represent document ids by (long) int, to benefit from the somewhat faster Inttab in ML (LinearSet in Scala is invariably indexed by native object ids);
/* Title: Pure/PIDE/document.scala
Author: Makarius
Document as collection of named nodes, each consisting of an editable
list of commands.
*/
package isabelle
import scala.collection.mutable
import scala.annotation.tailrec
object Document
{
/* formal identifiers */
type Version_ID = Long
type Command_ID = Long
type State_ID = Long
val NO_ID = 0L
def parse_id(s: String): Long = java.lang.Long.parseLong(s)
def print_id(id: Long): String = id.toString
/** named document nodes **/
object Node
{
val empty: Node = new Node(Linear_Set())
def command_starts(commands: Iterator[Command], offset: Int = 0): Iterator[(Command, Int)] =
{
var i = offset
for (command <- commands) yield {
val start = i
i += command.length
(command, start)
}
}
}
class Node(val commands: Linear_Set[Command])
{
/* command ranges */
def command_starts: Iterator[(Command, Int)] =
Node.command_starts(commands.iterator)
def command_start(cmd: Command): Option[Int] =
command_starts.find(_._1 == cmd).map(_._2)
def command_range(i: Int): Iterator[(Command, Int)] =
command_starts dropWhile { case (cmd, start) => start + cmd.length <= i }
def command_range(i: Int, j: Int): Iterator[(Command, Int)] =
command_range(i) takeWhile { case (_, start) => start < j }
def command_at(i: Int): Option[(Command, Int)] =
{
val range = command_range(i)
if (range.hasNext) Some(range.next) else None
}
def proper_command_at(i: Int): Option[Command] =
command_at(i) match {
case Some((command, _)) =>
commands.reverse_iterator(command).find(cmd => !cmd.is_ignored)
case None => None
}
}
/* initial document */
val init: Document =
{
val doc = new Document(NO_ID, Map().withDefaultValue(Node.empty), Map())
doc.assign_states(Nil)
doc
}
/** changes of plain text, eventually resulting in document edits **/
type Node_Text_Edit = (String, List[Text_Edit]) // FIXME None: remove
type Edit[C] =
(String, // node name
Option[List[(Option[C], Option[C])]]) // None: remove, Some: insert/remove commands
abstract class Snapshot
{
val document: Document
val node: Document.Node
val is_outdated: Boolean
def convert(offset: Int): Int
def revert(offset: Int): Int
}
object Change
{
val init = new Change(NO_ID, None, Nil, Future.value(Nil, Document.init))
}
class Change(
val id: Version_ID,
val parent: Option[Change],
val edits: List[Node_Text_Edit],
val result: Future[(List[Edit[Command]], 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 snapshot(name: String, pending_edits: List[Text_Edit]): Snapshot =
{
val latest = Change.this
val stable = latest.ancestors.find(_.is_assigned)
require(stable.isDefined)
val edits =
(pending_edits /: latest.ancestors.takeWhile(_ != stable.get))((edits, change) =>
(for ((a, eds) <- change.edits if a == name) yield eds).flatten ::: edits)
lazy val reverse_edits = edits.reverse
new Snapshot {
val document = stable.get.join_document
val node = document.nodes(name)
val is_outdated = !(pending_edits.isEmpty && latest == stable.get)
def convert(offset: Int): Int = (offset /: edits)((i, edit) => edit.convert(i))
def revert(offset: Int): Int = (offset /: reverse_edits)((i, edit) => edit.revert(i))
}
}
}
/** editing **/
def text_edits(session: Session, old_doc: Document, new_id: Version_ID,
edits: List[Node_Text_Edit]): (List[Edit[Command]], Document) =
{
require(old_doc.assignment.is_finished)
/* unparsed dummy commands */
def unparsed(source: String) =
new Command(NO_ID, List(Token(Token.Kind.UNPARSED, source)))
