# PEG grammar for Python 3.9 @trailer ''' void * _PyPegen_parse(Parser *p) { // Initialize keywords p->keywords = reserved_keywords; p->n_keyword_lists = n_keyword_lists; // Run parser void *result = NULL; if (p->start_rule == Py_file_input) { result = file_rule(p); } else if (p->start_rule == Py_single_input) { result = interactive_rule(p); } else if (p->start_rule == Py_eval_input) { result = eval_rule(p); } else if (p->start_rule == Py_func_type_input) { result = func_type_rule(p); } else if (p->start_rule == Py_fstring_input) { result = fstring_rule(p); } return result; } // The end ''' file[mod_ty]: a=[statements] ENDMARKER { _PyPegen_make_module(p, a) } interactive[mod_ty]: a=statement_newline { Interactive(a, p->arena) } eval[mod_ty]: a=expressions NEWLINE* ENDMARKER { Expression(a, p->arena) } func_type[mod_ty]: '(' a=[type_expressions] ')' '->' b=expression NEWLINE* ENDMARKER { FunctionType(a, b, p->arena) } fstring[expr_ty]: star_expressions # type_expressions allow */** but ignore them type_expressions[asdl_seq*]: | a=','.expression+ ',' '*' b=expression ',' '**' c=expression { _PyPegen_seq_append_to_end(p, CHECK(_PyPegen_seq_append_to_end(p, a, b)), c) } | a=','.expression+ ',' '*' b=expression { _PyPegen_seq_append_to_end(p, a, b) } | a=','.expression+ ',' '**' b=expression { _PyPegen_seq_append_to_end(p, a, b) } | '*' a=expression ',' '**' b=expression { _PyPegen_seq_append_to_end(p, CHECK(_PyPegen_singleton_seq(p, a)), b) } | '*' a=expression { _PyPegen_singleton_seq(p, a) } | '**' a=expression { _PyPegen_singleton_seq(p, a) } | ','.expression+ statements[asdl_seq*]: a=statement+ { _PyPegen_seq_flatten(p, a) } statement[asdl_seq*]: a=compound_stmt { _PyPegen_singleton_seq(p, a) } | simple_stmt statement_newline[asdl_seq*]: | a=compound_stmt NEWLINE { _PyPegen_singleton_seq(p, a) } | simple_stmt | NEWLINE { _PyPegen_singleton_seq(p, CHECK(_Py_Pass(EXTRA))) } | ENDMARKER { _PyPegen_interactive_exit(p) } simple_stmt[asdl_seq*]: | a=small_stmt !';' NEWLINE { _PyPegen_singleton_seq(p, a) } # Not needed, there for speedup | a=';'.small_stmt+ [';'] NEWLINE { a } # NOTE: assignment MUST precede expression, else parsing a simple assignment # will throw a SyntaxError. small_stmt[stmt_ty] (memo): | assignment | e=star_expressions { _Py_Expr(e, EXTRA) } | &'return' return_stmt | &('import' | 'from') import_stmt | &'raise' raise_stmt | 'pass' { _Py_Pass(EXTRA) } | &'del' del_stmt | &'yield' yield_stmt | &'assert' assert_stmt | 'break' { _Py_Break(EXTRA) } | 'continue' { _Py_Continue(EXTRA) } | &'global' global_stmt | &'nonlocal' nonlocal_stmt compound_stmt[stmt_ty]: | &('def' | '@' | ASYNC) function_def | &'if' if_stmt | &('class' | '@') class_def | &('with' | ASYNC) with_stmt | &('for' | ASYNC) for_stmt | &'try' try_stmt | &'while' while_stmt # 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( 6, "Variable annotation syntax is", _Py_AnnAssign(CHECK(_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(6, "Variable annotations syntax is", _Py_AnnAssign(a, b, c, 0, EXTRA)) } | a=(z=star_targets '=' { z })+ b=(yield_expr | star_expressions) !'