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[ty] Support variable-length tuples in unpacking assignments (#18948)
This PR updates our unpacking assignment logic to use the new tuple machinery. As a result, we can now unpack variable-length tuples correctly. As part of this, the `TupleSpec` classes have been renamed to `Tuple`, and can now contain any element (Rust) type, not just `Type<'db>`. The unpacker uses a tuple of `UnionBuilder`s to maintain the types that will be assigned to each target, as we iterate through potentially many union elements on the rhs. We also add a new consuming iterator for tuples, and update the `all_elements` methods to wrap the result in an enum (similar to `itertools::Position`) letting you know which part of the tuple each element appears in. I also added a new `UnionBuilder::try_build`, which lets you specify a different fallback type if the union contains no elements.
This commit is contained in:
Douglas Creager
GitHub
parent
a50a993b9c
commit
c60e590b4c
11 changed files with 779 additions and 423 deletions
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@ -24,7 +24,7 @@ error[invalid-assignment]: Not enough values to unpack
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1 | [a, *b, c, d] = (1, 2) # error: [invalid-assignment]
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| ^^^^^^^^^^^^^ ------ Got 2
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| |
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| Expected 3 or more
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| Expected at least 3
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info: rule `invalid-assignment` is enabled by default
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@ -106,7 +106,7 @@ reveal_type(d) # revealed: Literal[5]
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### Starred expression (1)
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```py
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# error: [invalid-assignment] "Not enough values to unpack: Expected 3 or more"
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# error: [invalid-assignment] "Not enough values to unpack: Expected at least 3"
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[a, *b, c, d] = (1, 2)
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reveal_type(a) # revealed: Unknown
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reveal_type(b) # revealed: list[Unknown]
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@ -119,7 +119,7 @@ reveal_type(d) # revealed: Unknown
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```py
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[a, *b, c] = (1, 2)
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reveal_type(a) # revealed: Literal[1]
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reveal_type(b) # revealed: list[Unknown]
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reveal_type(b) # revealed: list[Never]
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reveal_type(c) # revealed: Literal[2]
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```
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@ -154,7 +154,7 @@ reveal_type(c) # revealed: list[Literal[3, 4]]
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### Starred expression (6)
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```py
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# error: [invalid-assignment] "Not enough values to unpack: Expected 5 or more"
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# error: [invalid-assignment] "Not enough values to unpack: Expected at least 5"
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(a, b, c, *d, e, f) = (1,)
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reveal_type(a) # revealed: Unknown
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reveal_type(b) # revealed: Unknown
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@ -258,6 +258,155 @@ def _(value: list[int]):
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reveal_type(c) # revealed: int
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```
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## Homogeneous tuples
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### Simple unpacking
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```py
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def _(value: tuple[int, ...]):
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a, b = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: int
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```
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### Nested unpacking
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```py
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def _(value: tuple[tuple[int, ...], ...]):
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a, (b, c) = value
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reveal_type(a) # revealed: tuple[int, ...]
