Interaction with Java's raw generic types is not possible

See for instance Javafx’s method https://docs.oracle.com/javase/8/javafx/api/javafx/scene/control/TreeTableView.html#setColumnResizePolicy-javafx.util.Callback- it takes a Callback<TreeTableView.ResizeFeatures,Boolean> but do notice that ResizeFeatures defines one generic parameter, the method defines a callback that takes it raw though. In scalac, you would pass a javafx.util.Callback[javafx.scene.control.TreeTableView.ResizeFeatures[_], Boolean] and it would typecheck, but with dottyc it doesn’t work

[smarter]

Yes, for now we’ve decided to not try to make the dotty Java source parser work with raw types since it’s usually pretty easy to fix Java code in your own project to not require raw types. We may change this in the future but it’s low priority.

[rcano]

Also worth noting, that if you happen to try and compile the java source in mixed mode with dotty (by placing the file under src/main/java), then when dotty parses the java file for the signatures you get this

[error] -- Error: TryMe.java:3:72 ------
[error] 3 |  public static <R> void ifYouCan(java.util.function.Function<java.util.List, R> f) {
[error]   |                                                              ^^^^^^^^^^^^^^
[error]   |          Type argument java.util.List has not the same kind as its bound