Spelled-out number (string) to integer using ICU

Question

I need to convert a string to an integer. For example, I would like to convert sixth to 6.

I did the reverse one (6 → sixth) by using IBM's library ICU.

private val String.spellout: String
  get() {
    val esFormatter = RuleBasedNumberFormat(Locale.ENGLISH, RuleBasedNumberFormat.SPELLOUT)
    return esFormatter.format(this.toDouble(), "%spellout-ordinal")
  }

I would like to create another method that takes that spelled-out string and converts it to a double (sixth → 6)

Answer 1

After getting help from the comments here is my solution, in case anybody else needs it:

private val String.numberFromSpelledOut: Boolean
  get() {
    val esFormatter = RuleBasedNumberFormat(Locale.ENGLISH, RuleBasedNumberFormat.SPELLOUT)
    return try {
      return esFormatter.parse(this)
    } catch (e: ParseException) {
      ""
    }
  }

This should not throw an exception for invalid spelled-out inputs.