illustration of my usage of scala-optparse-applicative

output.txt

$ java -jar ./target/scala-2.11/actionstat-builtwith-load-assembly-0.0.154-g3030fdc-dirty.jar --help
Invalid option `--help'

Usage: builtwith-load <FILE> (-a|--address <ADDRESS>) (-k|--keyspace <NAME>) (-t|--table <NAME>)
                      (-T|--timestamp <NAME>)
  Loads hosting provider data from a zip file generated by a Builtwith Firehose process
  to Cassandra.

ParseOpts.scala

package actionstat.builtwith.load
package config


import java.io.File
import java.lang.String

import scala.{ StringContext, Unit }
import scala.collection.immutable.List

import net.bmjames.opts
import net.bmjames.opts.InfoMod
import net.bmjames.opts.builder._
import net.bmjames.opts.types.{ Parser, ReadM }

import scalaz.{ Foldable, NonEmptyList }
import scalaz.concurrent.Task
import scalaz.syntax.apply._
import scalaz.syntax.foldable._


object ParseOpts {

  def run[F[_] : Foldable]
      (job: Config => Task[Unit], args: F[String])
      : Task[Unit] = {
    val argArray = args.toList.toArray
    Task
      .delay { opts execParser (argArray, progName, parserInfo) }
      .flatMap(job)
  }

  private def progName: String = "builtwith-load"

  private def parserInfo =
    opts info (parser, progDesc)

  private def progDesc: InfoMod[Config] =
    opts progDesc (
      """Loads hosting provider data from a zip file generated by a """ +
      """Builtwith Firehose process.""")

  // a small hack to deal with a bug
  //
  import net.bmjames.opts.types.ParserM.{ fromM, oneM, manyM }
  def some[A](p: Parser[A]): Parser[NonEmptyList[A]] =
    fromM((oneM(p) |@| manyM(p))(NonEmptyList.nel))

  private def parser: Parser[Config] = {

    val readFilenames: Parser[NonEmptyList[BuiltwithOutput]] =
      some(
        strArgument(
          help("zip file from Builtwith Firehose job"),
          metavar("<FILE>")) map { f => BuiltwithOutput(new File(f)) })

    val contactPoints: Parser[NonEmptyList[ContactPoint]] =
      some(
        strOption(
          short('a'),
          long("address"),
          help("IP or hostname of Cassandra server"),
          metavar("<ADDRESS>")) map ContactPoint)

    val keyspace: Parser[Keyspace] =
      strOption(
        short('k'),
        long("keyspace"),
        help("keyspace of table to load"),
        metavar("<NAME>")) map Keyspace

    val table: Parser[Table] =
      strOption(
        short('t'),
        long("table"),
        help("table to load"),
        metavar("<NAME>")) map Table

    val timestamp: Parser[FactTimestamp] = {
      val malformedMsg = "timestamp is not well-formed (ISO 8601 accepted)"
      option(
        eitherReader(FactTimestamp parse malformedMsg),
        short('T'),
        long("timestamp"),
        help("table to load"),
        metavar("<NAME>"))
    }

    (readFilenames |@|
      contactPoints |@|
      keyspace |@|
      table |@|
      timestamp)(Config.apply)

  }

}