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reveal_type(b) # revealed: int
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reveal_type(c) # revealed: int
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```
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### Invalid nested unpacking
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```py
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def _(value: tuple[int, ...]):
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# error: [not-iterable] "Object of type `int` is not iterable"
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a, (b, c) = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: Unknown
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reveal_type(c) # revealed: Unknown
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```
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### Starred expression
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```py
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def _(value: tuple[int, ...]):
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a, *b, c = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: list[int]
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reveal_type(c) # revealed: int
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```
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## Mixed tuples
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```toml
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[environment]
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python-version = "3.11"
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```
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### Simple unpacking (1)
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```py
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def _(value: tuple[int, *tuple[str, ...]]):
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a, b = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: str
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```
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### Simple unpacking (2)
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```py
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def _(value: tuple[int, int, *tuple[str, ...]]):
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a, b = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: int
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```
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### Simple unpacking (3)
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```py
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def _(value: tuple[int, *tuple[str, ...], int]):
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a, b, c = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: str
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reveal_type(c) # revealed: int
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```
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### Invalid unpacked
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```py
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def _(value: tuple[int, int, int, *tuple[str, ...]]):
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# error: [invalid-assignment] "Too many values to unpack: Expected 2"
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a, b = value
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reveal_type(a) # revealed: Unknown
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reveal_type(b) # revealed: Unknown
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```
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### Nested unpacking
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```py
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def _(value: tuple[str, *tuple[tuple[int, ...], ...]]):
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a, (b, c) = value
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reveal_type(a) # revealed: str
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reveal_type(b) # revealed: int
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reveal_type(c) # revealed: int
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```
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### Invalid nested unpacking
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```py
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def _(value: tuple[str, *tuple[int, ...]]):
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# error: [not-iterable] "Object of type `int` is not iterable"
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a, (b, c) = value
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reveal_type(a) # revealed: str
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reveal_type(b) # revealed: Unknown
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reveal_type(c) # revealed: Unknown
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```
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### Starred expression (1)
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```py
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def _(value: tuple[int, *tuple[str, ...]]):
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a, *b, c = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: list[str]
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reveal_type(c) # revealed: str
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```
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### Starred expression (2)
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```py
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def _(value: tuple[int, *tuple[str, ...], int]):
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a, *b, c = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: list[str]
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reveal_type(c) # revealed: int
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```
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### Starred expression (3)
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```py
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def _(value: tuple[int, *tuple[str, ...], int]):
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a, *b, c, d = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: list[str]
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reveal_type(c) # revealed: str
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reveal_type(d) # revealed: int
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```
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### Starred expression (4)
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```py
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def _(value: tuple[int, int, *tuple[str, ...], int]):
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a, *b, c = value
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reveal_type(a) # revealed: int
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reveal_type(b) # revealed: list[int | str]
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reveal_type(c) # revealed: int
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```
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## String
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### Simple unpacking
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@ -290,7 +439,7 @@ reveal_type(b) # revealed: Unknown
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### Starred expression (1)
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```py
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# error: [invalid-assignment] "Not enough values to unpack: Expected 3 or more"
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# error: [invalid-assignment] "Not enough values to unpack: Expected at least 3"
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(a, *b, c, d) = "ab"
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reveal_type(a) # revealed: Unknown
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reveal_type(b) # revealed: list[Unknown]
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@ -299,7 +448,7 @@ reveal_type(d) # revealed: Unknown
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```
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```py
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# error: [invalid-assignment] "Not enough values to unpack: Expected 3 or more"
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# error: [invalid-assignment] "Not enough values to unpack: Expected at least 3"
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(a, b, *c, d) = "a"
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reveal_type(a) # revealed: Unknown
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reveal_type(b) # revealed: Unknown
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@ -312,7 +461,7 @@ reveal_type(d) # revealed: Unknown
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```py
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(a, *b, c) = "ab"
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reveal_type(a) # revealed: LiteralString
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reveal_type(b) # revealed: list[Unknown]
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reveal_type(b) # revealed: list[Never]
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reveal_type(c) # revealed: LiteralString
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```
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@ -726,7 +726,7 @@ impl<'db> Type<'db> {
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.map(|ty| ty.materialize(db, variance.flip())),
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)
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.build(),
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Type::Tuple(tuple_type) => Type::tuple(db, tuple_type.materialize(db, variance)),
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Type::Tuple(tuple_type) => Type::tuple(tuple_type.materialize(db, variance)),
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Type::TypeVar(type_var) => Type::TypeVar(type_var.materialize(db, variance)),
