/* Title: Pure/PIDE/change.scala
Author: Fabian Immler, TU Munich
Author: Makarius
Changes of plain text.
*/
package isabelle
class Change(
val id: Isar_Document.Document_ID,
val parent: Option[Change],
val edits: List[Text_Edit],
val result: Future[(List[Document.Edit], Document)])
{
def ancestors: Iterator[Change] = new Iterator[Change]
{
private var state: Option[Change] = Some(Change.this)
def hasNext = state.isDefined
def next =
state match {
case Some(change) => state = change.parent; change
case None => throw new NoSuchElementException("next on empty iterator")
}
}
def join_document: Document = result.join._2
def is_assigned: Boolean = result.is_finished && join_document.assignment.is_finished
def edit(session: Session, edits: List[Text_Edit]): Change =
{
val new_id = session.create_id()
val result: Future[(List[Document.Edit], Document)] =
Future.fork {
val old_doc = join_document
old_doc.await_assignment
Document.text_edits(session, old_doc, new_id, edits)
}
new Change(new_id, Some(this), edits, result)
}
}