## Summary
This changeset adds support for precise type-inference and
boundness-handling of definitions inside control-flow branches with
statically-known conditions, i.e. test-expressions whose truthiness we
can unambiguously infer as *always false* or *always true*.
This branch also includes:
- `sys.platform` support
- statically-known branches handling for Boolean expressions and while
loops
- new `target-version` requirements in some Markdown tests which were
now required due to the understanding of `sys.version_info` branches.
closes#12700closes#15034
## Performance
### `tomllib`, -7%, needs to resolve one additional module (sys)
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| `./red_knot_main --project /home/shark/tomllib` | 22.2 ± 1.3 | 19.1 |
25.6 | 1.00 |
| `./red_knot_feature --project /home/shark/tomllib` | 23.8 ± 1.6 | 20.8
| 28.6 | 1.07 ± 0.09 |
### `black`, -6%
| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| `./red_knot_main --project /home/shark/black` | 129.3 ± 5.1 | 119.0 |
137.8 | 1.00 |
| `./red_knot_feature --project /home/shark/black` | 136.5 ± 6.8 | 123.8
| 147.5 | 1.06 ± 0.07 |
## Test Plan
- New Markdown tests for the main feature in
`statically-known-branches.md`
- New Markdown tests for `sys.platform`
- Adapted tests for `EllipsisType`, `Never`, etc
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## Summary
- Remove `Type::Unbound`
- Handle (potential) unboundness as a concept orthogonal to the type
system (see new `Symbol` type)
- Improve existing and add new diagnostics related to (potential)
unboundness
closes#13671
## Test Plan
- Update existing markdown-based tests
- Add new tests for added/modified functionality
## Summary
As python uses short-circuiting boolean operations in runtime, we should
mimic that logic in redknot as well.
For example, we should detect that in the following code `x` might be
undefined inside the block:
```py
if flag or (x := 1):
print(x)
```
## Test Plan
Added mdtest suit for boolean expressions.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
