Generically convert thrown exceptions to an Either

exceptiontoeither.scala

  /**
   * Catch exceptions to create an `Either` value.
   *
   * Useful when you want to deal an API that reports failure conditions using
   * exceptions. This method allows catching exceptions and converting them to
   * `Left` values.
   * 
   * An advantage vs using `scala.util.Try` is that you have full control over
   * which exceptions are caught.
   *
   * @param block The block of code to catch exceptions from.
   * @param catcher The exception catcher. Any exceptions not caught by
   *                this will be thrown as normal.
   * @tparam A The type of the error value returned if an exception is caught.
   * @tparam B The type of the result if no exceptions are thrown.
   * @return The block's value if no exceptions are thrown, or an error value
   *         if an exception is thrown and caught by `catcher`.
   */
  def eitherCatch[A, B](block: => B)(catcher: PartialFunction[Throwable, A]): Either[A, B] = {
    try {
      Right(block)
    }
    catch catcher.andThen(Left(_))
  }

object Example {
 
 val result: Either[String, Array[Byte]] = eitherCatch {
   Files.readAllBytes(file)
 } {
   case e: IOException => e.toString
 }

}