[jseop-lim]

Description

Fixes #1249

The tp_new signature of _collections._tuplegetter declared index and doc with no minimum and no positional-only count, so a call with fewer than two arguments built a getter for index 0, and both arguments could be passed by keyword. CPython's tuplegetter_new rejects keywords and requires exactly two positional arguments (_collectionsmodule.c.h#L607-L613).

AS-IS

>>> from collections import _tuplegetter
>>> _tuplegetter(0)
<_collections._tuplegetter object at 0x...>
>>> _tuplegetter()
<_collections._tuplegetter object at 0x...>
>>> _tuplegetter(0, doc=None)
<_collections._tuplegetter object at 0x...>

TO-BE

>>> _tuplegetter(0)
TypeError: _tuplegetter() missing 1 required positional argument: 'doc'
>>> _tuplegetter()
TypeError: _tuplegetter() missing 2 required positional arguments: 'index' and 'doc'
>>> _tuplegetter(0, doc=None)
TypeError: _tuplegetter() got some positional-only arguments passed as keyword arguments: 'doc'

(matching CPython's exception type; the messages are GraalPy's usual argument errors)

Changes

• Add minNumOfPositionalArgs = 3, numOfPositionalOnlyArgs = 3 to the @SlotSignature of TupleGetterBuiltins.TupleGetterNode.
• Add test_tuplegetter_arguments to tests/test_collections.py.

Testing

mx python-jvm on darwin-aarch64, then tests/test_collections.py (2 passed). The new test fails on the unpatched build. _tuplegetter(0, None) still creates the getter, _tuplegetter(1, 'd').__get__((10, 20)) returns 20, and namedtuple field access and field docs work as before.