=' tc=[TYPE_COMMENT] { _Py_Assign(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) } | a=single_target b=augassign ~ c=(yield_expr | star_expressions) { _Py_AugAssign(a, b->kind, c, EXTRA) } | invalid_assignment augassign[AugOperator*]: | '+=' { _PyPegen_augoperator(p, Add) } | '-=' { _PyPegen_augoperator(p, Sub) } | '*=' { _PyPegen_augoperator(p, Mult) } | '@=' { CHECK_VERSION(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) } global_stmt[stmt_ty]: 'global' a=','.NAME+ { _Py_Global(CHECK(_PyPegen_map_names_to_ids(p, a)), EXTRA) } nonlocal_stmt[stmt_ty]: 'nonlocal' a=','.NAME+ { _Py_Nonlocal(CHECK(_PyPegen_map_names_to_ids(p, a)), EXTRA) } yield_stmt[stmt_ty]: y=yield_expr { _Py_Expr(y, EXTRA) } assert_stmt[stmt_ty]: 'assert' a=expression b=[',' z=expression { z }] { _Py_Assert(a, b, EXTRA) } del_stmt[stmt_ty]: | 'del' a=del_targets &(';' | NEWLINE) { _Py_Delete(a, EXTRA) } | invalid_del_stmt import_stmt[stmt_ty]: import_name | import_from import_name[stmt_ty]: 'import' a=dotted_as_names { _Py_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 { _Py_ImportFrom(b->v.Name.id, c, _PyPegen_seq_count_dots(a), EXTRA) } | 'from' a=('.' | '...')+ 'import' b=import_from_targets { _Py_ImportFrom(NULL, b, _PyPegen_seq_count_dots(a), EXTRA) } import_from_targets[asdl_seq*]: | '(' a=import_from_as_names [','] ')' { a } | import_from_as_names !',' | '*' { _PyPegen_singleton_seq(p, CHECK(_PyPegen_alias_for_star(p))) } | invalid_import_from_targets import_from_as_names[asdl_seq*]: | a=','.import_from_as_name+ { a } import_from_as_name[alias_ty]: | a=NAME b=['as' z=NAME { z }] { _Py_alias(a->v.Name.id, (b) ? ((expr_ty) b)->v.Name.id : NULL, p->arena) } dotted_as_names[asdl_seq*]: | a=','.dotted_as_name+ { a } dotted_as_name[alias_ty]: | a=dotted_name b=['as' z=NAME { z }] { _Py_alias(a->v.Name.id, (b) ? ((expr_ty) b)->v.Name.id : NULL, p->arena) } dotted_name[expr_ty]: | a=dotted_name '.' b=NAME { _PyPegen_join_names_with_dot(p, a, b) } | NAME if_stmt[stmt_ty]: | 'if' a=named_expression ':' b=block c=elif_stmt { _Py_If(a, b, CHECK(_PyPegen_singleton_seq(p, c)), EXTRA) } | 'if' a=named_expression ':' b=block c=[else_block] { _Py_If(a, b, c, EXTRA) } elif_stmt[stmt_ty]: | 'elif' a=named_expression ':' b=block c=elif_stmt { _Py_If(a, b, CHECK(_PyPegen_singleton_seq(p, c)), EXTRA) } | 'elif' a=named_expression ':' b=block c=[else_block] { _Py_If(a, b, c, EXTRA) } else_block[asdl_seq*]: 'else' ':' b=block { b } while_stmt[stmt_ty]: | 'while' a=named_expression ':' b=block c=[else_block] { _Py_While(a, b, c, EXTRA) } for_stmt[stmt_ty]: | 'for' t=star_targets 'in' ~ ex=star_expressions ':' tc=[TYPE_COMMENT] b=block el=[else_block] { _Py_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(5, "Async for loops are", _Py_AsyncFor(t, ex, b, el, NEW_TYPE_COMMENT(p, tc), EXTRA)) } | invalid_for_target with_stmt[stmt_ty]: | 'with' '(' a=','.with_item+ ','? ')' ':' b=block { _Py_With(a, b, NULL, EXTRA) } | 'with' a=','.with_item+ ':' tc=[TYPE_COMMENT] b=block { _Py_With(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA) } | ASYNC 'with' '(' a=','.with_item+ ','? ')' ':' b=block { CHECK_VERSION(5, "Async with statements are", _Py_AsyncWith(a, b, NULL, EXTRA)) } | ASYNC 'with' a=','.with_item+ ':' tc=[TYPE_COMMENT] b=block { CHECK_VERSION(5, "Async with statements are", _Py_AsyncWith(a, b, NEW_TYPE_COMMENT(p, tc), EXTRA)) } with_item[withitem_ty]: | e=expression 'as' t=star_target &(',' | ')' | ':') { _Py_withitem(e, t, p->arena) } | invalid_with_item | e=expression { _Py_withitem(e, NULL, p->arena) } try_stmt[stmt_ty]: | 'try' ':' b=block f=finally_block { _Py_Try(b, NULL, NULL, f, EXTRA) } | 'try' ':' b=block ex=except_block+ el=[else_block] f=[finally_block] { _Py_Try(b, ex, el, f, EXTRA) } except_block[excepthandler_ty]: | 'except' e=expression t=['as' z=NAME { z }] ':' b=block { _Py_ExceptHandler(e, (t) ? ((expr_ty) t)->v.Name.id : NULL, b, EXTRA) } | 'except' ':' b=block { _Py_ExceptHandler(NULL, NULL, b, EXTRA) } finally_block[asdl_seq*]: 'finally' ':' a=block { a } return_stmt[stmt_ty]: | 'return' a=[star_expressions] { _Py_Return(a, EXTRA) } raise_stmt[stmt_ty]: | 'raise' a=expression b=['from' z=expression { z }] { _Py_Raise(a, b, EXTRA) } | 'raise' { _Py_Raise(NULL, NULL, EXTRA) } 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]: | 'def' n=NAME '(' params=[params] ')' a=['->' z=expression { z }] ':' tc=[func_type_comment] b=block { _Py_FunctionDef(n->v.Name.id, (params) ? params : CHECK(_PyPegen_empty_arguments(p)), b, NULL, a, NEW_TYPE_COMMENT(p, tc), EXTRA) } | ASYNC 'def' n=NAME '(' params=[params] ')' a=['->' z=expression { z }] ':' tc=[func_type_comment] b=block { CHECK_VERSION( 5, "Async functions are", _Py_AsyncFunctionDef(n->v.Name.id, (params) ? params : CHECK(_PyPegen_empty_arguments(p)), b, NULL, a, NEW_TYPE_COMMENT(p, tc), EXTRA) ) } func_type_comment[Token*]: | NEWLINE t=TYPE_COMMENT &(NEWLINE INDENT) { t } # Must be followed by indented block | invalid_double_type_comments | TYPE_COMMENT params[arguments_ty]: | invalid_parameters | parameters parameters[arguments_ty]: | a=slash_no_default b=param_no_default* c=param_with_default* d=[star_etc] { _PyPegen_make_arguments(p, a, NULL, b, c, d) } | a=slash_with_default b=param_with_default* c=[star_etc] { _PyPegen_make_arguments(p, NULL, a, NULL, b, c) } | a=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_seq*]: | a=param_no_default+ '/' ',' { a } | a=param_no_default+ '/' &')' { a } slash_with_default[SlashWithDefault*]: | a=param_no_default* b=param_with_default+ '/' ',' { _PyPegen_slash_with_default(p, a, b) } | a=param_no_default* b=param_with_default+ '/' &')' { _PyPegen_slash_with_default(p, a, b) } star_etc[StarEtc*]: | '*' a=param_no_default 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) } | invalid_star_etc kwds[arg_ty]: '**' 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_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? { _Py_arg(a->v.Name.id, b, NULL, EXTRA) } annotation[expr_ty]: ':' a=expression { a } default[expr_ty]: '=' a=expression { a } decorators[asdl_seq*]: a=('@' f=named_expression NEWLINE { f })+ { a } 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]: | 'class' a=NAME b=['(' z=[arguments] ')' { z }] ':' c=block { _Py_ClassDef(a->v.Name.id, (b) ? ((expr_ty) b)->v.Call.args : NULL, (b) ? ((expr_ty) b)->v.Call.keywords : NULL, c, NULL, EXTRA) } block[asdl_seq*] (memo): | NEWLINE INDENT a=statements DEDENT { a } | simple_stmt | invalid_block star_expressions[expr_ty]: | a=star_expression b=(',' c=star_expression { c })+ [','] { _Py_Tuple(CHECK(_PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) } | a=star_expression ',' { _Py_Tuple(CHECK(_PyPegen_singleton_seq(p, a)), Load, EXTRA) } | star_expression star_expression[expr_ty] (memo): | '*' a=bitwise_or { _Py_Starred(a, Load, EXTRA) } | expression star_named_expressions[asdl_seq*]: