Dylan 008bbfdf5a Disallow implicit concatenation of t-strings and other string types (#19485) ... As of [this cpython PR](https://github.com/python/cpython/pull/135996), it is not allowed to concatenate t-strings with non-t-strings, implicitly or explicitly. Expressions such as `"foo" t"{bar}"` are now syntax errors. This PR updates some AST nodes and parsing to reflect this change. The structural change is that `TStringPart` is no longer needed, since, as in the case of `BytesStringLiteral`, the only possibilities are that we have a single `TString` or a vector of such (representing an implicit concatenation of t-strings). This removes a level of nesting from many AST expressions (which is what all the snapshot changes reflect), and simplifies some logic in the implementation of visitors, for example. The other change of note is in the parser. When we meet an implicit concatenation of string-like literals, we now count the number of t-string literals. If these do not exhaust the total number of implicitly concatenated pieces, then we emit a syntax error. To recover from this syntax error, we encode any t-string pieces as _invalid_ string literals (which means we flag them as invalid, record their range, and record the value as `""`). Note that if at least one of the pieces is an f-string we prefer to parse the entire string as an f-string; otherwise we parse it as a string. This logic is exactly the same as how we currently treat `BytesStringLiteral` parsing and error recovery - and carries with it the same pros and cons. Finally, note that I have not implemented any changes in the implementation of the formatter. As far as I can tell, none are needed. I did change a few of the fixtures so that we are always concatenating t-strings with t-strings.		2025-07-27 12:41:03 +00:00
..
ann_assign_stmt_invalid_annotation.py
ann_assign_stmt_invalid_target.py
ann_assign_stmt_invalid_value.py
ann_assign_stmt_missing_rhs.py
ann_assign_stmt_type_alias_annotation.py
args_unparenthesized_generator.py	[parser] Flag single unparenthesized generator expr with trailing comma in arguments. (#17893)	2025-05-07 14:11:35 -04:00
assert_empty_msg.py
assert_empty_test.py
assert_invalid_msg_expr.py
assert_invalid_test_expr.py
assign_stmt_invalid_target.py
assign_stmt_invalid_value_expr.py	[syntax-errors] Detect single starred expression assignment x = *y (#17624)	2025-04-30 15:04:00 -04:00
assign_stmt_keyword_target.py
assign_stmt_missing_rhs.py
assign_stmt_starred_expr_value.py	[syntax-errors] Detect single starred expression assignment x = *y (#17624)	2025-04-30 15:04:00 -04:00
async_unexpected_token.py	Maintain synchronicity between the lexer and the parser (#11457)	2024-06-03 18:23:50 +05:30
aug_assign_stmt_invalid_target.py
aug_assign_stmt_invalid_value.py
aug_assign_stmt_missing_rhs.py
case_expect_indented_block.py	Expect indented case block instead of match stmt (#11033)	2024-04-19 16:46:15 +05:30
class_def_empty_body.py
class_def_missing_name.py
class_def_unclosed_type_param_list.py
class_type_params_py311.py	[syntax-errors] Type parameter lists before Python 3.12 (#16479)	2025-03-05 13:19:09 +00:00
clause_expect_indented_block.py
clause_expect_single_statement.py
comma_separated_missing_comma.py	Implement re-lexing logic for better error recovery (#11845)	2024-06-17 06:47:00 +00:00
comma_separated_missing_comma_between_elements.py	Implement re-lexing logic for better error recovery (#11845)	2024-06-17 06:47:00 +00:00
comma_separated_missing_element_between_commas.py	Implement re-lexing logic for better error recovery (#11845)	2024-06-17 06:47:00 +00:00
comma_separated_missing_first_element.py	Implement re-lexing logic for better error recovery (#11845)	2024-06-17 06:47:00 +00:00
comprehension_missing_for_after_async.py
debug_shadow_class.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
debug_shadow_function.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
debug_shadow_import.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
debug_shadow_match.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
debug_shadow_try.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
debug_shadow_type_alias.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
debug_shadow_with.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
