Kotlin: Parsing CLI options easily using ENUMs

enumCliOptionParsing.kt

    private inline fun <reified T : OptionEnum> tryParseEnumOption(enumArgumentDefault: T, arg: String): T? {
        val optionIntro = "--${enumArgumentDefault.optionName}"

        if (!arg.startsWith(optionIntro))
            return null

        if (arg == optionIntro || arg == optionIntro + "=" + enumArgumentDefault.optionValue)
            return enumArgumentDefault

        val valueStr = arg.substringAfter(optionIntro).removePrefix("=")

        val enumConstants = T::class.java.enumConstants
        return enumConstants.firstOrNull { it.optionName == valueStr }
            ?: throw CrucherConfigException("Unknown value for ${enumArgumentDefault.optionName}: $arg Try one of ${enumConstants.map { it.optionValue }}")
    }