Preserve newly merged Python 3.14 compatibility work before applying the three required final-3.15 contract adjustments exposed by merge CI.
Assisted-by: OpenAI Codex:model identifier unavailable
Track consumed positional arguments, including star width and precision, and preserve mapping key representations in decimal conversion diagnostics.
Assisted-by: OpenAI Codex:model identifier unavailable
* Match CPython's str subscript TypeError message
`str.__getitem__` with a non-index key raised the shared sequence
wording ("str indices must be integers or slices or classes that
override __index__ operator, not 'x'") instead of CPython's
str-specific "string indices must be integers, not 'x'" (bpo-44110 /
gh-88276, Python 3.11).
Add `SequenceIndex::try_from_borrowed_object_with_err`, which takes a
caller-supplied error closure, and have the existing
`try_from_borrowed_object` delegate to it with the unchanged shared
message. `str._getitem` now supplies the CPython-accurate message,
which flows through both `__getitem__` and the mapping subscript slot.
Other sequence types keep the shared wording.
Removes the expectedFailure marker on
`string_tests.StringLikeTest.test_subscript`, fixing it for both
test_str and test_userstring.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
* Fold str's subscript TypeError into the shared index helper
The previous commit added `SequenceIndex::try_from_borrowed_object_with_err`
(a closure-taking function) so `str` could raise CPython's
"string indices must be integers, not ..." message. Per review, a whole
helper API plus a thin wrapper was overkill for a single caller.
Instead, inline that one error case into `try_from_borrowed_object`: when
`type_name` is "str", raise the str-specific message; every other type keeps
the shared sequence wording. `str._getitem` goes back to the plain `match`
over `SequenceIndex` with no duplicated index parsing. A bad slice key
(e.g. `'a'[::'x']`) still surfaces the slice-specific error, since only the
non-index/non-slice branch is customized.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
* Truncate index TypeError type names to 200 characters
Route str's non-index TypeError through a function pointer
message helper. Sequence index errors use the same 200-character
type-name cap.
Assisted-by: Grok:4.6
* Encode sequence index TypeError names as type params
`&'static str` cannot be a const generic. SequenceIndexName
holds the name as an associated constant, matching ArgName.
Both str and sequence errors go through one fn(&str) -> String
and a cold TypeError helper.
Assisted-by: Grok:4.6
---------
Co-authored-by: Jaedeok Kim <rn.6d17s2@gmail.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
`PyStr::__add__` delegated to the right operand's `__radd__` whenever it had
one, and returned whatever came back. For every numeric type that is a
`NotImplemented`, which then reached the generic binary-op handler:
>>> "a" + 1
TypeError: unsupported operand type(s) for +: 'str' and 'int'
CPython falls back to `str`'s `sq_concat` once the reflected call declines, so
it names the concatenation instead:
TypeError: can only concatenate str (not "int") to str
The specific message was already here, but only reachable for operands with no
`__radd__` at all, so `list`, `object`, `bytes` and `None` were correct while
`int`, `float`, `bool` and any class with a declining `__radd__` were not.
A `__radd__` that returns a value still wins, unchanged.
Verified against CPython 3.14.0: the new snippet asserts the message for
`int`, `float`, `bool`, `list`, `None`, `bytes` and a declining `__radd__`,
and passes under both interpreters. Reverting only the `str.rs` change fails
its first assertion.
Assisted-by: Claude Code:claude-opus-5
`"a\tb".expandtabs(0)` panicked with a capacity overflow. CPython returns
`'ab'`: with no width to advance to, the tabs come out and nothing else
moves. `expandtabs(-1)` is the same call, since `ExpandTabsArgs::tabsize`
sends every negative value to 0.
