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Is it possible to read parameterized/polymorphic case classes ?
See original GitHub issueIssue Description
I’m sorry for flooding upicke with issues 😃 But I got utterly stuck on reading :
case class What[E](a: TypeThatHasAReaderAvailable[E])
read[What[Ever]](xyz)
The problem is here : https://github.com/lihaoyi/upickle/blob/ccd23c491ebec51a091ffc49b709d067fa1c1df8/shared/main/scala/upickle/Macros.scala#L121
[info] exception during macro expansion:
[info] scala.ScalaReflectionException: value apply encapsulates multiple overloaded alternatives and cannot be treated as a method. Consider invoking `<offending symbol>.asTerm.alternatives` and manually picking the required method
[info] at scala.reflect.api.Symbols$SymbolApi$class.asMethod(Symbols.scala:228)
[info] at scala.reflect.internal.Symbols$SymbolContextApiImpl.asMethod(Symbols.scala:82)
[info] at upickle.Macros$.picklerFor(Macros.scala:121)
[info] at upickle.Macros$.macroRImpl(Macros.scala:32)
[info] val res = read[ResponseMessage[Vertex]](x.data.toString)
[info]
I tried even invoke the macro supplying the type parameters directly to it, but it failed the same way :
import scala.language.experimental.macros
def macroR[T]: Reader[T] = macro Macros.macroRImpl[T]
val a = macroR[What[Ever]]
Would you please give me a hint here?
Issue Analytics
- State:
- Created 9 years ago
- Comments:7 (6 by maintainers)
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@lihaoyi I think that should be mentioned in the documentation.
@lihaoyi you were right, I must have made a mistake somewhere else.
is really valid.