[CSGen] Allow _ pattern to be a hole
#60203
Conversation
|
@swift-ci please test |
|
I just looked at the code completion failure and the problem is that in this test case we fail to resolve the type for struct MyStruct<T> {
static subscript(x: Int, static defValue: T) -> MyStruct<T> {
fatalError()
}
subscript(x: Int, instance defValue: T) -> Int {
fatalError()
}
}
func test1() {
let _ = MyStruct<Int>()[#^INSTANCE_INT_BRACKET^#
}We don’t have this problem because it cannot be bound to a hole since the type variable is created by varType = CS.getType(boundExpr)->getRValueType();AFAICT the solution to this problem is to make variables at pattern decls as potentially incomplete, i.e. add // Delay resolution of pattern decls because we prefer to determine its type
// based on the expression it is assigned from. Also, if there is an error
// in the expression, we want to prefer creating the direct hole inside the
// expression, not at the pattern decl.
if (locator->isLastElement<LocatorPathElt::PatternDecl>()) {
return true;
}inside the |
|
I think it makes sense to do for |
|
@swift-ci please test |
The fix should support both named (i.e. `test(a)` and "any" patterns i.e. `test(_)`.
In cases like `case .test(_)` it might not be possible to establish a type of `_` and hole cannot be propagated to it from context if condition of switch is incorrect, so `_` just like a named pattern should be allowed to become a hole. Resolves: rdar://96997534
Instead of `CTP_Initialization` transform should use `CTP_CaseStmt` to identify the root correctly.
`_` pattern doesn't have a type, it's always contextual, so let's allow it to assume a type of initializer expression instead of creating a new type variable. This helps to makes sure that initializer would never get a placeholder type from `_` pattern it's associated with.
In cases like `.<name>(_)`, the `_` sub-pattern should not assume locator of the parent paren, just like it doesn't in case of tuple i.e. `.<name>(_, ...)` where each element gets a `PatternMatch(<elt>)` locator.
|
@swift-ci please test |
|
@swift-ci please test source compatibility |
2 similar comments
|
@swift-ci please test source compatibility |
|
@swift-ci please test source compatibility |
In cases like
case .test(_)it might not be possible toestablish a type of
_and hole cannot be propagated toit from context if condition of switch is incorrect, so
_just like a named pattern should be allowed to becomea hole.
Resolves: rdar://96997534