`expandtabs` keeps the tab stop in `tab_size` and the current column in
`col_count`, and on a tab it does `tab_size - col_count`. With a tab size of
zero both start at 0, the first character makes `col_count` 1 while
`tab_size` stays 0, and the subtraction underflows. The run of spaces asked
for next is `usize::MAX`, and the allocation aborts the process. A tab has to
follow something on the line to reach it: `"\ta".expandtabs(0)` subtracts 0
from 0 and comes out right by accident.
`BytesInner::expandtabs` already returns early for this and filters the tabs
out. The string version now does the same.
Assisted-by: Claude Code:claude-opus-5
Wtf8::replace looks for the pattern with a byte search. An empty pattern
matches at every byte, so the replacement was inserted between the bytes of
a multi-byte character and the result was no longer WTF-8:
>>> "á".replace("", "-")
'-ím' # CPython: '-á-'
from_bytes_unchecked then took that as valid without looking, so every later
read of the string returned something else. An empty pattern now walks code
points instead. A pattern that is not empty stays on the byte search, which
is safe because a WTF-8 sequence never starts inside another one.
Assisted-by: Claude Code:claude-opus-5
* specialize: check the member descriptor's type before caching its slot offset
The LOAD_ATTR/STORE_ATTR specializations cached the slot offset of any member
descriptor found on the owner's type and then guarded the specialized
instruction on the type version alone, while descr_get()/descr_set() check on
every access that the instance belongs to the type the descriptor was defined
for. A descriptor taken from a wider class and bound to a narrower one read
past the instance's slot array once the cache warmed up:
class Big:
__slots__ = ("a0", "a1", "a2", "a3", "a4", "a5", "a6", "a7")
class Narrow:
__slots__ = ("z",)
Narrow.x = Big.__dict__["a7"]
o = Narrow()
for _ in range(1000):
try: o.x
except TypeError: pass
# index out of bounds: the len is 1 but the index is 7 (object/core.rs)
A class with no slots at all reached the ext_ref().unwrap() on the same line.
Assisted-by: Claude
* socket: reserve recv()'s buffer fallibly
recv() and recvfrom() handed the caller's bufsize straight to
Vec::with_capacity, so an unreachable size aborted the process through
handle_alloc_error before any syscall was made:
socket.socket().recv(2**62)
# memory allocation of 4611686018427387904 bytes failed -> SIGABRT
try_reserve_exact reports MemoryError instead, which is what CPython raises.
Assisted-by: Claude
* types: count the __call__ and __get__ slot dispatches as recursion
Both wrappers re-enter Python without pushing a frame, so nothing counted the
nesting when the special method named the object it was looked up on:
class C: pass
c = C(); C.__call__ = c
c() # native stack overflow, SIGSEGV
class D: pass
d = D(); D.__get__ = d; D.x = d
d.x # the same, through descr_get
with_recursion around the two dispatches raises RecursionError instead, the
way Py_EnterRecursiveCall bounds a tp_call dispatch. It costs about 5% on a
__call__ dispatch and 3% on a __get__ dispatch through these wrappers.
Assisted-by: Claude
* typevar: show a ParamSpecArgs origin by its repr
ParamSpecArgs and ParamSpecKwargs fell back to a Rust `{:?}` of __origin__ when
it had no __name__. That walks the object graph natively through Debug for
PyInner, where no recursion guard sits, so a single repr() of a deeply nested
chain overflowed the native stack:
a = object()
for _ in range(30000):
a = typing.ParamSpecArgs(a)
repr(a) # SIGSEGV
The origin is formatted with its repr now, which is guarded, and a ParamSpec
origin is recognized by its type rather than by carrying a __name__.
Assisted-by: Claude
* Do not hold a lock across a call back into Python
Three places kept a lock while running code that can reach the same object, so
a callback that touched it wedged the process:
_asyncio.future_add_to_awaited_by(fut, waiter) # waiter.__hash__ adds again
select.select(elements, [], [], 0) # fileno() clears `elements`
select.poll().poll(1000) # SIGALRM handler registers
The future's awaited-by field is read and written under its lock but the set is
built outside it, the list extraction re-reads the list on each step the way
map_iterable_object() does, and poll() waits on a copy of its descriptors. All
three ran forever before and now finish the way they do on CPython.