a=','.star_named_expression+ [','] { a } star_named_expression[expr_ty]: | '*' a=bitwise_or { _Py_Starred(a, Load, EXTRA) } | named_expression named_expression[expr_ty]: | a=NAME ':=' ~ b=expression { _Py_NamedExpr(CHECK(_PyPegen_set_expr_context(p, a, Store)), b, EXTRA) } | expression !':=' | invalid_named_expression annotated_rhs[expr_ty]: yield_expr | star_expressions expressions[expr_ty]: | a=expression b=(',' c=expression { c })+ [','] { _Py_Tuple(CHECK(_PyPegen_seq_insert_in_front(p, a, b)), Load, EXTRA) } | a=expression ',' { _Py_Tuple(CHECK(_PyPegen_singleton_seq(p, a)), Load, EXTRA) } | expression expression[expr_ty] (memo): | a=disjunction 'if' b=disjunction 'else' c=expression { _Py_IfExp(b, a, c, EXTRA) } | disjunction | lambdef lambdef[expr_ty]: | 'lambda' a=[lambda_params] ':' b=expression { _Py_Lambda((a) ? a : CHECK(_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=lambda_param_no_default* c=lambda_param_with_default* d=[lambda_star_etc] { _PyPegen_make_arguments(p, a, NULL, b, c, d) } | a=lambda_slash_with_default b=lambda_param_with_default* c=[lambda_star_etc] { _PyPegen_make_arguments(p, NULL, a, NULL, b, c) } | a=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_seq*]: | a=lambda_param_no_default+ '/' ',' { a } | a=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, a, b) } | a=lambda_param_no_default* b=lambda_param_with_default+ '/' &':' { _PyPegen_slash_with_default(p, a, b) } lambda_star_etc[StarEtc*]: | '*' 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) } | invalid_lambda_star_etc lambda_kwds[arg_ty]: '**' 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 { _Py_arg(a->v.Name.id, NULL, NULL, EXTRA) } disjunction[expr_ty] (memo): | a=conjunction b=('or' c=conjunction { c })+ { _Py_BoolOp( Or, CHECK(_PyPegen_seq_insert_in_front(p, a, b)), EXTRA) } | conjunction conjunction[expr_ty] (memo): | a=inversion b=('and' c=inversion { c })+ { _Py_BoolOp( And, CHECK(_PyPegen_seq_insert_in_front(p, a, b)), EXTRA) } | inversion inversion[expr_ty] (memo): | 'not' a=inversion { _Py_UnaryOp(Not, a, EXTRA) } | comparison comparison[expr_ty]: | a=bitwise_or b=compare_op_bitwise_or_pair+ { _Py_Compare(a, CHECK(_PyPegen_get_cmpops(p, b)), CHECK(_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_or[expr_ty]: | a=bitwise_or '|' b=bitwise_xor { _Py_BinOp(a, BitOr, b, EXTRA) } | bitwise_xor bitwise_xor[expr_ty]: | a=bitwise_xor '^' b=bitwise_and { _Py_BinOp(a, BitXor, b, EXTRA) } | bitwise_and bitwise_and[expr_ty]: | a=bitwise_and '&' b=shift_expr { _Py_BinOp(a, BitAnd, b, EXTRA) } | shift_expr shift_expr[expr_ty]: | a=shift_expr '<<' b=sum { _Py_BinOp(a, LShift, b, EXTRA) } | a=shift_expr '>>' b=sum { _Py_BinOp(a, RShift, b, EXTRA) } | sum sum[expr_ty]: | a=sum '+' b=term { _Py_BinOp(a, Add, b, EXTRA) } | a=sum '-' b=term { _Py_BinOp(a, Sub, b, EXTRA) } | term term[expr_ty]: | a=term '*' b=factor { _Py_BinOp(a, Mult, b, EXTRA) } | a=term '/' b=factor { _Py_BinOp(a, Div, b, EXTRA) } | a=term '//' b=factor { _Py_BinOp(a, FloorDiv, b, EXTRA) } | a=term '%' b=factor { _Py_BinOp(a, Mod, b, EXTRA) } | a=term '@' b=factor { CHECK_VERSION(5, "The '@' operator is", _Py_BinOp(a, MatMult, b, EXTRA)) } | factor factor[expr_ty] (memo): | '+' a=factor { _Py_UnaryOp(UAdd, a, EXTRA) } | '-' a=factor { _Py_UnaryOp(USub, a, EXTRA) } | '~' a=factor { _Py_UnaryOp(Invert, a, EXTRA) } | power power[expr_ty]: | a=await_primary '**' b=factor { _Py_BinOp(a, Pow, b, EXTRA) } | await_primary await_primary[expr_ty] (memo): | AWAIT a=primary { CHECK_VERSION(5, "Await expressions are", _Py_Await(a, EXTRA)) } | primary primary[expr_ty]: | invalid_primary # must be before 'primay genexp' because of invalid_genexp | a=primary '.' b=NAME { _Py_Attribute(a, b->v.Name.id, Load, EXTRA) } | a=primary b=genexp { _Py_Call(a, CHECK(_PyPegen_singleton_seq(p, b)), NULL, EXTRA) } | a=primary '(' b=[arguments] ')' { _Py_Call(a, (b) ? ((expr_ty) b)->v.Call.args : NULL, (b) ? ((expr_ty) b)->v.Call.keywords : NULL, EXTRA) } | a=primary '[' b=slices ']' { _Py_Subscript(a, b, Load, EXTRA) } | atom slices[expr_ty]: | a=slice !',' { a } | a=','.slice+ [','] { _Py_Tuple(a, Load, EXTRA) } slice[expr_ty]: | a=[expression] ':' b=[expression] c=[':' d=[expression] { d }] { _Py_Slice(a, b, c, EXTRA) } | a=expression { a } atom[expr_ty]: | NAME | 'True' { _Py_Constant(Py_True, NULL, EXTRA) } | 'False' { _Py_Constant(Py_False, NULL, EXTRA) } | 'None' { _Py_Constant(Py_None, NULL, EXTRA) } | '__peg_parser__' { RAISE_SYNTAX_ERROR("You found it!") } | &STRING strings | NUMBER | &'(' (tuple | group | genexp) | &'[' (list | listcomp) | &'{' (dict | set | dictcomp | setcomp) | '...' { _Py_Constant(Py_Ellipsis, NULL, EXTRA) } strings[expr_ty] (memo): a=STRING+ { _PyPegen_concatenate_strings(p, a) } list[expr_ty]: | '[' a=[star_named_expressions] ']' { _Py_List(a, Load, EXTRA) } listcomp[expr_ty]: | '[' a=named_expression ~ b=for_if_clauses ']' { _Py_ListComp(a, b, EXTRA) } | invalid_comprehension tuple[expr_ty]: | '(' a=[y=star_named_expression ',' z=[star_named_expressions] { _PyPegen_seq_insert_in_front(p, y, z) } ] ')' { _Py_Tuple(a, Load, EXTRA) } group[expr_ty]: | '(' a=(yield_expr | named_expression) ')' { a } | invalid_group genexp[expr_ty]: | '(' a=named_expression ~ b=for_if_clauses ')' { _Py_GeneratorExp(a, b, EXTRA) } | invalid_comprehension set[expr_ty]: '{' a=star_named_expressions '}' { _Py_Set(a, EXTRA) } setcomp[expr_ty]: | '{' a=named_expression ~ b=for_if_clauses '}' { _Py_SetComp(a, b, EXTRA) } | invalid_comprehension dict[expr_ty]: | '{' a=[double_starred_kvpairs] '}' { _Py_Dict(CHECK(_PyPegen_get_keys(p, a)), CHECK(_PyPegen_get_values(p, a)), EXTRA) } dictcomp[expr_ty]: | '{' a=kvpair b=for_if_clauses '}' { _Py_DictComp(a->key, a->value, b, EXTRA) } | invalid_dict_comprehension 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) } for_if_clauses[asdl_seq*]: | for_if_clause+ for_if_clause[comprehension_ty]: | ASYNC 'for' a=star_targets 'in' ~ b=disjunction c=('if' z=disjunction { z })* { CHECK_VERSION(6, "Async comprehensions are", _Py_comprehension(a, b, c, 1, p->arena)) } | 'for' a=star_targets 'in' ~ b=disjunction c=('if' z=disjunction { z })* { _Py_comprehension(a, b, c, 0, p->arena) } | invalid_for_target yield_expr[expr_ty]: | 'yield' 'from' a=expression { _Py_YieldFrom(a, EXTRA) } | 'yield' a=[star_expressions] { _Py_Yield(a, EXTRA) } arguments[expr_ty] (memo): | a=args [','] &')' { a } | invalid_arguments args[expr_ty]: | a=','.(starred_expression | named_expression !'