[ty] Infer typevar specializations for implicit generic protocols by dcreager · Pull Request #21902 · astral-sh/ruff

dcreager · 2025-12-10T18:22:13Z

We now infer specializations that involve generic protocols. This includes recursing into the methods of the protocol, matching up the signatures of the class's methods with the signatures of the protocol, and adding bindings for any typevars that appear in the protocol signatures.

This required several performance updates, which were pulled out and merged as separate PRs. There is still a performance and memory hit, but I think a reasonable one, given the new functionality that this opens up.

There are still some ecosystem false positives that relate to how this interacts with overload resolution, but I plan to tackle that in follow-on PRs.

astral-sh-bot · 2025-12-10T18:24:16Z

Typing conformance results improved 🎉

The percentage of diagnostics emitted that were expected errors increased from 83.14% to 83.49%. The percentage of expected errors that received a diagnostic held steady at 74.24%.

Summary

Metric	Old	New	Diff	Outcome
True Positives	804	804	+0
False Positives	163	159	-4	⏬ (✅)
False Negatives	279	279	+0
Total Diagnostics	967	963	-4	⏬
Precision	83.14%	83.49%	+0.35%	⏫ (✅)
Recall	74.24%	74.24%	+0.00%

False positives removed

Details

Location	Name	Message
generics_base_class.py:45:5	type-assertion-failure	Type `Iterator[int]` does not match asserted type `Unknown`
generics_basic.py:139:5	type-assertion-failure	Type `int` does not match asserted type `Unknown`
generics_basic.py:140:5	type-assertion-failure	Type `int` does not match asserted type `Unknown`
generics_basic.py:199:5	type-assertion-failure	Type `Iterator[Any]` does not match asserted type `Unknown`

codspeed-hq · 2025-12-16T00:58:36Z

Merging this PR will degrade performance by 19.23%

⚡ 1 improved benchmark
❌ 5 (👁 5) regressed benchmarks
✅ 48 untouched benchmarks

Performance Changes

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
👁	WallTime	`pandas`	73 s	77.8 s	-6.14%
👁	WallTime	`sympy`	52.4 s	55.3 s	-5.26%
👁	WallTime	`static_frame`	26.7 s	29.9 s	-10.81%
👁	WallTime	`colour_science`	104.3 s	129.1 s	-19.23%
👁	Simulation	`attrs`	435.7 ms	461.3 ms	-5.56%
⚡	Simulation	`DateType`	232.9 ms	210 ms	+10.88%

_{Comparing dcreager/genprop (b66cf8b) with main (8cfeae8)}

astral-sh-bot · 2025-12-16T01:49:18Z

`ruff-ecosystem` results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

Formatter (stable)

✅ ecosystem check detected no format changes.

Formatter (preview)

✅ ecosystem check detected no format changes.

astral-sh-bot · 2026-02-10T14:16:48Z

Memory usage report

Summary

Project	Old	New	Diff	Outcome
sphinx	270.10MB	270.83MB	+0.27% (743.08kB)	⏫
flake8	49.45MB	49.50MB	+0.10% (49.15kB)	⏫
trio	118.29MB	118.05MB	-0.20% (242.36kB)	⬇️
prefect	681.16MB	680.31MB	-0.12% (861.68kB)	⬇️

Significant changes

Click to expand detailed breakdown

sphinx

Name	Old	New	Diff	Outcome
`infer_expression_types_impl`	21.26MB	21.53MB	+1.31% (284.18kB)	⏫
`for_constraint_pair_inner`	56.36kB	182.46kB	+223.77% (126.11kB)	⏫
`solutions_inner`	21.50kB	103.55kB	+381.56% (82.05kB)	⏫
`CallableType`	1.20MB	1.12MB	-6.25% (76.64kB)	⏫
`for_constraint_inner`	32.88kB	102.57kB	+211.94% (69.69kB)	⏫
`InteriorNode`	27.93kB	86.33kB	+209.09% (58.40kB)	⏫
`StaticClassLiteral<'db>::try_mro_`	2.12MB	2.17MB	+2.17% (47.15kB)	⏫
`infer_definition_types`	23.34MB	23.39MB	+0.20% (47.00kB)	⏫
`ConstrainedTypeVar`	17.72kB	53.25kB	+200.53% (35.53kB)	⏫
`InteriorNode<'db>::or_::interned_arguments`	560.00B	30.78kB	+5528.57% (30.23kB)	⏫
`for_constraint_pair_inner::interned_arguments`	14.13kB	43.52kB	+207.96% (29.39kB)	⏫
`InteriorNode<'db>::or_`	476.00B	28.85kB	+6105.88% (28.38kB)	⏫
`Type<'db>::try_call_dunder_get_`	5.52MB	5.49MB	-0.46% (25.70kB)	⏫
`Specialization`	1.03MB	1.05MB	+1.87% (19.77kB)	⏫
`is_equivalent_to_object_inner`	105.09kB	122.50kB	+16.57% (17.41kB)	⏫
...			54 more