Assisted-by: Claude
* Validate memoryview.cast() arguments and export negative strides correctly
cast() accepted any struct format and any shape element. A zero-size
format ('0s') and a 0 in the shape both reached a division by zero;
cast() now takes only a native single character format, optionally
'@'-prefixed, and shape elements that are ints greater than zero.
A view with a negative stride starts at its last item, so the bytes it
exported began there and its own offsets walked off the front of them.
Such a view now exports the whole underlying buffer with `start` folded
into the descriptor's offsets, and zip_eq() hands over a whole run only
when both sides are contiguous in the last dimension.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* Charge native recursion to the stack, not to the frame limit
with_recursion() checked the limit sys.setrecursionlimit() sets and
incremented the same counter that pushing a frame does, so a guard on a
native dispatch spent what Python code had left to call with, and did so
where sys._getframe() cannot see it: test.support.get_recursion_available()
reported frames that were no longer there. Py_EnterRecursiveCall bounds
the native stack instead, which is a separate budget, and the C stack
check with_recursion already performs is that bound.
The snippets pinning the guarded paths nest deep enough to reach the
stack rather than the frame limit.
Assisted-by: Claude
* Report a size that cannot be allocated instead of aborting on it
A size taken from Python went straight into an infallible allocation in
several places, so the process aborted through handle_alloc_error before
any exception could be raised:
- str/bytes/bytearray center(), ljust(), rjust() and zfill() reserved
the padded result for the caller's width
- expandtabs() built its runs of spaces from a tabsize of any width;
the argument is a C int, and a wider one does not fit
- Buffered{Reader,Writer,Random} allocated buffer_size, and read(),
read1() and FileIO.read() their read size
- bytes(n) and bytearray(n) allocated n
- pbkdf2_hmac() allocated the derived key length, which is a C int
Each of these now reports MemoryError, or OverflowError where the
argument does not fit the type it is declared with.
new_zeroed_bytes() leaves the zeroing to the allocator, so a large
request costs the pages that are written to rather than all of them.
Assisted-by: Claude
* marshal: answer allow_code where a code object is written or read
allow_code was answered by walking the whole result a second time, with
no depth counter and no record of what it had already seen, so a value
that referred back to itself or nested deeply enough ran off the native
stack. w_object() and r_object() answer it where the code object is,
inside the walk that already bounds its depth and resolves references.
A container length is read the way r_long() reads one: it is signed, so
a length with the top bit set is out of range rather than four billion
items to reserve room for.
load() no longer holds a borrow of the buffer read() returned across the
seek() it makes afterwards.
Assisted-by: Claude
* Do not lock an object while running code that can reach it
Several places held a lock or a borrow of an object across a call back
into Python, so a callback that touched the same object waited on a lock
its own caller was holding:
- memoryview slice assignment read a source overlapping the destination,
and __setitem__ converted the value while holding the write borrow
- BytesIO.readinto() read into a buffer viewing the same BytesIO
- array.__setitem__ converted the value under the array's write lock,
and mmap.write() read a source viewing the same map
- bytearray.join() and bytearray.__mod__ drove Python with the
bytearray borrowed
- array and bytearray answered "is this resizable" after taking the
write lock, though an export is exactly a borrow someone else holds
A TextIOWrapper cookie now has to name a position inside what was
decoded in characters as well as in bytes; only the byte offset was
checked, and the character count is what read() and tell() index with.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* Stop asserting a pbkdf2 message that depends on the width of a C long
The snippet asserted "key length is too great.", which pbkdf2_hmac()
only reaches once the length has been converted; where a C long is
narrower than the length asked for, the conversion fails first and says
so instead. Both are OverflowError, which is what the case is about.
test_support.test_get_recursion_depth passes now that a native recursion
guard no longer spends frames get_recursion_depth() cannot see.