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Type::TypeIs(type_is) => {
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type_is.with_type(db, type_is.return_type(db).materialize(db, variance))
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@ -1141,7 +1141,7 @@ impl<'db> Type<'db> {
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match self {
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Type::Union(union) => Type::Union(union.normalized(db)),
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Type::Intersection(intersection) => Type::Intersection(intersection.normalized(db)),
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Type::Tuple(tuple) => Type::tuple(db, tuple.normalized(db)),
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Type::Tuple(tuple) => Type::tuple(tuple.normalized(db)),
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Type::Callable(callable) => Type::Callable(callable.normalized(db)),
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Type::ProtocolInstance(protocol) => protocol.normalized(db),
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Type::NominalInstance(instance) => Type::NominalInstance(instance.normalized(db)),
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@ -3458,7 +3458,7 @@ impl<'db> Type<'db> {
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Type::BooleanLiteral(bool) => Truthiness::from(*bool),
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Type::StringLiteral(str) => Truthiness::from(!str.value(db).is_empty()),
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Type::BytesLiteral(bytes) => Truthiness::from(!bytes.value(db).is_empty()),
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Type::Tuple(tuple) => match tuple.tuple(db).size_hint() {
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Type::Tuple(tuple) => match tuple.tuple(db).len().size_hint() {
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// The tuple type is AlwaysFalse if it contains only the empty tuple
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(_, Some(0)) => Truthiness::AlwaysFalse,
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// The tuple type is AlwaysTrue if its inhabitants must always have length >=1
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@ -4312,7 +4312,7 @@ impl<'db> Type<'db> {
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let mut parameter =
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Parameter::positional_only(Some(Name::new_static("iterable")))
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.with_annotated_type(instantiated);
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if matches!(spec.size_hint().1, Some(0)) {
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if matches!(spec.len().maximum(), Some(0)) {
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parameter = parameter.with_default_type(TupleType::empty(db));
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}
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Parameters::new([parameter])
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@ -5350,7 +5350,7 @@ impl<'db> Type<'db> {
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}
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builder.build()
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}
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Type::Tuple(tuple) => Type::Tuple(tuple.apply_type_mapping(db, type_mapping)),
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Type::Tuple(tuple) => Type::tuple(tuple.apply_type_mapping(db, type_mapping)),
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Type::TypeIs(type_is) => type_is.with_type(db, type_is.return_type(db).apply_type_mapping(db, type_mapping)),
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@ -444,6 +444,10 @@ impl<'db> UnionBuilder<'db> {
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}
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pub(crate) fn build(self) -> Type<'db> {
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self.try_build().unwrap_or(Type::Never)
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}
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pub(crate) fn try_build(self) -> Option<Type<'db>> {
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let mut types = vec![];
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for element in self.elements {
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match element {
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@ -460,9 +464,12 @@ impl<'db> UnionBuilder<'db> {
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}
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}
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match types.len() {
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0 => Type::Never,
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1 => types[0],
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_ => Type::Union(UnionType::new(self.db, types.into_boxed_slice())),
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0 => None,
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1 => Some(types[0]),
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_ => Some(Type::Union(UnionType::new(
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self.db,
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types.into_boxed_slice(),
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))),
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}
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}
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}
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@ -221,10 +221,10 @@ fn expand_type<'db>(db: &'db dyn Db, ty: Type<'db>) -> Option<Vec<Type<'db>>> {
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let expanded = tuple
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.all_elements()
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.map(|element| {
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if let Some(expanded) = expand_type(db, element) {
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if let Some(expanded) = expand_type(db, *element) {
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Either::Left(expanded.into_iter())
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} else {
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Either::Right(std::iter::once(element))
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Either::Right(std::iter::once(*element))
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}
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})
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.multi_cartesian_product()
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@ -286,9 +286,13 @@ impl<'db> Specialization<'db> {
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return tuple;
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}
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if let [element_type] = self.types(db) {
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return TupleType::new(db, TupleSpec::homogeneous(*element_type)).tuple(db);
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if let Some(tuple) = TupleType::new(db, TupleSpec::homogeneous(*element_type)) {
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return tuple.tuple(db);
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}
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}
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TupleType::new(db, TupleSpec::homogeneous(Type::unknown())).tuple(db)
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TupleType::new(db, TupleSpec::homogeneous(Type::unknown()))
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.expect("tuple[Unknown, ...] should never contain Never")
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.tuple(db)
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}
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/// Returns the type that a typevar is mapped to, or None if the typevar isn't part of this
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@ -330,7 +334,7 @@ impl<'db> Specialization<'db> {
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.collect();
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let tuple_inner = self
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.tuple_inner(db)
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.map(|tuple| tuple.apply_type_mapping(db, type_mapping));
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.and_then(|tuple| tuple.apply_type_mapping(db, type_mapping));
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Specialization::new(db, self.generic_context(db), types, tuple_inner)
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}
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@ -374,7 +378,7 @@ impl<'db> Specialization<'db> {
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pub(crate) fn normalized(self, db: &'db dyn Db) -> Self {
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let types: Box<[_]> = self.types(db).iter().map(|ty| ty.normalized(db)).collect();
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let tuple_inner = self.tuple_inner(db).map(|tuple| tuple.normalized(db));
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let tuple_inner = self.tuple_inner(db).and_then(|tuple| tuple.normalized(db));
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Self::new(db, self.generic_context(db), types, tuple_inner)
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}
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@ -394,7 +398,7 @@ impl<'db> Specialization<'db> {
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vartype.materialize(db, variance)
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})
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.collect();
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let tuple_inner = self.tuple_inner(db).map(|tuple| {
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let tuple_inner = self.tuple_inner(db).and_then(|tuple| {
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// Tuples are immutable, so tuple element types are always in covariant position.