flake8

Name	Old	New	Diff	Outcome
`CallableType`	205.17kB	182.39kB	-11.10% (22.78kB)	⏫
`StaticClassLiteral<'db>::try_mro_`	333.77kB	344.66kB	+3.26% (10.89kB)	⏫
`solutions_inner`	2.85kB	12.46kB	+336.85% (9.61kB)	⏫
`for_constraint_pair_inner`	4.11kB	12.90kB	+213.68% (8.79kB)	⏫
`for_constraint_inner`	3.77kB	12.34kB	+227.02% (8.57kB)	⏫
`FunctionType`	435.38kB	441.31kB	+1.36% (5.94kB)	⏫
`InteriorNode`	3.45kB	9.24kB	+167.65% (5.79kB)	⏫
`is_equivalent_to_object_inner`	23.33kB	28.31kB	+21.35% (4.98kB)	⏫
`ConstrainedTypeVar`	2.16kB	6.66kB	+208.70% (4.50kB)	⏫
`infer_scope_types_impl`	1.09MB	1.08MB	-0.32% (3.59kB)	⏫
`Type<'db>::class_member_with_policy_`	577.16kB	573.62kB	-0.61% (3.54kB)	⏫
`Type<'db>::try_call_dunder_get_`	415.30kB	411.95kB	-0.81% (3.35kB)	⏫
`InteriorNode<'db>::or_::interned_arguments`	320.00B	3.52kB	+1025.00% (3.20kB)	⏫
`infer_deferred_types`	717.88kB	714.79kB	-0.43% (3.09kB)	⏫
`InteriorNode<'db>::or_`	272.00B	3.25kB	+1122.06% (2.98kB)	⏫
...			50 more

trio

Name	Old	New	Diff	Outcome
`infer_scope_types_impl`	5.56MB	5.45MB	-1.97% (112.37kB)	⬇️
`CallableType`	700.79kB	597.36kB	-14.76% (103.43kB)	⬇️
`FunctionType`	1.57MB	1.54MB	-2.11% (34.09kB)	⬇️
`FunctionType<'db>::signature_`	1.11MB	1.09MB	-2.26% (25.82kB)	⬇️
`for_constraint_inner`	36.11kB	60.23kB	+66.83% (24.13kB)	⬇️
`cached_protocol_interface`	153.93kB	133.39kB	-13.34% (20.53kB)	⬇️
`for_constraint_pair_inner`	40.04kB	59.20kB	+47.85% (19.16kB)	⬇️
`solutions_inner`	20.74kB	38.67kB	+86.48% (17.93kB)	⬇️
`InteriorNode`	25.70kB	43.16kB	+67.98% (17.47kB)	⬇️
`Type<'db>::apply_specialization_`	786.48kB	770.04kB	-2.09% (16.44kB)	⬇️
`infer_definition_types`	7.18MB	7.17MB	-0.22% (16.43kB)	⬇️
`infer_unpack_types`	163.69kB	150.60kB	-8.00% (13.09kB)	⬇️
`ProtocolInterface`	106.82kB	94.70kB	-11.35% (12.12kB)	⬇️
`ConstrainedTypeVar`	18.84kB	30.84kB	+63.68% (12.00kB)	⬇️
`BoundMethodType<'db>::into_callable_type_`	81.80kB	71.95kB	-12.03% (9.84kB)	⬇️
...			55 more

prefect

Name	Old	New	Diff	Outcome
`CallableType`	2.31MB	1.88MB	-18.67% (442.16kB)	⬇️
`FunctionType`	8.71MB	8.43MB	-3.21% (286.47kB)	⬇️
`for_constraint_pair_inner`	150.76kB	424.28kB	+181.42% (273.52kB)	⬇️
`FunctionType<'db>::signature_`	4.08MB	3.92MB	-3.96% (165.14kB)	⬇️
`cached_protocol_interface`	524.92kB	382.52kB	-27.13% (142.39kB)	⬇️
`infer_expression_types_impl`	51.14MB	51.25MB	+0.22% (113.27kB)	⬇️
`solutions_inner`	79.25kB	192.12kB	+142.42% (112.87kB)	⬇️
`Type<'db>::class_member_with_policy_`	16.91MB	16.80MB	-0.65% (111.73kB)	⬇️
`InteriorNode`	86.23kB	195.71kB	+126.97% (109.48kB)	⬇️
`for_constraint_inner`	111.91kB	217.38kB	+94.24% (105.47kB)	⬇️
`Type<'db>::try_call_dunder_get_`	11.25MB	11.15MB	-0.91% (105.18kB)	⬇️
`infer_scope_types_impl`	57.37MB	57.27MB	-0.18% (104.09kB)	⬇️
`Type<'db>::apply_specialization_`	3.79MB	3.70MB	-2.48% (96.25kB)	⬇️
`ProtocolInterface`	358.12kB	274.76kB	-23.28% (83.35kB)	⬇️
`Type<'db>::class_member_with_policy_::interned_arguments`	8.90MB	8.83MB	-0.81% (73.94kB)	⬇️
...			65 more

