA) }
       | invalid_starred_expression

   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:
       | ((','.(starred_expression | ( assignment_expression | expression !':=') !'=')+ ',' kwargs) | kwargs) a=',' ','.(starred_expression !'=')+ {
           RAISE_SYNTAX_ERROR_STARTING_FROM(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_type_param:
       | '*' 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 colon=':' e=expression {
               RAISE_SYNTAX_ERROR_STARTING_FROM(colon, e->kind == Tuple_kind
                   ? "cannot use constraints with ParamSpec"
                   : "cannot use bound with ParamSpec")
           }

   invalid_expression:
      |  STRING a=(!STRING expression_without_invalid)+ STRING {
           RAISE_SYNTAX_ERROR_KNOWN_RANGE( PyPegen_first_item(a, expr_ty), PyPegen_last_item(a, expr_ty),
           "invalid syntax. Is this intended to be part of the string?") }
       # !(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=disjunction 'if' b=disjunction 'else' !expression {
           RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("expected expression after 'else', but statement is given") }
      | a[stmt_ty]=(pass_stmt|break_stmt|continue_stmt) 'if' b=disjunction 'else' c=simple_stmt {
           RAISE_SYNTAX_ERROR_KNOWN_LOCATION (a, "expected expression before 'if', but statement is given") }
      | a='lambda' [lambda_params] b=':' &FSTRING_MIDDLE  {
           RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "f-string: lambda expressions are not allowed without parentheses") }
      | a='lambda' [lambda_params] b=':' &TSTRING_MIDDLE  {
           RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "t-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 annotated_rhs {
           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_if_clause:
       | 'async'? 'for' (bitwise_or (',' bitwise_or)* [',']) !'in' {
           RAISE_SYNTAX_ERROR("'in' expected after for-loop variables") }

   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?") }
       | 'import' token=NEWLINE {
           RAISE_SYNTAX_ERROR_STARTING_FROM(token, "Expected one or more names after 'import'") }
   invalid_dotted_as_name:
       | dotted_name 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression {
           RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a,
               "cannot use %s as import target", _PyPegen_get_expr_name(a)) }
   invalid_import_from_as_name:
       | NAME 'as' !(NAME (',' | ')' | ';' | NEWLINE)) a=expression {
           RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a,
               "cannot use %s as import target", _PyPegen_get_expr_name(a)) }

   invalid_import_from_targets:
       | import_from_as_names ',' NEWLINE {
           RAISE_SYNTAX_ERROR("trailing comma not allowed without surrounding parentheses") }
       | token=NEWLINE {
           RAISE_SYNTAX_ERROR_STARTING_FROM(token, "Expected one or more names after 'import'") }

   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 when using 'as'") }
       | a='except' expression ['as' NAME ] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
       | a='except' NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
       | 'except' expression 'as' a=expression ':' block {
           RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
               a, "cannot use except statement with %s", _PyPegen_get_expr_name(a)) }
   invalid_except_star_stmt:
       | 'except' '*' a=expression ',' expressions 'as' NAME  ':' {
           RAISE_SYNTAX_ERROR_STARTING_FROM(a, "multiple exception types must be parenthesized when using 'as'") }
       | a='except' '*' expression ['as' NAME ] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
       | a='except' '*' (NEWLINE | ':') { RAISE_SYNTAX_ERROR("expected one or more exception types") }
       | 'except' '*' expression 'as' a=expression ':' block {
           RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
               a, "cannot use except* statement with %s", _PyPegen_get_expr_name(a)) }
   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' a=expression {
           RAISE_SYNTAX_ERROR_KNOWN_LOCATION(
               a, "cannot use %s as pattern target", _PyPegen_get_expr_name(a)) }
   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) }
       | 'else' ':' block 'elif' { RAISE_SYNTAX_ERROR("'elif' block follows an 'else' block")}
   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 [type_params] '(' [params] ')' ['->' expression] ':' NEWLINE !INDENT {
           RAISE_INDENTATION_ERROR("expected an indented block after function definition on line %d", a->lineno) }
       | ['async'] 'def' NAME [type_params] &&'(' [params] ')' ['->' expression] &&':' [func_type_comment] block
   invalid_class_def_raw:
       | 'class' NAME [type_params] ['(' [arguments] ')'] NEWLINE { RAISE_SYNTAX_ERROR("expected ':'") }
       | a='class' NAME [type_params] ['(' [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_unpacking:
       | a='*' expression '=' b=expression { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "cannot assign to iterable argument unpacking") }
   invalid_starred_expression:
       | '*' { RAISE_SYNTAX_ERROR("Invalid star expression") }

   invalid_fstring_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 '}'") }
       | '{' !annotated_rhs { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting a valid expression after '{'") }
       | '{' annotated_rhs !('=' | '!' | ':' | '}') {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '=', or '!', or ':', or '}'") }
       | '{' annotated_rhs '=' !('!' | ':' | '}') {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '!', or ':', or '}'") }
       | '{' annotated_rhs '='? invalid_fstring_conversion_character
       | '{' annotated_rhs '='? ['!' NAME] !(':' | '}') {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting ':' or '}'") }
       | '{' annotated_rhs '='? ['!' NAME] ':' fstring_format_spec* !'}' {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}', or format specs") }
       | '{' annotated_rhs '='? ['!' NAME] !'}' {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("f-string: expecting '}'") }

   invalid_fstring_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") }

   invalid_tstring_replacement_field:
       | '{' a='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before '='") }
       | '{' a='!' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before '!'") }
       | '{' a=':' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before ':'") }
       | '{' a='}' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "t-string: valid expression required before '}'") }
       | '{' !annotated_rhs { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting a valid expression after '{'") }
       | '{' annotated_rhs !('=' | '!' | ':' | '}') {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '=', or '!', or ':', or '}'") }
       | '{' annotated_rhs '=' !('!' | ':' | '}') {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '!', or ':', or '}'") }
       | '{' annotated_rhs '='? invalid_tstring_conversion_character
       | '{' annotated_rhs '='? ['!' NAME] !(':' | '}') {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting ':' or '}'") }
       | '{' annotated_rhs '='? ['!' NAME] ':' fstring_format_spec* !'}' {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '}', or format specs") }
       | '{' annotated_rhs '='? ['!' NAME] !'}' {
           PyErr_Occurred() ? NULL : RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: expecting '}'") }

   invalid_tstring_conversion_character:
       | '!' &(':' | '}') { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: missing conversion character") }
       | '!' !NAME { RAISE_SYNTAX_ERROR_ON_NEXT_TOKEN("t-string: invalid conversion character") }

   invalid_string_tstring_concat:
       | a=(fstring|string)+ b[expr_ty]=tstring {
           RAISE_SYNTAX_ERROR_KNOWN_RANGE(PyPegen_last_item(a, expr_ty), b, "cannot mix t-string literals with string or bytes literals") }
       | a=tstring+ b[expr_ty]=(fstring|string) {
           RAISE_SYNTAX_ERROR_KNOWN_RANGE(PyPegen_last_item(a, expr_ty), b, "cannot mix t-string literals with string or bytes literals") }

   invalid_arithmetic:
       | sum ('+'|'-'|'*'|'/'|'%'|'//'|'@') a='not' b=inversion { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "'not' after an operator must be parenthesized") }
   invalid_factor:
       | ('+' | '-' | '~') a='not' b=factor { RAISE_SYNTAX_ERROR_KNOWN_RANGE(a, b, "'not' after an operator must be parenthesized") }

   invalid_type_params:
       | '[' token=']' {
           RAISE_SYNTAX_ERROR_STARTING_FROM(
               token,
               "Type parameter list cannot be empty")}
