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Add support for type parameters in annotations

See original GitHub issue

Follow up on issue #922 and pull request #925. I would like to add support for type parameters in annotations, both variable and type annotations. For example, define an annotation such as:

case class MyAnnotation[T](t: T) extends scala.annotation.StaticAnnotation

The out type of Annotations and TypeAnnotations would have the complete “reference” to type T.

Issue Analytics

State:
Created 3 years ago
Comments:6 (3 by maintainers)

Top GitHub Comments

1reaction

joroKr21commented, Apr 27, 2021

At least there is a step in that direction: #1019 Next would be, write a scalafix rule to replace Lazy and Strict with by-name implicits in the source code.

1reaction

joroKr21commented, Apr 27, 2021

@joroKr21 just wondering, is this going to work with Scala 3?

The Scala 3 story is a bit messy for shapeless because it uses a lot of macros.

This particular implementation won’t work on Scala 3. There is Shapeless 3 which works only with Scala 3 on the shapeless-3 branch. I don’t know much about it yet, so I can’t say what it offers in terms of annotations. Separately from that we have an issue to port shapeless 2 in some form to Scala 3: #1043 But nobody is working on that at the moment.

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