Cyclic reference for top-level definitions of recursive match types

[flomebul]

The following exemple no more accepted

  type LeafElem[X] = X match {
      case String => Char
      case Array[t] => LeafElem[t]
      case Iterable[t] => LeafElem[t]
      case AnyVal => X
    }

with the following error

-- Error: recursive.scala:11:7 -------------------------------------------------
11 |  type LeafElem[X] = X match {
   |       ^
   |illegal cyclic reference: match ... (caught cyclic reference) ... of      |type LeafElem refers back to the type itself

[DReigada]

This seems to still be happening for top level definitions of recursive match types

[flomebul]

For information, look like the code is accepted by dotr,but not by dotc.

[kubukoz]

Indeed, it seems like the issue is top level definitions + recursive match types. I just wasted some time fighting it :P

[flomebul]

Having a look to the regression "tests/pos/6362.scala", my feeling is that it does not cover the case. Is it possible to rewrite-it without the "object Test" encapsulation, so that the "match type" is really at top level?

[smarter]

Fixed by #9001.