package sbt
package complete
import History.number
import java.io.File
final class History private(val lines: IndexedSeq[String], val path: Option[File], error: String => Unit) extends NotNull
{
private def reversed = lines.reverse
def all: Seq[String] = lines
def size = lines.length
def !! : Option[String] = !- (1)
def apply(i: Int): Option[String] = if(0 <= i && i < size) Some( lines(i) ) else { error("Invalid history index: " + i); None }
def !(i: Int): Option[String] = apply(i)
def !(s: String): Option[String] =
number(s) match
{
case Some(n) => if(n < 0) !- (-n) else apply(n)
case None => nonEmpty(s) { reversed.find(_.startsWith(s)) }
}
def !- (n: Int): Option[String] = apply(size - n - 1)
def !?(s: String): Option[String] = nonEmpty(s) { reversed.drop(1).find(_.contains(s)) }
private def nonEmpty[T](s: String)(act: => Option[T]): Option[T] =
if(s.isEmpty)
{
error("No action specified to history command")
None
}
else
act
def list(historySize: Int, show: Int): Seq[String] =
lines.toList.drop((lines.size - historySize) max 0).zipWithIndex.map { case (line, number) => " " + number + " " + line }.takeRight(show max 1)
}
object History
{
def apply(lines: Seq[String], path: Option[File], error: String => Unit): History = new History(lines.toIndexedSeq, path, error)
def number(s: String): Option[Int] =
try { Some(s.toInt) }
catch { case e: NumberFormatException => None }
}