sbt/project/Status.scala

	import sbt._
	import Keys._
	import java.util.regex.Pattern

object Status
{
	lazy val isSnapshot = SettingKey[Boolean]("is-snapshot")
	lazy val publishStatus = SettingKey[String]("publish-status")

	def settings: Seq[Setting[_]] = Seq(
		isSnapshot <<= version(v => v.contains("-") && snapshotQualifier(v)),
		publishStatus <<= isSnapshot { snap => if(snap) "snapshots" else "releases" },
		commands += stampVersion
	)
	def stampVersion = Command.command("stamp-version") { state =>
		Project.extract(state).append((version in ThisBuild ~= stamp) :: Nil, state)
	}
	def stamp(v: String): String =
		if(v endsWith Snapshot)
			(v stripSuffix Snapshot) + "-" + timestampString(System.currentTimeMillis)
		else
			v
	def timestampString(time: Long): String =
	{
		val format = new java.text.SimpleDateFormat("yyyyMMdd-HHmmss")
		format.format(new java.util.Date(time))
	}
	final val Snapshot = "-SNAPSHOT"
	def snapshotQualifier(v: String) = !Pattern.matches(""".+-(M|Alpha|Beta|RC)?\d+""", v)
}