julienrf / enum   3.1

MIT License GitHub
Scala versions: 2.13 2.12 2.11 2.10
Scala.js versions: 1.x 0.6


Yet another enumeration toolbox for Scala, powered by shapeless.


  • finds the values and labels of an enumeration and a mapping to go from a value to its label and vice versa.
  • finds the set of values of an enumeration ;
  • finds the set of value names of an enumeration ;

The artifacts are built for Scala 2.11, 2.12, 2.13 and Scala.js 0.6 and 1.x.


Just define your enumeration as a sealed trait (or a sealed abstract class) extended by case objects.

For instance:

sealed trait Foo
object Foo {
  case object Bar extends Foo
  case object Baz extends Foo


Use Enum.derived[A] to derive an Enum[A] value that provides several useful methods:

import enum.Enum

val enum: Enum[Foo] = Enum.derived[Foo]

enum.values == Set(Foo.Bar, Foo.Baz)
enum.labels == Set("Bar", "Baz")
enum.encode(Foo.Bar) == "Bar"
enum.decode("Baz") == Right(Foo.Baz)
enum.decode("invalid") == Left(DecodingFailure[Foo](Set("Bar", "Baz")))
enum.decodeOpt("Baz") == Some(Foo.Baz)

See the API documentation for more details.


Use Values.derived[A] to automatically gather all the A enumeration values as a Set[A]:

import enum.Values

val fooValues: Values[Foo] = Values.derived[Foo]

fooValues.values == Set(Foo.Bar, Foo.Baz)

See the API documentation for more details.


Use Labels.derived[A] to automatically gather all the A enumeration labels as a Set[String]:

import enum.Labels

val fooLabels: Labels[Foo] = Labels.derived[Foo]

fooLabels.labels == Set("Bar", "Baz")

See the API documentation for more details.


  • 3.1
    • Scala 2.12 and 2.13 support
  • 3.0
    • Breaking change: the companion object’s apply method that was used to derive enumerations has been renamed to derived. The apply method still exists but it now returns the implicitly available instance (your old code may still compile with the new version but might fail at runtime).
    • Remove package julienrf
  • 2.2
    • Update shapeless to 2.3.0 and Scala.js to 0.6.7
  • 2.1
    • Lessen derivation implicit priority
  • 2.0
    • Added support for implicit definitions in enumerations companion objects
  • 1.1
    • Added Enum[A]
  • 1.0
    • First release


This content is released under the MIT License.