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tuple.materialize(db, variance)
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});
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@ -637,7 +641,7 @@ impl<'db> SpecializationBuilder<'db> {
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(TupleSpec::Fixed(formal_tuple), TupleSpec::Fixed(actual_tuple)) => {
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if formal_tuple.len() == actual_tuple.len() {
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for (formal_element, actual_element) in formal_tuple.elements().zip(actual_tuple.elements()) {
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self.infer(formal_element, actual_element)?;
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self.infer(*formal_element, *actual_element)?;
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}
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}
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}
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@ -2835,7 +2835,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
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// it will actually be the type of the generic parameters to `BaseExceptionGroup` or `ExceptionGroup`.
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let symbol_ty = if let Type::Tuple(tuple) = node_ty {
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let mut builder = UnionBuilder::new(self.db());
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for element in tuple.tuple(self.db()).all_elements() {
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for element in tuple.tuple(self.db()).all_elements().copied() {
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builder = builder.add(
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if element.is_assignable_to(self.db(), type_base_exception) {
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element.to_instance(self.db()).expect(
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@ -3701,7 +3701,9 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
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ast::Expr::List(ast::ExprList { elts, .. })
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| ast::Expr::Tuple(ast::ExprTuple { elts, .. }) => {
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let mut assigned_tys = match assigned_ty {
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Some(Type::Tuple(tuple)) => Either::Left(tuple.tuple(self.db()).all_elements()),
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Some(Type::Tuple(tuple)) => {
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Either::Left(tuple.tuple(self.db()).all_elements().copied())
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}
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Some(_) | None => Either::Right(std::iter::empty()),
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};
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@ -6485,13 +6487,12 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
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op,
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),
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(Type::Tuple(lhs), Type::Tuple(rhs), ast::Operator::Add) => Some(Type::tuple(
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self.db(),
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TupleType::new(
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(Type::Tuple(lhs), Type::Tuple(rhs), ast::Operator::Add) => {
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Some(Type::tuple(TupleType::new(
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self.db(),
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lhs.tuple(self.db()).concat(self.db(), rhs.tuple(self.db())),
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),
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)),
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)))
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}
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// We've handled all of the special cases that we support for literals, so we need to
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// fall back on looking for dunder methods on one of the operand types.
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@ -6948,14 +6949,14 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
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// tuples.
