I'm upgrading my scala project from version 2 to 3.
This is my build.sbt for version scala version 2
scalaVersion := "2.13.5"
version := "1.0.0"
libraryDependencies += "com.chuusai" %% "shapeless" % "2.3.7"
libraryDependencies += "org.scodec" %% "scodec-core" % "1.11.4"
libraryDependencies += "org.slf4j" % "slf4j-log4j12" % "1.7.31"
Below is sample scala code -
import scodec._
import scodec.codecs._
import scodec.bits._
import scodec.codecs.implicits._
import org.slf4j.LoggerFactory
object AkkaEventSerializer {
def toBinary(o: AnyRef): Array[Byte] = o match {
case e: Event => Codec.encode(e).require.toByteArray
case x => throw new Exception(s"unexpected object $x received which is ${x.getClass} type")
}
def fromBinary(bytes: Array[Byte], manifest: String): AnyRef = manifest match {
case EventManifest => Codec[Event].decode(BitVector.apply(bytes)).require.value
case x => throw new Exception(s"unexpected manifest $x in AdServerAkkaEventSerializer.fromBinary ")
}
final val EventManifest = classOf[Event].getName
val logger = LoggerFactory.getLogger(AkkaEventSerializer.getClass)
case class Event(etype: Int, cp: Option[Double], userId: Option[String], buyerId: Option[String] = None)
}
This is working fine for scala version 2.
Now I'm upgrading the scala version to 3.
Below is the build.sbt -
scalaVersion := "3.0.0"
version := "1.0.0"
crossScalaVersions := Seq("2.13.5", "3.0.0")
libraryDependencies += ("com.chuusai" %% "shapeless" % "2.3.7").cross(CrossVersion.for3Use2_13)
libraryDependencies += ("org.scodec" %% "scodec-core" % "1.11.4").cross(CrossVersion.for3Use2_13)
libraryDependencies += "org.slf4j" % "slf4j-log4j12" % "1.7.31"
Below is the code scala version 3 -
import scodec._
import scodec.codecs._
import scodec.bits._
import scodec.codecs.implicits._
import org.slf4j.LoggerFactory
import shapeless.~?>.idKeyWitness
import shapeless.~?>.idValueWitness
import shapeless.~?>.witness
object AkkaEventSerializer {
def toBinary(o: AnyRef): Array[Byte] = o match {
case e: Event => Codec.encode(e).require.toByteArray
case x => throw new Exception(s"unexpected object $x received which is ${x.getClass} type")
}
def fromBinary(bytes: Array[Byte], manifest: String): AnyRef = manifest match {
case EventManifest => Codec[Event].decode(BitVector.apply(bytes)).require.value
case x => throw new Exception(s"unexpected manifest $x in AdServerAkkaEventSerializer.fromBinary ")
}
final val EventManifest = classOf[Event].getName
val logger = LoggerFactory.getLogger(AkkaEventSerializer.getClass)
case class Event(etype: Int, cp: Option[Double], userId: Option[String], buyerId: Option[String] = None)
}
When I compile this program, I get below error -
[error] -- Error: /Users/rajkumar.natarajan/Documents/Coding/OS/scala3-maven-build-demo/src/main/scala/com/serialize/AkkaEventSerializer.scala:17:36 [error] 17 | case e: Event => Codec.encode(e).require.toByteArray [error] | ^ [error] |could not find Lazy implicit value of type scodec.Codec[com.serialize.AkkaEventSerializer.Event]. [error] |I found: [error] | [error] | shapeless.~?>.witness[Nothing, Nothing, T](shapeless.~?>.rel[Nothing, Nothing]) [error] |
[error] |But method witness in trait NatTRel0 does not match type shapeless.Lazy[scodec.Codec[com.serialize.AkkaEventSerializer.Event]]. [error] -- Error: /Users/rajkumar.natarajan/Documents/Coding/OS/scala3-maven-build-demo/src/main/scala/com/serialize/AkkaEventSerializer.scala:22:38 [error] 22 | case EventManifest => Codec[Event].decode(BitVector.apply(bytes)).require.value [error] | ^ [error] |could not find Lazy implicit value of type scodec.Codec[com.serialize.AkkaEventSerializer.Event]. [error] |I found:
[error] |
[error] | shapeless.~?>.witness[Nothing, Nothing, T](shapeless.~?>.rel[Nothing, Nothing]) [error] |
[error] |But method witness in trait NatTRel0 does not match type shapeless.Lazy[scodec.Codec[com.serialize.AkkaEventSerializer.Event]]. [error] two errors found [error] two errors found [error] (Compile / compileIncremental) Compilation failed
I know we can compile scala 2.13 code using scala 3 version. But I couldn't for this code.
How can I fix this error?