Desugar lazy val pattern bindings into lazy vals
#18879
Conversation
Fixes scala#18878 Reverts change in 54f6399 Example: ``` lazy val (a, b) = ... ``` desugars into ``` private lazy val t$1 = ... lazy val a = t$1._1 // before: def a = t$1._1 lazy val b = t$1._2 // before: def b = t$1._2 ``` Where `a` and `b` should be stable identifiers.
|
An alternative would be to introduce the internal concept of a |
|
I think the change to defs was done very expressedly since val's would not be sound. Mapping to lazy vals would be very expensive (if they are local they lead to boxing), so I think this is not a good fix either. It's best to leave things as they are, or tighten the screws further. A lazy val is not stable, since it is not a constructed value. We can get all the famous unsoundness tricks by replacing vals with lazy vals. So I think the most logical way forward is to declare that lazy val a = "bbb"
val b: a.type = a |
Fixes #18878.
Reverts change in 54f6399.
Example:
desugars into
Where
aandbshould be stable identifiers.