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//
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// Ref: https://github.com/astral-sh/ruff/pull/18251#discussion_r2115909311
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let (minimum_length, _) = tuple.tuple(self.db()).size_hint();
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let (minimum_length, _) = tuple.tuple(self.db()).len().size_hint();
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if minimum_length > 1 << 12 {
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return None;
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}
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let mut definitely_true = false;
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let mut definitely_false = true;
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for element in tuple.tuple(self.db()).all_elements() {
|
||||
for element in tuple.tuple(self.db()).all_elements().copied() {
|
||||
if element.is_string_literal() {
|
||||
if literal == element {
|
||||
definitely_true = true;
|
||||
|
|
@ -7238,7 +7239,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
|
|||
let mut any_eq = false;
|
||||
let mut any_ambiguous = false;
|
||||
|
||||
for ty in rhs_tuple.all_elements() {
|
||||
for ty in rhs_tuple.all_elements().copied() {
|
||||
let eq_result = self.infer_binary_type_comparison(
|
||||
Type::Tuple(lhs),
|
||||
ast::CmpOp::Eq,
|
||||
|
|
@ -7450,8 +7451,8 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
|
|||
return Ok(Type::unknown());
|
||||
};
|
||||
|
||||
let left_iter = left.elements();
|
||||
let right_iter = right.elements();
|
||||
let left_iter = left.elements().copied();
|
||||
let right_iter = right.elements().copied();
|
||||
|
||||
let mut builder = UnionBuilder::new(self.db());
|
||||
|
||||
|
|
@ -7695,7 +7696,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
|
|||
"tuple",
|
||||
value_node.into(),
|
||||
value_ty,
|
||||
tuple.display_minimum_length(),
|
||||
tuple.len().display_minimum(),
|
||||
int,
|
||||
);
|
||||
Type::unknown()
|
||||
|
|
@ -8856,7 +8857,7 @@ impl<'db> TypeInferenceBuilder<'db, '_> {
|
|||
let ty = if return_todo {
|
||||
todo_type!("PEP 646")
|
||||
} else {
|
||||
Type::tuple(self.db(), TupleType::new(self.db(), element_types))
|
||||
Type::tuple(TupleType::new(self.db(), element_types))
|
||||
};
|
||||
|
||||
// Here, we store the type for the inner `int, str` tuple-expression,
|
||||
|
|
|
|||
|
|
@ -19,7 +19,7 @@ impl<'db> Type<'db> {
|
|||
TupleType::homogeneous(db, Type::unknown())
|
||||
}
|
||||
(ClassType::Generic(alias), Some(KnownClass::Tuple)) => {
|
||||
Self::tuple(db, TupleType::new(db, alias.specialization(db).tuple(db)))
|
||||
Self::tuple(TupleType::new(db, alias.specialization(db).tuple(db)))
|
||||
}
|
||||
_ if class.class_literal(db).0.is_protocol(db) => {
|
||||
Self::ProtocolInstance(ProtocolInstanceType::from_class(class))
|
||||
|
|
|
|||
|
|
@ -184,6 +184,7 @@ impl ClassInfoConstraintFunction {
|
|||
tuple
|
||||
.tuple(db)
|
||||
.all_elements()
|
||||
.copied()
|
||||
.map(|element| self.generate_constraint(db, element)),
|
||||
),
|
||||
Type::ClassLiteral(class_literal) => {
|
||||
|
|
|
|||
File diff suppressed because it is too large
Load diff
|
|
@ -1,5 +1,4 @@
|
|||
use std::borrow::Cow;
|
||||
use std::cmp::Ordering;
|
||||
|
||||
use ruff_db::parsed::ParsedModuleRef;
|
||||
use rustc_hash::FxHashMap;
|
||||
|
|
@ -9,13 +8,12 @@ use ruff_python_ast::{self as ast, AnyNodeRef};
|
|||
use crate::Db;
|
||||
use crate::semantic_index::ast_ids::{HasScopedExpressionId, ScopedExpressionId};
|
||||
use crate::semantic_index::place::ScopeId;
|
||||
use crate::types::tuple::{FixedLengthTupleSpec, TupleSpec, TupleType};
|
||||
use crate::types::{Type, TypeCheckDiagnostics, infer_expression_types, todo_type};
|
||||
use crate::types::tuple::{ResizeTupleError, Tuple, TupleLength, TupleUnpacker};
|
||||
use crate::types::{Type, TypeCheckDiagnostics, infer_expression_types};
|
||||
use crate::unpack::{UnpackKind, UnpackValue};
|
||||
|
||||
use super::context::InferContext;
|
||||
use super::diagnostic::INVALID_ASSIGNMENT;
|
||||
use super::{KnownClass, UnionType};
|
||||
|
||||
/// Unpacks the value expression type to their respective targets.
|
||||
pub(crate) struct Unpacker<'db, 'ast> {
|
||||
|
|
@ -115,18 +113,13 @@ impl<'db, 'ast> Unpacker<'db, 'ast> {
|
|||
}
|
||||
ast::Expr::List(ast::ExprList { elts, .. })
|
||||
| ast::Expr::Tuple(ast::ExprTuple { elts, .. }) => {
|
||||
// Initialize the vector of target types, one for each target.
