Enhancement/2025 01 make decoder support either

[takapi327]

Implementation Details

Modified to allow Either to be used during Decoder construction.

This allows us to construct a process for cases that do not match the following pattern

enum Status(val code: Int):
  case InActive extends Status(0)
  case Active extends Status(1)

given Decoder[Status] = Decoder[Int].emap {
  case 0 => Right(Status.InActive)
  case 1 => Right(Status.Active)
  case unknown => Left(s"$unknown is Unknown Status code")
}

This modification allows Codec to use Either for construction.

given Codec[Status] = Codec[Int].eimap {
  case 0 => Right(Status.InActive)
  case 1 => Right(Status.Active)
  case unknown => Left(s"$unknown is Unknown Status code")
}(_.code)

Pull Request Checklist

• Wrote unit and integration tests
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code formatting by scalafmt (sbt scalafmtAll command execution)
• Add copyright headers to new files

References