This updates _PyErr_ChainStackItem() to use _PyErr_SetObject()
instead of _PyErr_ChainExceptions(). This prevents a hang in
certain circumstances because _PyErr_SetObject() performs checks
to prevent cycles in the exception context chain while
_PyErr_ChainExceptions() doesn't.
When an asyncio.Task is cancelled, the exception traceback now
starts with where the task was first interrupted. Previously,
the traceback only had "depth one."
Clarify the zip built-in docstring.
This puts much simpler text up front along with an example.
As it was, the zip built-in docstring was technically correct. But too
technical for the reader who shouldn't _need_ to know about `__next__` and
`StopIteration` as most people do not need to understand the internal
implementation details of the iterator protocol in their daily life.
This is a documentation only change, intended to be backported to 3.8; it is
only tangentially related to PEP-618 which might offer new behavior options
in the future.
Wording based a bit more on enumerate per Brandt's suggestion.
This gets rid of the legacy wording paragraph which seems too tied to
implementation details of the iterator protocol which isn't relevant here.
Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>
This fixes both the traceback.py module and the C code for formatting syntax errors (in Python/pythonrun.c). They now both consistently do the following:
- Suppress caret if it points left of text
- Allow caret pointing just past end of line
- If caret points past end of line, clip to *just* past end of line
The syntax error formatting code in traceback.py was mostly rewritten; small, subtle changes were applied to the C code in pythonrun.c.
There's still a difference when the text contains embedded newlines. Neither handles these very well, and I don't think the case occurs in practice.
Automerge-Triggered-By: @gvanrossum
_Py_hashtable_get_entry_ptr() avoids comparing the entry hash:
compare directly keys.
Move _Py_hashtable_get_entry_ptr() just after
_Py_hashtable_get_entry_generic().
_Py_hashtable_t values become regular "void *" pointers.
* Add _Py_hashtable_entry_t.data member
* Remove _Py_hashtable_t.data_size member
* Remove _Py_hashtable_t.get_func member. It is no longer needed
to specialize _Py_hashtable_get() for a specific value size, since
all entries now have the same size (void*).
* Remove the following macros:
* _Py_HASHTABLE_GET()
* _Py_HASHTABLE_SET()
* _Py_HASHTABLE_SET_NODATA()
* _Py_HASHTABLE_POP()
* Rename _Py_hashtable_pop() to _Py_hashtable_steal()
* _Py_hashtable_foreach() callback now gets key and value rather than
entry.
* Remove _Py_hashtable_value_destroy_func type. value_destroy_func
callback now only has a single parameter: data (void*).
Rewrite _tracemalloc to store "trace_t*" rather than directly
"trace_t" in traces hash tables. Traces are now allocated on the heap
memory, outside the hash table.
Add tracemalloc_copy_traces() and tracemalloc_copy_domains() helper
functions.
Remove _Py_hashtable_copy() function since there is no API to copy a
key or a value.
Remove also _Py_hashtable_delete() function which was commented.
Rewrite _Py_hashtable_t type to always store the key as
a "const void *" pointer. Add an explicit "key" member to
_Py_hashtable_entry_t.
Remove _Py_hashtable_t.key_size member.
hash and compare functions drop their hash table parameter, and their
'key' parameter type becomes "const void *".
Add a new _Py_HashPointerRaw() function which avoids replacing -1
with -2 to micro-optimize hash table using pointer keys: using
_Py_hashtable_hash_ptr() hash function.
Optimize _Py_hashtable_get() and _Py_hashtable_get_entry() for
pointer keys:
* key_size == sizeof(void*)
* hash_func == _Py_hashtable_hash_ptr
* compare_func == _Py_hashtable_compare_direct
Changes:
* Add get_func and get_entry_func members to _Py_hashtable_t
* Convert _Py_hashtable_get() and _Py_hashtable_get_entry() functions
to static nline functions.
* Add specialized get and get entry for pointer keys.
_Py_hashtable_new() now uses PyMem_Malloc/PyMem_Free allocator by
default, rather than PyMem_RawMalloc/PyMem_RawFree.
PyMem_Malloc is faster than PyMem_RawMalloc for memory blocks smaller
than or equal to 512 bytes.