Assisted-by: Claude
* Publish and read the same pointer for a thread's top frame
set_current_frame() casts the `Py<FrameObject>` it publishes straight to
`*mut FrameObject`, so ThreadSlot::top_frame holds the object's base.
sys._current_frames() read it back through Py::from_payload_ptr(), which
subtracts the payload offset from what it is given. The reference it took
therefore incremented, and later decremented, a word 48 bytes ahead of
the frame -- inside the object allocated before it, whose OnceLock state
word sits exactly there for two frames adjacent in the size class. The
neighbour then read an initialized-looking cold pointer that had never
been written and locked whatever the uninitialized word addressed, so
the thread that owned it crashed rather than the one that read.
The slot now holds `*mut Py<FrameObject>`, which is what both sides mean.
A thread parked in a call has no FrameObject for its topmost frame, so
top_frame is null there and the reader takes the materialize path
instead: test_sys.test_current_frames never reaches the branch. The
snippet takes _current_frames() against threads that are running.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* Decide stop-the-world parking under the thread registry lock
do_suspend() published SUSPENDED first and only then re-read `requested`,
restoring itself to ATTACHED if the stop had ended in the meantime. That
made a thread the second writer able to leave SUSPENDED, so a stop whose
completion check had already observed the thread parked could be undone
behind the requester's back:
worker CAS ATTACHED -> SUSPENDED
requester all_non_requester_suspended() -> true, world_stopped = true
requester start_the_world(): requested = false, then walks the registry
worker reads requested == false, stores ATTACHED
With the store landing inside that walk the debug assertion in
start_the_world fires; with the walk already past the slot, a following
stop force-parks the thread DETACHED -> SUSPENDED, counts it as stopped,
and the store then puts it back to ATTACHED with the world declared
stopped and the thread running bytecode.
`requested` is set in init_thread_countdown() and cleared in
start_the_world() with the registry held, and start_the_world() keeps
holding it while releasing every SUSPENDED thread. Taking the registry
around the check and the transition therefore makes the two orders the
only ones possible: park before that release pass and be woken by it, or
find the request already withdrawn and stay ATTACHED. The requester is
left as the only writer that takes a thread out of SUSPENDED, and the
self-restore is gone.
suspend_if_needed() takes the VirtualMachine to reach the registry.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* Keep an atexit callback alive while it is being compared
atexit.unregister() releases the callback list around each __eq__ call and
identified the entry it had compared by the address of its Box. __eq__ can
call atexit._clear(), which drops that Box, and atexit.register(), whose
new Box lands on the freed allocation; the identity search then matched
the freshly registered callback and removed it.
atexit.register(a); atexit.register(b); atexit.register(c)
# __eq__ runs _clear() then register(d), returns True
atexit.unregister(probe)
left no callbacks registered where CPython leaves d.
Entries are Arc-shared now, so unregister() holds the one it is comparing
and matches it with Arc::ptr_eq: an address cannot be reused while the
comparison that named it is still running.
Assisted-by: Claude
* Hold atexit entries in PyRc rather than Arc
PyObjectRef is Send and Sync only under the threading feature, so an Arc
over a callback entry trips clippy::arc_with_non_send_sync in builds
without it, such as the wasm package. PyRc is Arc there and Rc otherwise.
Assisted-by: Claude
* Do not hold a buffer's storage while waiting for a peer
FileIO.readinto() and socket.recv_into()/recvfrom_into() took the target
buffer's write borrow and kept it for the whole call, including the wait
for data a pipe, socket or terminal may never deliver. What CPython holds
across that wait is the export, which only forbids resizing; the borrow is
a lock every other thread touching the same object waits on, so
threading.Thread(target=lambda: sock.recv_into(buf)).start()
len(buf)
did not answer until the peer sent. A thread parked on that lock is
ATTACHED and never reaches a safepoint, so gc.collect() in a third thread
waited for the peer as well: one incidental read of the buffer stopped the
world from being stopped at all.
