decline

A composable command-line parser, inspired by optparse-applicative and built on cats.

import cats.implicits._
import com.monovore.decline._

object HelloWorld extends CommandApp(
  name = "hello-world",
  header = "Says hello!",
  main = {
    val userOpt = 
      Opts.option[String]("target", help = "Person to greet.")
        .withDefault("world")
    
    val quietOpt = Opts.flag("quiet", help = "Whether to be quiet.").orFalse

    (userOpt |@| quietOpt).map { (user, quiet) => 

      if (quiet) println("...")
      else println(s"Hello $user!")
    }
  }
)

To get started, please visit monovore.com/decline!