def is_unparsed(command: Command) = command.id == NO_ID
/* phase 1: edit individual command source */
@tailrec def edit_text(eds: List[Text_Edit],
commands: Linear_Set[Command]): Linear_Set[Command] =
{
eds match {
case e :: es =>
Node.command_starts(commands.iterator).find {
case (cmd, cmd_start) =>
e.can_edit(cmd.source, cmd_start) ||
e.is_insert && e.start == cmd_start + cmd.length
} match {
case Some((cmd, cmd_start)) if e.can_edit(cmd.source, cmd_start) =>
val (rest, text) = e.edit(cmd.source, cmd_start)
val new_commands = commands.insert_after(Some(cmd), unparsed(text)) - cmd
edit_text(rest.toList ::: es, new_commands)
case Some((cmd, cmd_start)) =>
edit_text(es, commands.insert_after(Some(cmd), unparsed(e.text)))
case None =>
require(e.is_insert && e.start == 0)
edit_text(es, commands.insert_after(None, unparsed(e.text)))
}
case Nil => commands
}
}
/* phase 2: recover command spans */
@tailrec def parse_spans(commands: Linear_Set[Command]): Linear_Set[Command] =
{
commands.iterator.find(is_unparsed) match {
case Some(first_unparsed) =>
val first =
commands.reverse_iterator(first_unparsed).find(_.is_command) getOrElse commands.head
val last =
commands.iterator(first_unparsed).find(_.is_command) getOrElse commands.last
val range =
commands.iterator(first).takeWhile(_ != last).toList ::: List(last)
val sources = range.flatMap(_.span.map(_.source))
val spans0 = Thy_Syntax.parse_spans(session.current_syntax.scan(sources.mkString))
val (before_edit, spans1) =
if (!spans0.isEmpty && first.is_command && first.span == spans0.head)
(Some(first), spans0.tail)
else (commands.prev(first), spans0)
val (after_edit, spans2) =
if (!spans1.isEmpty && last.is_command && last.span == spans1.last)
(Some(last), spans1.take(spans1.length - 1))
else (commands.next(last), spans1)
val inserted = spans2.map(span => new Command(session.create_id(), span))
val new_commands =
commands.delete_between(before_edit, after_edit).append_after(before_edit, inserted)
parse_spans(new_commands)
case None => commands
}
}
/* phase 3: resulting document edits */
{
val doc_edits = new mutable.ListBuffer[Edit[Command]]
var nodes = old_doc.nodes
var former_states = old_doc.assignment.join
for ((name, text_edits) <- edits) {
val commands0 = nodes(name).commands
val commands1 = edit_text(text_edits, commands0)
val commands2 = parse_spans(commands1) // FIXME somewhat slow
val removed_commands = commands0.iterator.filter(!commands2.contains(_)).toList
val inserted_commands = commands2.iterator.filter(!commands0.contains(_)).toList
val cmd_edits =
removed_commands.reverse.map(cmd => (commands0.prev(cmd), None)) :::
inserted_commands.map(cmd => (commands2.prev(cmd), Some(cmd)))
doc_edits += (name -> Some(cmd_edits))
nodes += (name -> new Node(commands2))
former_states --= removed_commands
}
(doc_edits.toList, new Document(new_id, nodes, former_states))
}
}
}
class Document(
val id: Document.Version_ID,
val nodes: Map[String, Document.Node],
former_states: Map[Command, Command]) // FIXME !?
{
/* command state assignment */
val assignment = Future.promise[Map[Command, Command]]
def await_assignment { assignment.join }
@volatile private var tmp_states = former_states
def assign_states(new_states: List[(Command, Command)])
{
assignment.fulfill(tmp_states ++ new_states)
tmp_states = Map()
}
def current_state(cmd: Command): State =
{
require(assignment.is_finished)
(assignment.join).get(cmd) match {
case Some(cmd_state) => cmd_state.current_state
case None => new State(cmd, Command.Status.UNDEFINED, 0, Nil, cmd.empty_markup)
}
}
}