|
||||
//
|
||||
// This is mainly useful for the union type where the target type at index `n` is
|
||||
// going to be a union of types from every union type element at index `n`.
|
||||
//
|
||||
// For example, if the type is `tuple[int, int] | tuple[int, str]` and the target
|
||||
// has two elements `(a, b)`, then
|
||||
// * The type of `a` will be a union of `int` and `int` which are at index 0 in the
|
||||
// first and second tuple respectively which resolves to an `int`.
|
||||
// * Similarly, the type of `b` will be a union of `int` and `str` which are at
|
||||
// index 1 in the first and second tuple respectively which will be `int | str`.
|
||||
let mut target_types = vec![vec![]; elts.len()];
|
||||
let target_len = match elts.iter().position(ast::Expr::is_starred_expr) {
|
||||
Some(starred_index) => {
|
||||
TupleLength::Variable(starred_index, elts.len() - (starred_index + 1))
|
||||
}
|
||||
None => TupleLength::Fixed(elts.len()),
|
||||
};
|
||||
let mut unpacker = TupleUnpacker::new(self.db(), target_len);
|
||||
|
||||
let unpack_types = match value_ty {
|
||||
Type::Union(union_ty) => union_ty.elements(self.db()),
|
||||
|
|
@ -134,205 +127,75 @@ impl<'db, 'ast> Unpacker<'db, 'ast> {
|
|||
};
|
||||
|
||||
for ty in unpack_types.iter().copied() {
|
||||
// Deconstruct certain types to delegate the inference back to the tuple type
|
||||
// for correct handling of starred expressions.
|
||||
let ty = match ty {
|
||||
let tuple = match ty {
|
||||
Type::Tuple(tuple_ty) => Cow::Borrowed(tuple_ty.tuple(self.db())),
|
||||
Type::StringLiteral(string_literal_ty) => {
|
||||
// We could go further and deconstruct to an array of `StringLiteral`
|
||||
// with each individual character, instead of just an array of
|
||||
// `LiteralString`, but there would be a cost and it's not clear that
|
||||
// it's worth it.
|
||||
TupleType::from_elements(
|
||||
self.db(),
|
||||
std::iter::repeat_n(
|
||||
Type::LiteralString,
|
||||
string_literal_ty.python_len(self.db()),
|
||||
),
|
||||
)
|
||||
Cow::Owned(Tuple::from_elements(std::iter::repeat_n(
|
||||
Type::LiteralString,
|
||||
string_literal_ty.python_len(self.db()),
|
||||
)))
|
||||
}
|
||||
Type::LiteralString => Cow::Owned(Tuple::homogeneous(Type::LiteralString)),
|
||||
_ => {
|
||||
// TODO: Update our iterator protocol machinery to return a tuple
|
||||
// describing the returned values in more detail, when we can.
|
||||
Cow::Owned(Tuple::homogeneous(
|
||||
ty.try_iterate(self.db()).unwrap_or_else(|err| {
|
||||
err.report_diagnostic(&self.context, ty, value_expr);
|
||||
err.fallback_element_type(self.db())
|
||||
}),
|
||||
))
|
||||
}
|
||||
_ => ty,
|
||||
};
|
||||
|
||||
if let Type::Tuple(tuple_ty) = ty {
|
||||
let tuple = self.tuple_ty_elements(target, elts, tuple_ty, value_expr);
|
||||
|
||||
let length_mismatch = match elts.len().cmp(&tuple.len()) {
|
||||
Ordering::Less => {
|
||||
if let Some(builder) =
|
||||
self.context.report_lint(&INVALID_ASSIGNMENT, target)
|
||||
{
|
||||
if let Err(err) = unpacker.unpack_tuple(tuple.as_ref()) {
|
||||
unpacker
|
||||
.unpack_tuple(&Tuple::homogeneous(Type::unknown()))
|
||||
.expect("adding a homogeneous tuple should always succeed");
|
||||
if let Some(builder) = self.context.report_lint(&INVALID_ASSIGNMENT, target)