The wait now runs against storage of its own and the bytes are copied over
once they arrive, with the export held throughout so the target still
cannot be resized meanwhile. A seekable file answers from itself rather
than from a peer, so FileIO.readinto() writes into the target directly
there and the buffered read path is unchanged.
Assisted-by: Claude
* Do not hold a buffer's storage while waiting to hand it over
socket.send()/sendall()/sendto()/sendmsg() and FileIO.write() kept the
source buffer's read borrow for the whole call, including the wait for a
peer that may never make room. That borrow is a lock every other thread
writing to the same object waits on, so
threading.Thread(target=lambda: sock.sendall(buf)).start()
buf[0] = 1
did not return until the peer read; and a thread parked there is ATTACHED
and never reaches a safepoint, so gc.collect() in a third thread waited
for the peer too -- the same wedge readinto() had on the receiving side.
ArgBytesLike::borrow_buf_unlocked() answers with bytes that survive the
borrow being dropped. An immutable object hands out a plain reference and
locks nothing, so those are sent where they lie and bytes and memoryviews
over them cost nothing; only bytes reached through a lock are copied out
first. The export is held throughout either way, so the source still
cannot be resized while it is being sent.
The regression snippet covers both directions now and is renamed for it.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* Check select()'s descriptor limit while the sequence is walked
seq2set() collected the whole sequence and compared the result's length
against FD_SETSIZE afterwards. Selectable::try_from_object() calls
fileno(), which runs Python and can append to the list being walked, and
the walk re-reads the list on every step, so the collection had no end to
reach and the comparison was never made. seq2set in Modules/selectmodule.c
checks the count per element instead.
stdlib_select.py gains a fileno() that appends to its own list, and
releases its sockets with close() rather than by dropping the name.
Assisted-by: Claude
* Bound native recursion where the C stack cannot be measured
check_c_stack_overflow() answers no unconditionally under miri and on
musl, where the stack pointer is not read. Since 9c9905aff that check is
all with_recursion() does, so every guard placed on native recursion --
__call__ and __get__ dispatch among them -- was a no-op on those targets
and the nesting ran until the stack ran out.
with_recursion() now counts its own depth on those targets and refuses
past NATIVE_RECURSION_LIMIT_UNMEASURED. The count is separate from the
frame limit sys.setrecursionlimit() sets, and compiles away where the
stack pointer can be read.
Assisted-by: Claude
* Report the failure to allocate pbkdf2's key and Take.readinto's scratch
Both buffers are sized from an argument -- pbkdf2_hmac's dklen accepts up
to i32::MAX, and readinto's from the length of the destination -- and were
built with vec![0u8; n], which aborts the process on allocation failure.
new_zeroed_bytes() raises MemoryError instead.
Assisted-by: Claude
* Read the frozen-code tuple length as a signed length
The '(' branches in read_marshal_str_vec() and read_marshal_const_tuple()
took the length with read_u32() as usize, so a value with the top bit set
read as four billion items rather than as out of range. read_len() is what
every other length in this file goes through, and it reinterprets as i32.
Both readers serve deserialize_code(), which reads only the frozen modules
baked in at build time, so this changes no reachable behavior;
marshal.loads() already went through read_len().
Assisted-by: Claude
* Make the snippets from the fuzzer sweep assert what they check
builtin_str.py expanded a tab to 2**31-1 columns, allocating 2 GiB to
observe that the width is accepted; a string with no tab observes the same
acceptance without laying anything out.
stdlib_array.py caught the refusal of frombytes() on its own exported
buffer and passed silently when nothing was raised. stdlib_hashlib.py
used a bare `assert False` as its failure branch. Both now say so through
the same shapes the other snippets use.
stdlib_socket.py also accepts OverflowError from recv() with a size that
does not fit the platform's C int.
stdlib_threading_current_frames.py indexed the frame chain for "f123"
without first asserting it is there.
