# Simplified grammar for Python

@bytecode True

@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 &(';' | NEWLINE) { _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

| call_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

# Another easter egg -- try 'print 2+2'

call_stmt[stmt_ty]:

| a=simple_primary &(NAME | NUMBER | STRING) b=args {

_Py_Expr(_Py_Call(a,

(b) ? ((expr_ty) b)->v.Call.args : NULL,

(b) ? ((expr_ty) b)->v.Call.keywords : NULL,

EXTRA), EXTRA) }

simple_primary[expr_ty]:

| a=simple_primary '.' b=NAME { _Py_Attribute(a, b->v.Name.id, Load, EXTRA) }

| a=simple_primary b=genexp &('.'|'('|'[') { _Py_Call(a, CHECK(_PyPegen_singleton_seq(p, b)), NULL, EXTRA) }

| a=simple_primary '(' b=[arguments] ')' &('.'|'('|'[') {

_Py_Call(a,

(b) ? ((expr_ty) b)->v.Call.args : NULL,

(b) ? ((expr_ty) b)->v.Call.keywords : NULL,

EXTRA) }

| a=simple_primary '[' b=slices ']' &('.'|'('|'[') { _Py_Subscript(a, b, Load, EXTRA) }

| NAME

# 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 { _Py_Delete(a, EXTRA) }

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)) }

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 o=['as' t=target { t }] { _Py_withitem(e, o, 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

expressions_list[asdl_seq*]: a=','.star_expression+ [','] { a }

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_parameters] ':' b=expression { _Py_Lambda((a) ? a : CHECK(_PyPegen_empty_arguments(p)), b, EXTRA) }

# 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) ? 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]:

| 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) }

| '__new_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 }

genexp[expr_ty]:

| '(' a=expression b=for_if_clauses ')' { _Py_GeneratorExp(a, b, EXTRA) }

| invalid_comprehension

set[expr_ty]: '{' a=expressions_list '}' { _Py_Set(a, EXTRA) }

setcomp[expr_ty]:

| '{' a=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) }

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 }

| incorrect_arguments

args[expr_ty]:

| a=starred_expression b=[',' c=args { c }] {

_Py_Call(_PyPegen_dummy_name(p),

(b) ? CHECK(_PyPegen_seq_insert_in_front(p, a, ((expr_ty) b)->v.Call.args))

: CHECK(_PyPegen_singleton_seq(p, a)),

(b) ? ((expr_ty) b)->v.Call.keywords : NULL,

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) }

| a=named_expression b=[',' c=args { c }] {

_Py_Call(_PyPegen_dummy_name(p),

(b) ? CHECK(_PyPegen_seq_insert_in_front(p, a, ((expr_ty) b)->v.Call.args))

: CHECK(_PyPegen_singleton_seq(p, a)),

(b) ? ((expr_ty) b)->v.Call.keywords : NULL,

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_seq[asdl_seq*]: a=','.star_target+ [','] { a }

star_target[expr_ty] (memo):

| '*' a=(!'*' star_target) {

_Py_Starred(CHECK(_PyPegen_set_expr_context(p, a, Store)), Store, EXTRA) }

| 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=star_target ')' { _PyPegen_set_expr_context(p, a, Store) }

| '(' a=[star_targets_seq] ')' { _Py_Tuple(a, Store, EXTRA) }

| '[' a=[star_targets_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 }

# The lookaheads to del_target_end ensure that we don't match expressions where a prefix of the

# expression matches our rule, thereby letting these cases fall through to invalid_del_target.

del_target[expr_ty] (memo):

| a=t_primary '.' b=NAME &del_target_end { _Py_Attribute(a, b->v.Name.id, Del, EXTRA) }

| a=t_primary '[' b=slices ']' &del_target_end { _Py_Subscript(a, b, Del, EXTRA) }

| del_t_atom

del_t_atom[expr_ty]:

| a=NAME &del_target_end { _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) }

| invalid_del_target

del_target_end: ')' | ']' | ',' | ';' | NEWLINE

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

incorrect_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:

| a=expression '=' {

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=list ':' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "only single target (not list) can be annotated") }

| a=tuple ':' { RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "only single target (not tuple) can be annotated") }

| a=star_named_expression ',' star_named_expressions* ':' {

RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "only single target (not tuple) can be annotated") }

| a=expression ':' expression ['=' annotated_rhs] {

RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "illegal target for annotation") }

| (star_targets '=')* a=star_expressions '=' {

RAISE_SYNTAX_ERROR_KNOWN_LOCATION(

_PyPegen_get_invalid_target(a),

"cannot assign to %s", _PyPegen_get_expr_name(_PyPegen_get_invalid_target(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_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") }

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_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_del_target:

| a=star_expression &del_target_end {

RAISE_SYNTAX_ERROR_KNOWN_LOCATION(a, "cannot delete %s", _PyPegen_get_expr_name(a)) }

invalid_import_from_targets:

| import_from_as_names ',' {

RAISE_SYNTAX_ERROR("trailing comma not allowed without surrounding parentheses") }