|
||||
{
|
||||
match err {
|
||||
ResizeTupleError::TooManyValues => {
|
||||
let mut diag =
|
||||
builder.into_diagnostic("Too many values to unpack");
|
||||
diag.set_primary_message(format_args!(
|
||||
"Expected {}",
|
||||
elts.len(),
|
||||
target_len.display_minimum(),
|
||||
));
|
||||
diag.annotate(self.context.secondary(value_expr).message(
|
||||
format_args!("Got {}", tuple.len().display_minimum()),
|
||||
));
|
||||
diag.annotate(
|
||||
self.context
|
||||
.secondary(value_expr)
|
||||
.message(format_args!("Got {}", tuple.len())),
|
||||
);
|
||||
}
|
||||
true
|
||||
}
|
||||
Ordering::Greater => {
|
||||
if let Some(builder) =
|
||||
self.context.report_lint(&INVALID_ASSIGNMENT, target)
|
||||
{
|
||||
ResizeTupleError::TooFewValues => {
|
||||
let mut diag =
|
||||
builder.into_diagnostic("Not enough values to unpack");
|
||||
diag.set_primary_message(format_args!(
|
||||
"Expected {}",
|
||||
elts.len(),
|
||||
target_len.display_minimum(),
|
||||
));
|
||||
diag.annotate(self.context.secondary(value_expr).message(
|
||||
format_args!("Got {}", tuple.len().display_maximum()),
|
||||
));
|
||||
diag.annotate(
|
||||
self.context
|
||||
.secondary(value_expr)
|
||||
.message(format_args!("Got {}", tuple.len())),
|
||||
);
|
||||
}
|
||||
true
|
||||
}
|
||||
Ordering::Equal => false,
|
||||
};
|
||||
|
||||
for (index, ty) in tuple.elements().enumerate() {
|
||||
if let Some(element_types) = target_types.get_mut(index) {
|
||||
if length_mismatch {
|
||||
element_types.push(Type::unknown());
|
||||
} else {
|
||||
element_types.push(ty);
|
||||
}
|
||||
}
|
||||
}
|
||||
} else {
|
||||
let ty = if ty.is_literal_string() {
|
||||
Type::LiteralString
|
||||
} else {
|
||||
ty.try_iterate(self.db()).unwrap_or_else(|err| {
|
||||
err.report_diagnostic(&self.context, ty, value_expr);
|
||||
err.fallback_element_type(self.db())
|
||||
})
|
||||
};
|
||||
// Both `elts` and `target_types` are guaranteed to have the same length.
|
||||
for (element, target_type) in elts.iter().zip(&mut target_types) {
|
||||
if element.is_starred_expr() {
|
||||
target_type.push(
|
||||
KnownClass::List.to_specialized_instance(self.db(), [ty]),
|
||||
);
|
||||
} else {
|
||||
target_type.push(ty);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
for (index, element) in elts.iter().enumerate() {
|
||||
// SAFETY: `target_types` is initialized with the same length as `elts`.
|
||||
let element_ty = match target_types[index].as_slice() {
|
||||
[] => Type::unknown(),
|
||||
types => UnionType::from_elements(self.db(), types),
|
||||
};
|
||||
self.unpack_inner(element, value_expr, element_ty);
|
||||
// We constructed unpacker above using the length of elts, so the zip should
|
||||
// consume the same number of elements from each.
|
||||
for (target, value_ty) in elts.iter().zip(unpacker.into_types()) {
|
||||
self.unpack_inner(target, value_expr, value_ty);
|
||||
}
|
||||
}
|
||||
_ => {}
|
||||
}
|
||||
}
|
||||
|
||||
/// Returns the [`Type`] elements inside the given [`TupleType`] taking into account that there
|
||||
/// can be a starred expression in the `elements`.
|
||||
///
|
||||
/// `value_expr` is an AST reference to the value being unpacked. It is
|
||||
/// only used for diagnostics.
