Use sequence repetition for ctypes array types by 1ndahous3 · Pull Request #9185 · RustPython/RustPython

1ndahous3 · 2026-10-18T08:53:56Z

Found while importing Scapy 2.8.0 on Windows, where an array type is declared as 8 * ctypes.c_char.

Summary

Support both multiplication orders for all ctypes type families, including unions and function pointers.
Use the shared sequence-repeat slot to accept integer-like lengths and preserve reflected-operator dispatch.

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Summary by CodeRabbit

New Features
- ctypes types now support sequence repetition in either operand order, including scalar, array, pointer, structure, union, and function-pointer types.
- Repetition accepts integer-like values, including objects that provide an integer index. A right-hand operand can also customize the operation through its reverse multiplication behavior.
- Invalid and out-of-range lengths raise ValueError, TypeError, or OverflowError, as appropriate.

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chatgpt-codex-connector · 2026-10-18T08:54:09Z

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-18T13:50:37.609603Z	`e1dbdce`	New commits

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coderabbitai · 2026-10-18T08:54:33Z

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extra_tests/snippets/stdlib_ctypes.py

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📝 Walkthrough

ctypes metaclasses now use sequence protocols for type repetition. Array-type creation uses a shared helper that validates operands and lengths. Tests cover repetition across ctypes types, index-based lengths, and reflected multiplication.

Changes: ctypes Sequence Repetition

Layer / File(s)	Summary
Shared array repetition `crates/vm/src/stdlib/_ctypes/array.rs`	Array types use sequence methods for repetition. The shared helper rejects negative lengths, non-type operands, and lengths above the `isize`-based limit with the corresponding errors, then calls the cached array-type factory.
Sequence protocol across ctypes metaclasses `crates/vm/src/stdlib/_ctypes/function.rs`, `crates/vm/src/stdlib/_ctypes/pointer.rs`, `crates/vm/src/stdlib/_ctypes/simple.rs`, `crates/vm/src/stdlib/_ctypes/structure.rs`, `crates/vm/src/stdlib/_ctypes/union.rs`, `extra_tests/snippets/stdlib_ctypes.py`	Function-pointer, pointer, simple, structure, and union metaclasses expose the shared sequence methods instead of numeric multiplication methods. Simple-type repetition delegates to the shared array helper. Tests cover both operand orders, index-based lengths, and reflected multiplication.

Priority: ➖ Normal

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix

Suggested reviewers: youknowone

Merge Risk: ⚪ Minimal · up to e1dbd

This change enables sequence repetition across ctypes type families while preserving index-like lengths and reflected multiplication. The inspected paths show no concrete merge-blocking regression; it is mergeable subject to normal checks.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 53.33% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 30 functions across 7 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Description Check		Check skipped - CodeRabbit’s high-level summary is enabled.
Title check		The title clearly and concisely describes the main change: using sequence repetition for ctypes array types. It matches the pull request objectives and changeset.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

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codspeed · 2026-10-18T14:42:46Z

Merging this PR will improve performance by 15.86%

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Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
✅ 61 untouched benchmarks
⏩ 4 skipped benchmarks¹

Performance Changes

	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	`rustpython[frozenset.py]`	414.1 µs	357.5 µs	+15.86%

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Curious why performance improved? Comment @codspeedbot explain why performance improved on this PR, or directly use the CodSpeed MCP with your agent.

_{Comparing 1ndahous3:ctypes_array_reflected (e1dbdce) with main (6e064e5)²}

4 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩
No successful run was found on main (e411f91) during the generation of this report, so 6e064e5 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

Use sequence repetition for ctypes array types

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chatgpt-codex-connector Bot reviewed Oct 18, 2026

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Comment thread extra_tests/snippets/stdlib_ctypes.py

youknowone approved these changes Oct 18, 2026

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Merge branch 'main' into ctypes_array_reflected

9d9740e

youknowone enabled auto-merge (squash) October 18, 2026 13:36

Merge branch 'main' into ctypes_array_reflected

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Comment thread crates/vm/src/stdlib/_ctypes/union.rs

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Use sequence repetition for ctypes array types - #9185

Use sequence repetition for ctypes array types#9185
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Merging this PR will improve performance by 15.86%

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