e7f38fe74b
Summary -- This PR extends semantic syntax error detection to red-knot. The main changes here are: 1. Adding `SemanticSyntaxChecker` and `Vec<SemanticSyntaxError>` fields to the `SemanticIndexBuilder` 2. Calling `SemanticSyntaxChecker::visit_stmt` and `visit_expr` in the `SemanticIndexBuilder`'s `visit_stmt` and `visit_expr` methods 3. Implementing `SemanticSyntaxContext` for `SemanticIndexBuilder` 4. Adding new mdtests to test the context implementation and show diagnostics (3) is definitely the trickiest and required (I think) a minor addition to the `SemanticIndexBuilder`. I tried to look around for existing code performing the necessary checks, but I definitely could have missed something or misused the existing code even when I found it. There's still one TODO around `global` statement handling. I don't think there's an existing way to look this up, but I'm happy to work on that here or in a separate PR. This currently only affects detection of one error (`LoadBeforeGlobalDeclaration` or [PLE0118](https://docs.astral.sh/ruff/rules/load-before-global-declaration/) in ruff), so it's not too big of a problem even if we leave the TODO. Test Plan -- New mdtests, as well as new errors for existing mdtests --------- Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
3.1 KiB
3.1 KiB
Comprehensions
Basic comprehensions
class IntIterator:
def __next__(self) -> int:
return 42
class IntIterable:
def __iter__(self) -> IntIterator:
return IntIterator()
# revealed: int
[reveal_type(x) for x in IntIterable()]
class IteratorOfIterables:
def __next__(self) -> IntIterable:
return IntIterable()
class IterableOfIterables:
def __iter__(self) -> IteratorOfIterables:
return IteratorOfIterables()
# revealed: tuple[int, IntIterable]
[reveal_type((x, y)) for y in IterableOfIterables() for x in y]
# revealed: int
{reveal_type(x): 0 for x in IntIterable()}
# revealed: int
{0: reveal_type(x) for x in IntIterable()}
Nested comprehension
class IntIterator:
def __next__(self) -> int:
return 42
class IntIterable:
def __iter__(self) -> IntIterator:
return IntIterator()
# revealed: tuple[int, int]
[[reveal_type((x, y)) for x in IntIterable()] for y in IntIterable()]
Comprehension referencing outer comprehension
class IntIterator:
def __next__(self) -> int:
return 42
class IntIterable:
def __iter__(self) -> IntIterator:
return IntIterator()
class IteratorOfIterables:
def __next__(self) -> IntIterable:
return IntIterable()
class IterableOfIterables:
def __iter__(self) -> IteratorOfIterables:
return IteratorOfIterables()
# revealed: tuple[int, IntIterable]
[[reveal_type((x, y)) for x in y] for y in IterableOfIterables()]
Comprehension with unbound iterable
Iterating over an unbound iterable yields Unknown:
# error: [unresolved-reference] "Name `x` used when not defined"
# revealed: Unknown
[reveal_type(z) for z in x]
class IntIterator:
def __next__(self) -> int:
return 42
class IntIterable:
def __iter__(self) -> IntIterator:
return IntIterator()
# error: [not-iterable] "Object of type `int` is not iterable"
# revealed: tuple[int, Unknown]
[reveal_type((x, z)) for x in IntIterable() for z in x]
Starred expressions
Starred expressions must be iterable
class NotIterable: ...
class Iterator:
def __next__(self) -> int:
return 42
class Iterable:
def __iter__(self) -> Iterator:
return Iterator()
# This is fine:
x = [*Iterable()]
# error: [not-iterable] "Object of type `NotIterable` is not iterable"
y = [*NotIterable()]
Async comprehensions
Basic
class AsyncIterator:
async def __anext__(self) -> int:
return 42
class AsyncIterable:
def __aiter__(self) -> AsyncIterator:
return AsyncIterator()
async def _():
# revealed: @Todo(async iterables/iterators)
[reveal_type(x) async for x in AsyncIterable()]
Invalid async comprehension
This tests that we understand that async comprehensions do not work according to the synchronous
iteration protocol
class Iterator:
def __next__(self) -> int:
return 42
class Iterable:
def __iter__(self) -> Iterator:
return Iterator()
async def _():
# revealed: @Todo(async iterables/iterators)
[reveal_type(x) async for x in Iterable()]