|
||||
fn tuple_ty_elements(
|
||||
&self,
|
||||
expr: &ast::Expr,
|
||||
targets: &[ast::Expr],
|
||||
tuple_ty: TupleType<'db>,
|
||||
value_expr: AnyNodeRef<'_>,
|
||||
) -> Cow<'_, FixedLengthTupleSpec<'db>> {
|
||||
let TupleSpec::Fixed(tuple) = tuple_ty.tuple(self.db()) else {
|
||||
let todo = todo_type!("Unpack variable-length tuple");
|
||||
return Cow::Owned(FixedLengthTupleSpec::from_elements(targets.iter().map(
|
||||
|target| {
|
||||
if target.is_starred_expr() {
|
||||
KnownClass::List.to_specialized_instance(self.db(), [todo])
|
||||
} else {
|
||||
todo
|
||||
}
|
||||
},
|
||||
)));
|
||||
};
|
||||
|
||||
// If there is a starred expression, it will consume all of the types at that location.
|
||||
let Some(starred_index) = targets.iter().position(ast::Expr::is_starred_expr) else {
|
||||
// Otherwise, the types will be unpacked 1-1 to the targets.
|
||||
return Cow::Borrowed(tuple);
|
||||
};
|
||||
|
||||
if tuple.len() >= targets.len() - 1 {
|
||||
// This branch is only taken when there are enough elements in the tuple type to
|
||||
// combine for the starred expression. So, the arithmetic and indexing operations are
|
||||
// safe to perform.
|
||||
let mut element_types = FixedLengthTupleSpec::with_capacity(targets.len());
|
||||
let tuple_elements = tuple.elements_slice();
|
||||
|
||||
// Insert all the elements before the starred expression.
|
||||
// SAFETY: Safe because of the length check above.
|
||||
element_types.extend_from_slice(&tuple_elements[..starred_index]);
|
||||
|
||||
// The number of target expressions that are remaining after the starred expression.
|
||||
// For example, in `(a, *b, c, d) = ...`, the index of starred element `b` is 1 and the
|
||||
// remaining elements after that are 2.
|
||||
let remaining = targets.len() - (starred_index + 1);
|
||||
|
||||
// This index represents the position of the last element that belongs to the starred
|
||||
// expression, in an exclusive manner. For example, in `(a, *b, c) = (1, 2, 3, 4)`, the
|
||||
// starred expression `b` will consume the elements `Literal[2]` and `Literal[3]` and
|
||||
// the index value would be 3.
|
||||
let starred_end_index = tuple.len() - remaining;
|
||||
|
||||
// SAFETY: Safe because of the length check above.
|
||||
let starred_element_types = &tuple_elements[starred_index..starred_end_index];
|
||||
|
||||
element_types.push(KnownClass::List.to_specialized_instance(
|
||||
self.db(),
|
||||
[if starred_element_types.is_empty() {
|
||||
Type::unknown()
|
||||
} else {
|
||||
UnionType::from_elements(self.db(), starred_element_types)
|
||||
}],
|
||||
));
|
||||
|
||||
// Insert the types remaining that aren't consumed by the starred expression.
|
||||
// SAFETY: Safe because of the length check above.
|
||||
element_types.extend_from_slice(&tuple_elements[starred_end_index..]);
|
||||
|
||||
Cow::Owned(element_types)
|
||||
} else {
|
||||
if let Some(builder) = self.context.report_lint(&INVALID_ASSIGNMENT, expr) {
|
||||
let mut diag = builder.into_diagnostic("Not enough values to unpack");
|
||||
diag.set_primary_message(format_args!("Expected {} or more", targets.len() - 1));
|
||||
diag.annotate(
|
||||
self.context
|
||||
.secondary(value_expr)
|
||||
.message(format_args!("Got {}", tuple.len())),
|
||||
);
|
||||
}
|
||||
|
||||
Cow::Owned(FixedLengthTupleSpec::from_elements(targets.iter().map(
|
||||
|target| {
|
||||
if target.is_starred_expr() {
|
||||
KnownClass::List.to_specialized_instance(self.db(), [Type::unknown()])
|
||||
} else {
|
||||
Type::unknown()
|
||||
}
|
||||
},
|
||||
)))
|
||||
}
|
||||
}
|
||||
|
||||
pub(crate) fn finish(mut self) -> UnpackResult<'db> {
|
||||
self.targets.shrink_to_fit();
|
||||
UnpackResult {
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue