Quick quiz:
Q: In a CFG, what does `a -> b -> c -> d` mean?
A: `a`, then `b`, then `c`, then `d`.
Q: In a CFG, what does `a -> b -> d; a -> c -> d` mean?
A: `a`, then `b` or `c`, then `d`.
Q: So how do you encode "a, then (b, then c) or (c, then b), then d`?
A: You can't.
Problem is, you need to, because that's what `a; run2({ b }, { c }); d`
does when `run2` has a contract that it calls both its lambda arguments
in-place: `shuffle(listOf(block1, block2)).forEach { it() }` is a
perfectly valid implementation for it, as little sense as that makes.
So that's what union nodes solve. When a node implements
`UnionNodeMarker`, its inputs are interpreted as "all visited in some
order" instead of the normal "one of the inputs is visited".
Currently this is used for data flow. It *should* also be used for
control flow, but it isn't. But it should be. But that's not so easy.
BTW, `try` exit is NOT a union node; although lambdas in one branch can
be completed according to types' of lambdas in another, data does not
flow between the branches anyway (since we don't know how much of the
`try` executed before jumping into `catch`, and `catch`es are mutually
exclusive) so a `try` expression is more like `when` than a function
call with called-in-place-exactly-once arguments. The fact that
`exitTryExpression` used `processUnionOfArguments` in a weird way
should've hinted at that, but now we know for certain.
Refactor the renderer, make BoundSymbolReferenceRenderer a static class
to prevent calling RenderIrElementVisitor's methods from it to avoid
infinite recursion in the future.
^KT-52677 Fixed
- Allow 'lateinit' for inline classes which underlying type
is suitable for 'lateinit'
- K2: report all problems related to 'lateinit' modifier
^KT-55052: Fixed
It's anyway safe to use avoidComprehensiveCheck = true because
during deserialization we're sure that we need DNN type because
it's been serialized as such.
- Ensure that typed equals parameter's type is a star projection of
corresponding inline class
- Make possible to declare typed equals that returns 'Nothing'
- Forbid type parameters in typed equals operator declaration
^KT-54909 fixed
^KT-54910 fixed
But not substitution overrides! This is important if the method called
is an intersection override where one of the intersected types is a
subtype of a generic type.
'findKotlinClassOrContent()' does not really distinguish between
outer class names and package path components, so it might return
'foo/bar/Baz.Boo' for 'foo/bar/Baz/Boo'. Possibly because
'findKotlinClassOrContent()' potentially returns a raw byte array,
ClassId checking is supposed to be performed in
'extractClassMetadata()'. For Java, it happens inside
'FirJavaFacade.findClass()', yet for Kotlin the check was absent.
pyos