Enumeratum module

kantan.xpath comes with an enumeratum module that can be used by adding the following dependency to your build.sbt:

libraryDependencies += "com.nrinaudo" %% "kantan.xpath-enumeratum" % "0.5.3"

Name-based enumerations

When working with enumerations of type Enum, you should import the following package:

import kantan.xpath.enumeratum._

And that’s pretty much it. You can now encode and decode your enumeration directly.

Let’s first set our types up:

import enumeratum._

sealed trait DummyEnum extends EnumEntry

object DummyEnum extends Enum[DummyEnum] {

  val values = findValues

  case object Hello   extends DummyEnum
  case object GoodBye extends DummyEnum
  case object Hi      extends DummyEnum
}

And a few further imports, to bring our enumeration and the kantan.csv syntax in scope:

import kantan.xpath.implicits._

We can then simply write the following:

"<foo><bar value='Hello'/></foo>".evalXPath[DummyEnum](xp"//bar/@value")
// res0: kantan.xpath.package.XPathResult[DummyEnum] = Right(value = Hello)

"<foo><bar value='GoodDay'/></foo>".evalXPath[DummyEnum](xp"//bar/@value")
// res1: kantan.xpath.package.XPathResult[DummyEnum] = Left(
//   value = TypeError(
//     message = "'GoodDay' is not a member of enumeration [Hello, GoodBye, Hi]"
//   )
// )

Value-based enumerations

For enumerations of type ValueEnum, you should import the following package:

import kantan.xpath.enumeratum.values._

And that’s pretty much it. You can now encode and decode your enumeration directly.

Let’s first set our types up:

import enumeratum.values._

sealed abstract class Greeting(val value: Int) extends IntEnumEntry

object Greeting extends IntEnum[Greeting] {

  val values = findValues

  case object Hello   extends Greeting(1)
  case object GoodBye extends Greeting(2)
  case object Hi      extends Greeting(3)
  case object Bye     extends Greeting(4)
}

And a few further imports, to bring our enumeration and the kantan.csv syntax in scope:

import kantan.xpath.implicits._

We can then simply write the following:

"<foo><bar value='1'/></foo>".evalXPath[Greeting](xp"//bar/@value")
// res3: kantan.xpath.package.XPathResult[Greeting] = Right(value = Hello)

"<foo><bar value='-1'/></foo>".evalXPath[Greeting](xp"//bar/@value")
// res4: kantan.xpath.package.XPathResult[Greeting] = Left(
//   value = TypeError(message = "'-1' is not in values [1, 2, 3, 4]")
// )