=')+ b=[',' k=kwargs {k}] { _PyPegen_collect_call_seqs(p, a, b, EXTRA) } | a=kwargs { _Py_Call(_PyPegen_dummy_name(p), CHECK_NULL_ALLOWED(_PyPegen_seq_extract_starred_exprs(p, a)), CHECK_NULL_ALLOWED(_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]: | '*' a=expression { _Py_Starred(a, Load, EXTRA) } kwarg_or_starred[KeywordOrStarred*]: | a=NAME '=' b=expression { _PyPegen_keyword_or_starred(p, CHECK(_Py_keyword(a->v.Name.id, b, EXTRA)), 1) } | a=starred_expression { _PyPegen_keyword_or_starred(p, a, 0) } | invalid_kwarg kwarg_or_double_starred[KeywordOrStarred*]: | a=NAME '=' b=expression { _PyPegen_keyword_or_starred(p, CHECK(_Py_keyword(a->v.Name.id, b, EXTRA)), 1) } | '**' a=expression { _PyPegen_keyword_or_starred(p, CHECK(_Py_keyword(NULL, a, EXTRA)), 1) } | invalid_kwarg # 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 })* [','] { _Py_Tuple(CHECK(_PyPegen_seq_insert_in_front(p, a, b)), Store, EXTRA) } star_targets_list_seq[asdl_seq*]: a=','.star_target+ [','] { a } star_targets_tuple_seq[asdl_seq*]: | a=star_target b=(',' c=star_target { c })+ [','] { _PyPegen_seq_insert_in_front(p, a, b) } | a=star_target ',' { _PyPegen_singleton_seq(p, a) } star_target[expr_ty] (memo): | '*' a=(!'*' star_target) { _Py_Starred(CHECK(_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 { _Py_Attribute(a, b->v.Name.id, Store, EXTRA) } | a=t_primary '[' b=slices ']' !t_lookahead { _Py_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] ')' { _Py_Tuple(a, Store, EXTRA) } | '[' a=[star_targets_list_seq] ']' { _Py_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 { _Py_Attribute(a, b->v.Name.id, Store, EXTRA) } | a=t_primary '[' b=slices ']' !t_lookahead { _Py_Subscript(a, b, Store, EXTRA) } del_targets[asdl_seq*]: a=','.del_target+ [','] { a } del_target[expr_ty] (memo): | a=t_primary '.' b=NAME !t_lookahead { _Py_Attribute(a, b->v.Name.id, Del, EXTRA) } | a=t_primary '[' b=slices ']' !t_lookahead { _Py_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] ')' { _Py_Tuple(a, Del, EXTRA) } | '[' a=[del_targets] ']' { _Py_List(a, Del, EXTRA) } targets[asdl_seq*]: a=','.target+ [','] { a } target[expr_ty] (memo): | a=t_primary '.' b=NAME !t_lookahead { _Py_Attribute(a, b->v.Name.id, Store, EXTRA) } | a=t_primary '[' b=slices ']' !t_lookahead { _Py_Subscript(a, b, Store, EXTRA) } | t_atom t_primary[expr_ty]: | a=t_primary '.' b=NAME &t_lookahead { _Py_Attribute(a, b->v.Name.id, Load, EXTRA) } | a=t_primary '[' b=slices ']' &t_lookahead { _Py_Subscript(a, b, Load, EXTRA) } | a=t_primary b=genexp &t_lookahead { _Py_Call(a, CHECK(_PyPegen_singleton_seq(p, b)), NULL, EXTRA) } | a=t_primary '(' b=[arguments] ')' &t_lookahead { _Py_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: '(' | '[' | '.' t_atom[expr_ty]: | a=NAME { _PyPegen_set_expr_context(p, a, Store) } | '(' a=target ')' { _PyPegen_set_expr_context(p, a, Store) } | '(' b=[targets] ')' { _Py_Tuple(b, Store, EXTRA) } | '[' b=[targets] ']' { _Py_List(b, Store, EXTRA) } # From here on, there are rules for invalid syntax with specialised error messages invalid_arguments: | args ',' '*' { RAISE_SYNTAX_ERROR("iterable argument unpacking follows keyword argument unpacking") } | a=expression for_if_clauses ',' [args | expression for_if_clauses] { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "Generator expression must be parenthesized") } | a=args for_if_clauses { _PyPegen_nonparen_genexp_in_call(p, a) } | args ',' a=expression for_if_clauses { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "Generator expression must be parenthesized") } | a=args ',' args { _PyPegen_arguments_parsing_error(p, a) } invalid_kwarg: | !