ruff/crates/red_knot_python_semantic
Carl Meyer 114abc7cfb
[red-knot] support empty TypeInference with fallback type (#16510)
This is split out of https://github.com/astral-sh/ruff/pull/14029, to
reduce the size of that PR, and to validate that this "fallback type"
support in `TypeInference` doesn't come with a performance cost. It also
improves the reliability and debuggability of our current (temporary)
cycle handling.

In order to recover from a cycle, we have to be able to construct a
"default" `TypeInference` where all expressions and definitions have
some "default" type. In our current cycle handling, this "default" type
is just unknown or a todo type. With fixpoint iteration, the "default"
type will be `Type::Never`, which is the "bottom" type that fixpoint
iteration starts from.

Since it would be costly (both in space and time) to actually enumerate
all expressions and definitions in a scope, just to insert the same
default type for all of them, instead we add an optional "missing type"
fallback to `TypeInference`, which (if set) is the fallback type for any
expression or definition which doesn't have an explicit type set.

With this change, cycles can no longer result in the dreaded "Missing
key" errors looking up the type of some expression.
2025-03-05 09:12:27 -08:00
..
resources [red-knot] Add rule invalid-type-checking-constant (#16501) 2025-03-04 19:49:34 +00:00
src [red-knot] support empty TypeInference with fallback type (#16510) 2025-03-05 09:12:27 -08:00
tests red_knot_test: add support for diagnostic snapshotting 2025-02-05 13:02:54 -05:00
build.rs Modernize build scripts (#13837) 2024-10-20 22:35:35 +01:00
Cargo.toml [red-knot] Add a test to ensure that KnownClass::try_from_file_and_name() is kept up to date (#16326) 2025-02-24 12:14:20 +00:00
mdtest.py [red-knot] Fix possible TOCTOU mistake in mdtest runner (#15673) 2025-01-22 15:24:25 +00:00
mdtest.py.lock [red-knot] Markdown test runner (#15632) 2025-01-21 14:06:35 +01:00