crates/ty_python_semantic/src/types.rs

AlexWaygood

Awesome work!! This looks very reasonable to me

scripts/conformance.py

scripts/uv.lock

crates/ty_python_semantic/resources/mdtest/generics/legacy/classes.md

crates/ty_python_semantic/resources/mdtest/generics/pep695/classes.md

crates/ty_python_semantic/src/types/constraints.rs

crates/ty_python_semantic/src/types/generics.rs

crates/ty_python_semantic/src/types/instance.rs

sharkdp

Very cool — thank you!

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

dcreager added the ty Multi-file analysis & type inference label Dec 10, 2025

dcreager force-pushed the dcreager/genprop branch from 6b69581 to 0bde415 Compare December 13, 2025 21:21

dcreager added the ecosystem-analyzer label Dec 13, 2025

dcreager force-pushed the dcreager/callable-return branch 2 times, most recently from 874dc7e to 8871fdd Compare December 14, 2025 00:45

dcreager force-pushed the dcreager/genprop branch from 0bde415 to fa1a940 Compare December 16, 2025 00:41

dcreager changed the base branch from dcreager/callable-return to main December 16, 2025 01:26

dcreager force-pushed the dcreager/genprop branch 2 times, most recently from 7145810 to 6fb49ec Compare December 16, 2025 17:34

dcreager added 11 commits January 5, 2026 13:41

use csa for instance checks

517566a

these are legit

4ff828d

add TODO for Never/Unknown

c8664f6

make these tests consistent

2fa8636

error message

b6ca2d9

add todos

8888c3c

fix test expectations and TODOs

6df88e8

check protocols nominally, too

be4e7e7

only error when there are typevars

83378f0

no duplicate errors anymore

9ca1207

don't overwrite source_order

acd1e6c

dcreager force-pushed the dcreager/genprop branch from 6fb49ec to b0280a2 Compare January 5, 2026 20:49

dcreager added 5 commits January 5, 2026 21:13

constrain with bounds/constraints as post-processing step

47840fd

prefer informative upper bound again

61aafff

clippy

2c95bef

materialize the bounds too

e39f465

paramspec args/kwargs don't have a bound

138bf79

dcreager force-pushed the dcreager/genprop branch from 21736f1 to 138bf79 Compare January 6, 2026 02:25

dcreager added 5 commits February 6, 2026 14:28

don't walk too deeply in cycle check

c7d0c8f

sympy too

8b1b2f0

suppress duplicate diagnostics from constraint-set solver

bcfc732

merge main

7ccd2df

clean up callable inference error handling

06f1a23

dcreager force-pushed the dcreager/genprop branch from 7dc401e to 06f1a23 Compare February 10, 2026 14:25

don't capture enclosing typevars

4668e5d

dcreager marked this pull request as ready for review February 10, 2026 16:26

dcreager requested review from AlexWaygood, carljm and sharkdp as code owners February 10, 2026 16:26

sharkdp reviewed Feb 10, 2026

View reviewed changes

crates/ty_python_semantic/src/types.rs Show resolved Hide resolved

AlexWaygood reviewed Feb 10, 2026

View reviewed changes

sharkdp approved these changes Feb 11, 2026

View reviewed changes

dcreager and others added 5 commits February 11, 2026 15:04

Apply suggestions from code review

e078ee2

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

0 union size for never

01b3c33

remove spurious lock file

1fe411b

add comment + issue link about false positives

c72c93e

perform nominal check first moar better

b66cf8b

dcreager force-pushed the dcreager/genprop branch from e9ab2d2 to b66cf8b Compare February 11, 2026 20:52

dcreager merged commit dc65d12 into main Feb 11, 2026
50 checks passed

dcreager deleted the dcreager/genprop branch February 11, 2026 21:09

Hugo-Polloli mentioned this pull request Feb 15, 2026

False-positive missing-argument when setting method from staticmethod without decorator astral-sh/ty#2724

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Typing conformance results improved 🎉

Summary

False positives removed

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Merging this PR will degrade performance by 19.23%

Performance Changes

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ruff-ecosystem results

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Memory usage report

Summary

Significant changes

sphinx

flake8

trio

prefect

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`ruff-ecosystem` results

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