(NAME '=') a=expression b='=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION( a, "expression cannot contain assignment, perhaps you meant \"==\"?") } invalid_named_expression: | a=expression ':=' expression { RAISE_SYNTAX_ERROR_KNOWN_LOCATION( a, "cannot use assignment expressions with %s", _PyPegen_get_expr_name(a)) } invalid_assignment: | a=invalid_ann_assign_target ':' expression { RAISE_SYNTAX_ERROR_KNOWN_LOCATION( a, "only single target (not %s) can be annotated", _PyPegen_get_expr_name(a) )} | a=star_named_expression ',' star_named_expressions* ':' expression { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "only single target (not tuple) can be annotated") } | a=expression ':' expression { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "illegal target for annotation") } | (star_targets '=')* a=star_expressions '=' { RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) } | (star_targets '=')* a=yield_expr '=' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "assignment to yield expression not possible") } | a=star_expressions augassign (yield_expr | star_expressions) { RAISE_SYNTAX_ERROR_KNOWN_LOCATION( a, "'%s' is an illegal expression for augmented assignment", _PyPegen_get_expr_name(a) )} invalid_ann_assign_target[expr_ty]: | list | tuple | '(' a=invalid_ann_assign_target ')' { a } invalid_del_stmt: | 'del' a=star_expressions { RAISE_SYNTAX_ERROR_INVALID_TARGET(DEL_TARGETS, a) } invalid_block: | NEWLINE !INDENT { RAISE_INDENTATION_ERROR("expected an indented block") } invalid_primary: | primary a='{' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "invalid syntax") } invalid_comprehension: | ('[' | '(' | '{') a=starred_expression for_if_clauses { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "iterable unpacking cannot be used in comprehension") } 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: | param_no_default* (slash_with_default | param_with_default+) param_no_default { RAISE_SYNTAX_ERROR("non-default argument follows default argument") } invalid_lambda_parameters: | lambda_param_no_default* (lambda_slash_with_default | lambda_param_with_default+) lambda_param_no_default { RAISE_SYNTAX_ERROR("non-default argument follows default argument") } invalid_star_etc: | '*' (')' | ',' (')' | '**')) { RAISE_SYNTAX_ERROR("named arguments must follow bare *") } | '*' ',' TYPE_COMMENT { RAISE_SYNTAX_ERROR("bare * has associated type comment") } invalid_lambda_star_etc: | '*' (':' | ',' (':' | '**')) { RAISE_SYNTAX_ERROR("named arguments must follow bare *") } invalid_double_type_comments: | TYPE_COMMENT NEWLINE TYPE_COMMENT NEWLINE INDENT { RAISE_SYNTAX_ERROR("Cannot have two type comments on def") } invalid_with_item: | expression 'as' a=expression { RAISE_SYNTAX_ERROR_INVALID_TARGET(STAR_TARGETS, a) } invalid_for_target: | ASYNC? 'for' a=star_expressions { RAISE_SYNTAX_ERROR_INVALID_TARGET(FOR_TARGETS, a) } invalid_group: | '(' a=starred_expression ')' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "can't use starred expression here") } invalid_import_from_targets: | import_from_as_names ',' { RAISE_SYNTAX_ERROR("trailing comma not allowed without surrounding parentheses") }