You don’t need any 3rd party library to do this: sealed trait MyTrait case object SubClass1 extends MyTrait case object SubClass2 extends MyTrait import scala.reflect.runtime.{universe => ru} val tpe = ru.typeOf[MyTrait] val clazz = tpe.typeSymbol.asClass // if you want to ensure the type is a sealed trait, // then you can use clazz.isSealed and clazz.isTrait … Read more
It is possible to create a TypeTag from a Class using Scala reflection, though I’m not sure if this implementation of TypeCreator is absolutely correct: import scala.reflect.runtime.universe._ def createOld[A](c: Class[A]): A = createNew { val mirror = runtimeMirror(c.getClassLoader) // obtain runtime mirror val sym = mirror.staticClass(c.getName) // obtain class symbol for `c` val tpe = … Read more
It is possible: import scala.reflect.runtime.universe._ import scala.reflect.api val mirror = runtimeMirror(getClass.getClassLoader) // whatever mirror you use to obtain the `Type` def backward[T](tpe: Type): TypeTag[T] = TypeTag(mirror, new api.TypeCreator { def apply[U <: api.Universe with Singleton](m: api.Mirror[U]) = if (m eq mirror) tpe.asInstanceOf[U # Type] else throw new IllegalArgumentException(s”Type tag defined in $mirror cannot be migrated … Read more
You can debug implicits at compile time: switch on compiler flag -Xlog-implicits try to resolve implicits manually (maybe specifying type parameters as well) and see compile errors implicitly[…](…manually…) use scala.reflect println(reify { implicitly[…] }.tree) (or switch on compiler flag -Xprint:typer) in order to see how implicits are resolved use IDE functionality to show implicits using … Read more