decorator_await_expression_py38.py	[syntax-errors] Improve error message and range for pre-PEP-614 decorator syntax errors (#16581)	2025-03-17 11:17:27 +00:00
decorator_dict_literal_py38.py	[syntax-errors] Improve error message and range for pre-PEP-614 decorator syntax errors (#16581)	2025-03-17 11:17:27 +00:00
decorator_expression_py38.py	[syntax-errors] Named expressions in decorators before Python 3.9 (#16386)	2025-03-05 17:08:18 +00:00
decorator_float_literal_py38.py	[syntax-errors] Improve error message and range for pre-PEP-614 decorator syntax errors (#16581)	2025-03-17 11:17:27 +00:00
decorator_invalid_expression.py
decorator_missing_expression.py
decorator_missing_newline.py
decorator_named_expression_py37.py	[syntax-errors] Named expressions in decorators before Python 3.9 (#16386)	2025-03-05 17:08:18 +00:00
decorator_non_toplevel_call_expression_py38.py	[syntax-errors] Improve error message and range for pre-PEP-614 decorator syntax errors (#16581)	2025-03-17 11:17:27 +00:00
decorator_unexpected_token.py
del_debug_py39.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00
del_incomplete_target.py
del_stmt_empty.py
dotted_name_multiple_dots.py
duplicate_match_class_attr.py	[syntax-errors] Duplicate attributes in match class pattern (#17186)	2025-04-03 17:55:37 -04:00
duplicate_match_key.py	[syntax-errors] Duplicate attributes in match class pattern (#17186)	2025-04-03 17:55:37 -04:00
duplicate_type_parameter_names.py	[syntax-errors] Duplicate type parameter names (#16858)	2025-03-21 15:06:22 -04:00
except_star_py310.py	[syntax-errors] Limit except* range to * (#16473)	2025-03-04 16:50:09 +00:00
except_stmt_invalid_expression.py
except_stmt_missing_as_name.py
except_stmt_missing_exception.py
except_stmt_missing_exception_and_as_name.py
except_stmt_unparenthesized_tuple_as.py	Make syntax error for unparenthesized except tuples version specific to before 3.14 (#17660)	2025-04-29 07:55:30 -05:00
except_stmt_unparenthesized_tuple_no_as_py313.py	Make syntax error for unparenthesized except tuples version specific to before 3.14 (#17660)	2025-04-29 07:55:30 -05:00
f_string_conversion_follows_exclamation.py	Add syntax error when conversion flag does not immediately follow exclamation mark (#18706)	2025-06-16 11:44:42 -05:00
f_string_empty_expression.py
f_string_invalid_conversion_flag_name_tok.py
f_string_invalid_conversion_flag_other_tok.py
f_string_invalid_starred_expr.py
f_string_lambda_without_parentheses.py
f_string_unclosed_lbrace.py
f_string_unclosed_lbrace_in_format_spec.py
for_iter_unpack_py38.py	[syntax-errors] Tuple unpacking in for statement iterator clause before Python 3.9 (#16558)	2025-03-13 15:55:17 -04:00
for_stmt_invalid_iter_expr.py
for_stmt_invalid_target.py	Add ExpressionContext for expression parsing (#11055)	2024-04-23 04:19:05 +00:00
for_stmt_invalid_target_binary_expr.py	Add ExpressionContext for expression parsing (#11055)	2024-04-23 04:19:05 +00:00
for_stmt_invalid_target_in_keyword.py	Add ExpressionContext for expression parsing (#11055)	2024-04-23 04:19:05 +00:00
for_stmt_missing_in_keyword.py
for_stmt_missing_iter.py
for_stmt_missing_target.py
from_import_dotted_names.py
from_import_empty_names.py
from_import_missing_module.py
from_import_missing_rpar.py
from_import_star_with_other_names.py
from_import_unparenthesized_trailing_comma.py
function_def_empty_body.py
function_def_invalid_return_expr.py
function_def_missing_identifier.py
function_def_missing_return_type.py
function_def_unclosed_parameter_list.py
function_def_unclosed_type_param_list.py
function_def_unparenthesized_return_types.py
function_type_params_py311.py	[syntax-errors] Type parameter lists before Python 3.12 (#16479)	2025-03-05 13:19:09 +00:00
global_stmt_empty.py
global_stmt_expression.py
global_stmt_trailing_comma.py
if_stmt_elif_missing_colon.py
if_stmt_empty_body.py
if_stmt_invalid_elif_test_expr.py
if_stmt_invalid_test_expr.py
if_stmt_missing_colon.py
if_stmt_missing_test.py
if_stmt_misspelled_elif.py
implicitly_concatenated_unterminated_string.py
implicitly_concatenated_unterminated_string_multiline.py
import_alias_missing_asname.py
import_stmt_empty.py
import_stmt_parenthesized_names.py
import_stmt_star_import.py
import_stmt_trailing_comma.py
invalid_annotation_class.py	[syntax-errors] Extend annotation checks to await (#17282)	2025-04-08 08:55:43 -04:00
invalid_annotation_function.py	[syntax-errors] Extend annotation checks to await (#17282)	2025-04-08 08:55:43 -04:00
