sbopt is a little command line options builder library.
Given the following values
val hour : Option[String] = Some("18")
val dryRun : Boolean = true
You want to build arguments to call another process
val hourArgs = hour.map(v => Seq("--hour", v)).getOrElse(Nil)
val dryRunArgs = if (dryRun) Seq("--flag") else Nil
val allArgs = hourArgs ++ dryRunArgs
with this library, you can simply do
args(opt("hour", hour), flag("dry-run", dryRun))
Here are some usages for building arguments :
- with a
Stringoption
@ args(opt("name", "value"))
ArrayBuffer("--name", "value")
- with an
Intoption
@ args(opt("name", 42))
ArrayBuffer("--name", "42")
- with an
Optionoption
@ args(opt("name", Some("value")))
ArrayBuffer("--name", "value")
- with a
Listoption (values are separated by a comma)
@ args(opt("name", List("A", "B")))
ArrayBuffer("--name", "A,B")
- with a
Tupleoption (values are separated by an equal)
@ args(opt("name", ("key", "value")))
ArrayBuffer("--name", "key=value")
- with 2 options
@ args(opt("name", "value"), opt("other", "XXX"))
ArrayBuffer("--name", "value", "--other", "XXX")
- with a repeated option
@ args(opt("name", "A"), opt("name", "B"))
ArrayBuffer("--name", "A", "--name", "B")
- with a repeated option, by using a dedicated helper
@ args(opts("name", List("A", "B")))
ArrayBuffer("--name", "A", "--name", "B")
- with an heterogeneous repeated option
@ args(opts("name", "value", 42))
ArrayBuffer("--name", "value", "--name", "42")
- putting it all together (a.k.a. calling spark-submit in a programmatic way)
@ args(opts("conf", ("verbose", true), ("spark.yarn.maxAppAttempts", 1), ("spark.yarn.jars", List(java.nio.file.Paths.get("/path1"), java.nio.file.Paths.get("/path2")))))
ArrayBuffer("--conf", "verbose=true", "--conf", "spark.yarn.maxAppAttempts=1", "--conf", "spark.yarn.jars=/path1,/path2")
- with a discardable (empty String or None) value
@ args(opt("name", ""))
ArrayBuffer()
@ args(opt[String]("name", None))
ArrayBuffer()
sbopt comes with support for many types, most of them from the standard Java and Scala libraries. When using those types, users don’t have to provide anything else in order to be able to build an argument.
The currently supported basic types are:
StringBooleanInt,Long,Float,Doublejava.io.Filejava.nio.file.PathTuple2OptionList
sbopt can be extended to support those types. To do so, an instance for the Encoder type class must be provided.
class WrappedString(val self: String)
implicit val wrappedStringEncoder: Encoder[WrappedString] = _.self
When you can convert your type to a type that has an instance of Encoder
class WrappedInt(val self: Int)
implicit val wrappedIntEncoder: Encoder[WrappedInt] = Encoder.from(_.self)