Implement tracked members
#21761
Implement tracked members
#21761
Conversation
…behind a flag, reemove debugs and add some more tests
| if sym.allOverriddenSymbols.exists(_.flags.is(Tracked)) then | ||
| sym.setFlag(Tracked) | ||
| if sym.flags.is(Tracked) && tpt.isEmpty then | ||
| sym.info = rhs.tpe |
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It seems dangerous to set info here. This means that the symbol info gets modified when the val is type-checked, so it's not the same before and after in definition order.
Here is an example:
abstract class Vec:
tracked val size: Int
@main def main =
val v = new Vec:
val size0: size.type = 10 // error: found (10 : Int), required (size : Int)
val size = 10
val size1: size.type = 10 // okay, because size is known to be (10 : Int) hereI am wondering if the logic wouldn't be better placed in Namer.Completer, maybe setting the flag in completeInCreationContext and computing the precise member type in valOrDefDefSig? Have you thought about doing so? However this is not easy to do without causing cyclic references.
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I haven't been able to do exactly what I described above due to cyclic references, but I could move the whole setAbstractTrackedInfo to Namer.Completer: dotty-staging#53.
Still seems dirty to write over .info, but at least it's done directly when completing the symbol. What do you think?
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Yes, seemed dirty to me too, but it also seemed like the least intrusive way to do it. If moving the logic to Namer works, then it should be the better solution, so we can merge dotty-staging#53.
I would probably wait on Martin's opinion though. What do you think?
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Sounds good to me to wait on Martin's opinion.
And my PR currently fails picklings test actually.
closes #21754