invalid_annotation_function_py314.py	[syntax-errors] Extend annotation checks to await (#17282)	2025-04-08 08:55:43 -04:00
invalid_annotation_py314.py	[syntax-errors] Check annotations in annotated assignments (#17283)	2025-04-08 08:56:25 -04:00
invalid_annotation_type_alias.py	[syntax-errors] Extend annotation checks to await (#17282)	2025-04-08 08:55:43 -04:00
invalid_byte_literal.py
invalid_del_target.py
invalid_fstring_literal_element.py
invalid_string_literal.py
irrefutable_case_pattern.py	[syntax-errors] Irrefutable case pattern before final case (#16905)	2025-03-26 12:27:16 -04:00
iter_unpack_return_py37.py	[syntax-errors] Tuple unpacking in return and yield before Python 3.8 (#16485)	2025-03-06 11:57:20 -05:00
iter_unpack_yield_py37.py	[syntax-errors] Tuple unpacking in return and yield before Python 3.8 (#16485)	2025-03-06 11:57:20 -05:00
lambda_body_with_starred_expr.py
lambda_body_with_yield_expr.py
match_before_py310.py	Allow passing ParseOptions to inline tests (#16357)	2025-02-27 10:23:15 -05:00
match_classify_as_keyword.py	Maintain synchronicity between the lexer and the parser (#11457)	2024-06-03 18:23:50 +05:30
match_classify_as_keyword_or_identifier.py	Maintain synchronicity between the lexer and the parser (#11457)	2024-06-03 18:23:50 +05:30
match_expected_colon.py	Maintain synchronicity between the lexer and the parser (#11457)	2024-06-03 18:23:50 +05:30
match_stmt_expect_indented_block.py
match_stmt_expected_case_block.py
match_stmt_invalid_guard_expr.py
match_stmt_invalid_subject_expr.py
match_stmt_missing_guard_expr.py
match_stmt_missing_pattern.py	Maintain synchronicity between the lexer and the parser (#11457)	2024-06-03 18:23:50 +05:30
match_stmt_no_newline_before_case.py
match_stmt_single_starred_subject.py
mixed_bytes_and_non_bytes_literals.py
multiple_assignment_in_case_pattern.py	[syntax-errors] Fix multiple assignment for class keyword argument (#17184)	2025-04-03 17:32:39 -04:00
multiple_clauses_on_same_line.py
named_expr_slice.py	[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)	2025-03-14 15:06:42 -04:00
named_expr_slice_parse_error.py	[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)	2025-03-14 15:06:42 -04:00
nested_async_comprehension_py310.py	[syntax-errors] Async comprehension in sync comprehension (#17177)	2025-04-08 12:50:52 -04:00
node_range_with_gaps.py	Use empty range when there's "gap" in token source (#11032)	2024-04-19 11:36:26 +00:00
nonlocal_declaration_at_module_level.py	[syntax-errors] nonlocal declaration at module level (#17559)	2025-04-24 16:11:46 -04:00
nonlocal_stmt_empty.py	[syntax-errors] nonlocal declaration at module level (#17559)	2025-04-24 16:11:46 -04:00
nonlocal_stmt_expression.py	[syntax-errors] nonlocal declaration at module level (#17559)	2025-04-24 16:11:46 -04:00
nonlocal_stmt_trailing_comma.py	[syntax-errors] nonlocal declaration at module level (#17559)	2025-04-24 16:11:46 -04:00
param_missing_annotation.py
param_missing_default.py
param_with_invalid_annotation.py
param_with_invalid_default.py
param_with_invalid_star_annotation.py
param_with_star_annotation_py310.py	[syntax-errors] Star annotations before Python 3.11 (#16545)	2025-03-14 15:20:44 +00:00
params_duplicate_names.py
params_expected_after_star_separator.py
params_kwarg_after_star_separator.py
params_multiple_kwargs.py
params_multiple_slash_separator.py
params_multiple_star_separator.py
params_multiple_varargs.py
params_no_arg_before_slash.py
params_non_default_after_default.py
params_star_after_slash.py
params_star_separator_after_star_param.py
params_var_keyword_with_default.py
params_var_positional_with_default.py
parenthesized_context_manager_py38.py	[syntax-errors] Parenthesized context managers before Python 3.9 (#16523)	2025-03-17 08:54:55 -04:00
parenthesized_kwarg_py38.py	[syntax-errors] Parenthesized keyword argument names after Python 3.8 (#16482)	2025-03-06 12:18:13 -05:00
pep701_f_string_py311.py	[syntax-errors] PEP 701 f-strings before Python 3.12 (#16543)	2025-03-18 11:12:15 -04:00
pos_only_py37.py	[syntax-errors] Positional-only parameters before Python 3.8 (#16481)	2025-03-05 13:46:43 +00:00
raise_stmt_from_without_exc.py	Modify parsing of raise with cause when exception is absent (#15049)	2024-12-19 13:36:32 +00:00
raise_stmt_invalid_cause.py
raise_stmt_invalid_exc.py
