io.github.cloudify.scala.spdf.Parameter.scala Maven / Gradle / Ivy
package io.github.cloudify.scala.spdf
/**
* Describes a command line option
*/
trait Parameter[T] {
/**
* The underlying value of this option
*/
private var underlying: Option[T] = None
/**
* The commandline name for this parameter
*/
val name: String
/**
* The optional default value for this parameter
*/
val default: Option[T] = None
/**
* Sets a new value for this parameter
*/
def :=(newValue: T): Unit = underlying = Some(newValue)
/**
* Converts this option to a sequence of strings to be appended to the
* command line
*/
def toParameter(implicit shower: ParamShow[T]): Iterable[String] = value match {
case Some(v) => shower.show(name, v)
case _ => Iterable.empty
}
/**
* Provides the current value for the option
*/
private def value: Option[T] = underlying orElse default
}
object Parameter {
/**
* Creates a new CommandOption with the specified name and default value
*/
def apply[T : ParamShow](commandName: String, defaultValue: T): Parameter[T] =
new Parameter[T] {
override val name: String = commandName
override val default: Option[T] = Some(defaultValue)
}
/**
* Creates a new CommandOption with the specified name
*/
def apply[T : ParamShow](commandName: String): Parameter[T] =
new Parameter[T] {
override val name: String = commandName
override val default: Option[T] = None
}
}