Assisted-by: Claude
* Ask for a marshal container's room instead of assuming it
A flagged tuple or list is published in the reference table before its
children are read, and the placeholder was built with vec![none; len].
The length is the input's to choose and read_len() lets it reach
i32::MAX, so marshal.loads(b"\xa8\xff\xff\xff\x7f") -- five bytes -- asks
for 17 GB of element slots and aborts the process where the allocator
cannot serve it. r_object() allocates the container up front too, but
PyTuple_New() reports what it cannot get.
The elements are now reserved with try_reserve_exact() and a refusal is
raised as MemoryError through the decoder's pending-error channel.
PyTuple::new_marshal_placeholder() held nothing but that allocation and
is gone; the caller builds the elements and uses new_ref().
Assisted-by: Claude
* Compare the blocking-buffer snippet against something
measure() asserted len(buf) == len(buf), which holds whatever the length
is; it now takes the length the caller expects. The pipe case compared
the drained total against the whole source, while an unbuffered write()
reports only what it transferred and a signal can cut that short; it now
compares against what write() returned.
Assisted-by: Claude
* Refuse array.frombytes() a source whose items are not bytes
frombytes() reads its argument as bytes, but accepted any contiguous
buffer, so array("i").frombytes(memoryview(array("d", [1.0]))) appended a
double's bytes read as ints instead of raising. array_array_frombytes_impl
requires an itemsize of 1; ArgBytesLike now reports the itemsize so the
same check can be made here.
The BufferError that a resize meets while the array is exported also names
the array rather than repeating bytearray's wording.
stdlib_array.py's frombytes-of-itself case used typecode "i", where the
new check answers before the resize guard is reached; it uses "b" so the
guard is what refuses, and asserts the wider case separately.
Assisted-by: Claude
* Tell apart the ways marshal data can be bad
A type byte no reader knows, a back reference that names nothing, and
TYPE_NULL all came out as a bare "bad marshal data" ValueError. r_object()
answers the first two with "bad marshal data (unknown type code)" and
"bad marshal data (invalid reference)", and read_object() answers the
third with a TypeError, "NULL object in marshal data for object", since
TYPE_NULL stands for no object rather than for a value.
MarshalError gains the three cases and deserialize_value() maps them.
The container-specific wording r_object() uses for a NULL read inside a
tuple or list is not reproduced; the exception type is.
Assisted-by: Claude
* Hash the collector's tables by address rather than by SipHash
A collection keys three sets and two maps by object address, and it visits
every tracked object and every edge between them, so the hashing is a
per-edge cost. Those tables used the default RandomState, whose SipHash
buys resistance against a caller choosing colliding keys -- and nothing
chooses these keys: they are addresses this process handed out into tables
that live and die inside one collection. A profile of gc.collect() over a
423k-object heap spent 45% of its samples in SipHash.
They now hash with a splitmix64 finalizer. The shifts matter: a table
picks its bucket from the low bits and an address arrives with those bits
zeroed by alignment, so a plain multiply leaves every object in a handful
of buckets and is slower than SipHash was.
The reachability walk also copied each object's referent vector out of the
map it was cached in, a second pass over every edge; it reads them in
place, and reference subtraction hands its vector to the map instead of
cloning it.
Measured over 423k live objects: 0.93s to 0.15s. Over 843k dead ones:
3.00s to 0.79s. extra_tests/snippets/stdlib_threading_gc_import.py, whose
collector thread calls gc.collect() in a loop, ran anywhere from 2.7s to
28s and now runs in 3.1-3.5s: a collection that takes longer leaves more
garbage for the next one to walk, so the cost fed back on itself.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* Keep the collection's candidates and their counts in one table
A collection built a set of candidates and, beside it, a map from the same
addresses to their reference counts. Both were probed for every edge in
the heap -- membership from the set, the count from the map -- so each
edge paid to hash the same address twice, and each candidate paid to be
inserted twice. The map alone answers both questions.
