SIP-64 / Scala 3.6.2 compatibility - Support for Context Bounded Associated Types / Type Members

[Dessix]

Is your feature request related to a problem? Please describe.

import cats.{Show, Traverse}

trait Foo:
  type A: Show
  def a: Iterable[A]

trait Bar extends Foo:
  override type A: {Show, Traverse}
  type B: {Show, Traverse}

These two syntax additions from SIP-64 are valid as released in Scala 3.6.2 but appear to be taken as syntax errors under Metals 1.45.1.

This issue does not (yet) contain an exhaustive set of changes from SIP-64.

Describe the solution you'd like

Syntax support for the following:

• "naming context bounds, as in A: Monoid as a"
• "a new syntax for multiple context bounds, as in A: {Monoid, Ord}"
  As described in SIP-64.

Describe alternatives you've considered

Not using Scala 3.6.2's new features.

Additional context

Scalafmt appears to have added support for the new given syntax from SIP-64 in their PR #4656. Unfortunately, theirs does not also include code to support the new context bounds. This aspect does appear to be supported by Metals as of version 1.45.1.

Search terms

associated types, type members, context bounds

[tgodzik]

Thanks for reporting! This should be fixed by scalameta/scalameta#4099 so once the new version is out we can bump it in Metals