NonFatal

expect fun NonFatal(t: Throwable): Boolean

Extractor of non-fatal Throwable. Will not match fatal errors like VirtualMachineError (for example, OutOfMemoryError and StackOverflowError, subclasses of VirtualMachineError), ThreadDeath, LinkageError, InterruptedException. This will also not match CancellationException since that's a fatal exception in Kotlin for cancellation purposes.

Checks whether the passed t Throwable is NonFatal.

Return

true if the provided Throwable is to be considered non-fatal, or false if it is to be considered fatal

import arrow.*
import arrow.core.*

fun unsafeFunction(i: Int): String =
   when (i) {
        1 -> throw IllegalArgumentException("Non-Fatal")
        2 -> throw OutOfMemoryError("Fatal")
        else -> "Hello"
   }

fun main() {
  val nonFatal: Either<Throwable, String> =
  //sampleStart
  try {
     Either.Right(unsafeFunction(1))
  } catch (t: Throwable) {
    if (NonFatal(t)) {
        Either.Left(t)
    } else {
        throw t
    }
  }
  //sampleEnd
  println(nonFatal)
}

Parameters

the Throwable to check

actual fun NonFatal(t: Throwable): Boolean