The candidates also keep a walkable order now, which the reference
subtraction pass needs since it writes the counts while reading the
candidates, and which the unreachable set is built from instead of a
set difference.
Over the 423k-object heap measured in the previous commit: 0.15s to
0.13s live, and 0.79s to 0.49s dead.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* gc: collect referents into one buffer instead of a vector per object
Step 3 allocated a `Vec` for every tracked object to hold its referents
and kept them all in a map until step 4 read them back. The referents now
go into a single growing buffer, with the map holding each object's range
into it.
Adds `PyObject::gc_extend_referent_ptrs`, which appends to a caller's
buffer; `gc_get_referent_ptrs` calls it with a fresh one.
Assisted-by: Claude
* memoryview and struct: match the checks and errors of the reference
memoryview:
- `cast()` accepted a source and destination that are both item types,
which reinterprets the items rather than re-dividing the bytes; one side
now has to be a byte format.
- A cast to `shape=()` returned without checking that the buffer holds
exactly the one item that shape describes.
- `hash()` hashes the bytes, so it now raises ValueError for a view whose
items are not bytes, rather than returning a hash that disagrees with the
value the view compares equal to.
- `tobytes()` takes the `order` argument, with 'F' walking a
multidimensional view down its columns; `BufferDescriptor` gained
`for_each_segment_fortran` for that walk.
struct:
- A value the format has no room for reported "argument out of range"
instead of naming the format and its range. The format character is now
passed to the packing functions to report it.
- `Struct.__new__` no longer reads the format; `__init__` does, so
`__init__` can be called again and a subclass can pass the format up.
Methods raise RuntimeError until it has run, and `Struct` is a base type.
Removes the expectedFailure from test_Struct_reinitialization and
test_struct_subclass_instantiation.
Assisted-by: Claude
Assisted-by: Codex:GPT-5
* io: decide the readinto path by file type, not by seekability
FileIO.readinto wrote straight into the caller's buffer, holding its write
borrow, when the fd was seekable; otherwise it read aside into scratch and
copied. Seekability stood in for "this read answers without waiting on a
peer", which a pipe on Windows breaks: lseek on one succeeds, so the pipe
took the borrow-holding path and every other thread touching that bytearray
waited for the peer.
host_io::reads_without_waiting answers it directly -- seekability elsewhere,
GetFileType() == FILE_TYPE_DISK on Windows.
The regression snippet times each operation separately, so a failure names
the one that waited; it asserts the transfer is still in flight before
checking the export; and the socket case fills the connection until it
refuses rather than assuming a size that outruns it, which SO_SNDBUF on an
already-connected pair does not settle.
Assisted-by: Claude
* str: count an empty needle in characters
str.count with an empty needle ran find_iter over the range's bytes, which
reports one position per encoded byte boundary rather than one per
character: '가나다'.count('') answered 10 instead of 4. Count the range's
code points instead; bytes.count keeps the byte-position answer.
Assisted-by: Claude
* str: take search bounds through the character index
find, rfind, index, rindex, count, startswith and endswith resolved their
start/stop bounds with AnyStr::get_chars, which walks the payload to both
bounds, and find reported its hit by counting the code points in front of
it -- so a sweep over a subject's own indices walked it once per call.
Resolve the bounds with StrData::char_range_to_bytes instead, which is the
converter the subscript and slice paths already use, and map the hit back
with Wtf8Index::char_index_at_byte, added here as the table's inverse: a
bracketed search over the groups, then at most an entry's worth of steps.
The payload alone does not say whether it is ASCII, so get_chars walked
there too; that path is now off it as well.
n=8000, sweeping the bound over the subject, best of 3, interleaved:
'가나다라'*n/4 'abcd'*n/4
find 18.00ms -> 0.15ms 3.48ms -> 0.14ms
startswith 16.75ms -> 0.12ms
count 22.78ms -> 4.02ms
count stays linear in the range it is given, as it is in CPython.
