Is it possible from a variable containing a class to list th

Question

Is it possible from a variable containing a class to list the possible value if the class extends enum

Shawn · Answer

just want to clarify is `value` in this example supposed to be an instance of `Class lt gt ` or are you attempting to match the type of `value` in the when expression

Giorgos Neokleous · Answer

Yes you can either have an exchaustive when ```when value Enum VALUE ONE class java gt A Enum Value 1 Enum VALUE TWO class java gt A Enum Value 2 ``` or ```when value Enum class java gt value enumConstants first it class java == value name ```

Shawn · Answer

if the content of `value` is `YourEnum class java` then I don t believe you ll be able to match against `Enum class java`

Shawn · Answer

but I might be misunderstanding the question

Wesley Acheson · Answer

< Shawn> I m actually trying to catch an exception from jackson When converting from Json it has a targetType field on InvalidFormatException So baically I m trying to list the possible values when someone enters a bad value So value is the class

Wesley Acheson · Answer

Yeah you are right here I was trying to simplify code currently looks like this ``` val type String = if formatException targetType == String class java a String else if formatException targetType == BigDecimal class java a Number else if formatException targetType == ZonedDateTime class java a Date else if Enum class java isAssignableFrom formatException targetType a value of type $ formatException targetType simpleName else formatException targetType simpleName``` but I was hoping to change back to a `when` when I got the values nailed down something like ``` val type String = when formatException targetType == String class java gt a String formatException targetType == BigDecimal class java gt a Number formatException targetType == ZonedDateTime class java gt a Date Enum class java isAssignableFrom formatException targetType gt a value of type $ formatException targetType simpleName Possible values here else gt formatException targetType simpleName ```

Shawn · Answer

You can definitely clean this up a bit with a `when` but the ability to print all the possible values is entirely predicated on whether or not Jackson gives you a `Class lt gt ` more specific than `Class lt Enum gt `

Wesley Acheson · Answer

I think the signature is class lt gt