raise_stmt_unparenthesized_tuple_cause.py
raise_stmt_unparenthesized_tuple_exc.py
rebound_comprehension_variable.py	[syntax-errors] Start detecting compile-time syntax errors (#16106)	2025-03-21 14:45:25 -04:00
return_stmt_invalid_expr.py
simple_and_compound_stmt_on_same_line.py
simple_and_compound_stmt_on_same_line_in_block.py
simple_stmts_on_same_line.py
simple_stmts_on_same_line_in_block.py
single_star_for.py	[syntax-errors] Starred expressions in return, yield, and for (#17134)	2025-04-02 08:38:25 -04:00
single_star_return.py	[syntax-errors] Starred expressions in return, yield, and for (#17134)	2025-04-02 08:38:25 -04:00
single_star_yield.py	[syntax-errors] Starred expressions in return, yield, and for (#17134)	2025-04-02 08:38:25 -04:00
single_starred_assignment_target.py	[syntax-errors] Single starred assignment target (#17024)	2025-03-29 12:35:47 -04:00
star_index_py310.py	[syntax-errors] Star expression in index before Python 3.11 (#16544)	2025-03-14 14:51:34 +00:00
star_slices.py	[syntax-errors] Star expression in index before Python 3.11 (#16544)	2025-03-14 14:51:34 +00:00
t_string_empty_expression.py	Implement template strings (#17851)	2025-05-30 15:00:56 -05:00
t_string_invalid_conversion_flag_name_tok.py	Implement template strings (#17851)	2025-05-30 15:00:56 -05:00
t_string_invalid_conversion_flag_other_tok.py	Implement template strings (#17851)	2025-05-30 15:00:56 -05:00
t_string_invalid_starred_expr.py	Implement template strings (#17851)	2025-05-30 15:00:56 -05:00
t_string_lambda_without_parentheses.py	Implement template strings (#17851)	2025-05-30 15:00:56 -05:00
t_string_unclosed_lbrace.py	Implement template strings (#17851)	2025-05-30 15:00:56 -05:00
t_string_unclosed_lbrace_in_format_spec.py	Implement template strings (#17851)	2025-05-30 15:00:56 -05:00
template_strings_py313.py	Disallow implicit concatenation of t-strings and other string types (#19485)	2025-07-27 12:41:03 +00:00
try_stmt_invalid_order.py
try_stmt_missing_except_finally.py
try_stmt_misspelled_except.py
try_stmt_mixed_except_kind.py	Raise syntax error for mixing except and except* (#14895)	2024-12-10 17:50:55 -06:00
tuple_context_manager_py38.py	[syntax-errors] Parenthesized context managers before Python 3.9 (#16523)	2025-03-17 08:54:55 -04:00
type_alias_incomplete_stmt.py
type_alias_invalid_value_expr.py
type_param_default_py312.py	[syntax-errors] Type parameter defaults before Python 3.13 (#16447)	2025-03-04 16:53:38 +00:00
type_param_invalid_bound_expr.py
type_param_missing_bound.py
type_param_param_spec_bound.py
type_param_param_spec_invalid_default_expr.py	Add support for PEP 696 syntax (#11120)	2024-04-26 09:47:29 +02:00
type_param_param_spec_missing_default.py	Add support for PEP 696 syntax (#11120)	2024-04-26 09:47:29 +02:00
type_param_type_var_invalid_default_expr.py	Add support for PEP 696 syntax (#11120)	2024-04-26 09:47:29 +02:00
type_param_type_var_missing_default.py	Add support for PEP 696 syntax (#11120)	2024-04-26 09:47:29 +02:00
type_param_type_var_tuple_bound.py
type_param_type_var_tuple_invalid_default_expr.py	Add support for PEP 696 syntax (#11120)	2024-04-26 09:47:29 +02:00
type_param_type_var_tuple_missing_default.py	Add support for PEP 696 syntax (#11120)	2024-04-26 09:47:29 +02:00
type_params_empty.py	Add syntax error for empty type parameter list (#12030)	2024-06-26 08:10:35 +05:30
type_stmt_py311.py	[syntax-errors] type alias statements before Python 3.12 (#16478)	2025-03-04 17:20:10 +00:00
unparenthesized_named_expr_index_py38.py	[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)	2025-03-14 15:06:42 -04:00
unparenthesized_named_expr_set_comp_py38.py	[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)	2025-03-14 15:06:42 -04:00
unparenthesized_named_expr_set_literal_py38.py	[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)	2025-03-14 15:06:42 -04:00
unterminated_fstring_newline_recovery.py
walrus_py37.py	[syntax-errors] Assignment expressions before Python 3.8 (#16383)	2025-02-28 17:13:46 -05:00
while_stmt_invalid_test_expr.py
while_stmt_missing_colon.py
while_stmt_missing_test.py
with_items_parenthesized_missing_colon.py	Use speculative parsing for with-items (#11770)	2024-06-06 08:59:56 +00:00
with_items_parenthesized_missing_comma.py
write_to_debug_expr.py	[syntax-errors] Store to or delete __debug__ (#16984)	2025-03-29 12:07:20 -04:00