Assisted-by: Claude
* PyBytes.title should be ASCII-only.
* Use icu_casemap over unicode-casing for titles
`icu_casemap` is consistently maintained, official, and tracks the
latest Unicode versions. RustPython is also using other `icu4x` crates,
so using `icu_casemap` is more consistent.
As with islower and isupper, tracking the latest Unicode version is
important because character definitions shift over time which causes
discrepancies between RustPython and CPython.
This commit fixes title().
* Use icu_casemap for capitalize()
I dropped unicode-casing because it's cleaner to use icu4x for
everything. `icu4x` will also stay up to date whereas unicode-casing
will need to be periodically updated with new Unicode tables. Dropping
unicode-casing also removes some binary bloat due to the tables.
`capitalize()` mimics CPython behavior more closely now as well.
Notably, I implemented CPython's sigma edge case handler.
* Match CPython's title() exactly
This PR fixes a regression from my last islower/isupper patch.
Python's Bytes doesn't assume an encoding, so methods like islower
should only consider ASCII casing.
I updated islower/isupper for UTF-8 and WTF-8 to match CPython more
closely. The two functions now use the same properties as CPython and
now match CPython exactly.
I updated the unit tests to pass on Python 3.15. Unicode updates
sometimes cause properties to shift. I previously tested everything on
Python 3.14, but that lead to failures that I assumed were bugs but were
actually due to Unicode differences. For example, U+0295 is a lower case
letter in older Unicode versions but is NOT in newer versions.
One of the new tests is disabled on Python 3.14 for now because it will
fail in CI till CI is bumped to 3.15.
Rust and Python differ in which properties they use for alphanumeric,
numeric, et cetera. Both languages list which properties are used which
makes it easy to mimic Python's behavior in Rust.
My previous patch was a bit shortsighted because I filtered out
combining characters from is_alphanumeric. Using properties is exact and
also much cleaner. It also covers edge cases that my initial approach
missed.
Besides isalnum, I also fixed isnumeric and isdigit in the same way by
using properties.
* fix: Python-Rust combining char diff in isalnum
Related to: #7518
Rust and Python differ on alphanumeric characters. Rust follows the
Unicode standard closer than Python. This means that is_alphanumeric
(char function in Rust) is different from isalnum (Python). To fix the
discrepancy, RustPython needs to mimic Python by rejecting certain
characters. Some classes of combining characters count as alphanumeric
in Rust but not Python. Combining characters are accent marks
that are combined with other characters to create a single grapheme.
It's possible that this PR is not exhaustive. I fixed the combining
character issue BUT I don't know the full range of discrepancies.
* fix: Ignore combining characters in SRE
Closes: #7518
* fix: Handle char expansion in islower, isupper
Closes: #7526
`py_islower` and `py_isupper` need to handle expansions for letter
casing. Comparing chars directly can miss edge cases in certain
languages. Unfortunately, like the last PR, this allocates to handle
potential expansions.
I also had to add `icu_casemap` as a dependency.
RustPython is already using parts of icu4x so this doesn't add many
transitive dependencies.
* Ensure islower/isupper handles strs without chars
This fixes a regression mentioned by CodeRabbit. I also figured out how
to check a string's case without allocation using Unicode properties.
Thus, this commit removes `icu_casemap` again. `icu_casemap` and my old
solution is required for a robust case check, but it seems like the
current code is fine for Python.
`swapcase` used `to_ascii_lowercase` and uppercase to swap cases. This
is fine for ASCII, but code points may expand into multiple bytes which
leads to incorrect case swaps for some languages. The fix is to use
`to_lowercase` and `to_uppercase` instead.
Unfortunately, this leads to a realloc in `swapcase` when bytes are
expanded.
Part of #7526.
youknowdot