/* Title: Pure/Thy/thy_syntax.scala
Author: Makarius
Superficial theory syntax: tokens and spans.
*/
package isabelle
import scala.collection.mutable
import scala.annotation.tailrec
object Thy_Syntax
{
/** nested structure **/
object Structure
{
sealed abstract class Entry { def length: Int }
case class Block(val name: String, val body: List[Entry]) extends Entry
{
val length: Int = (0 /: body)(_ + _.length)
}
case class Atom(val command: Command) extends Entry
{
def length: Int = command.length
}
def parse(syntax: Outer_Syntax, root_name: String, text: CharSequence): Entry =
{
/* stack operations */
def buffer(): mutable.ListBuffer[Entry] = new mutable.ListBuffer[Entry]
var stack: List[(Int, String, mutable.ListBuffer[Entry])] = List((0, root_name, buffer()))
@tailrec def close(level: Int => Boolean)
{
stack match {
case (lev, name, body) :: (_, _, body2) :: rest if level(lev) =>
body2 += Block(name, body.toList)
stack = stack.tail
close(level)
case _ =>
}
}
def result(): Entry =
{
close(_ => true)
val (_, name, body) = stack.head
Block(name, body.toList)
}
def add(command: Command)
{
syntax.heading_level(command) match {
case Some(i) =>
close(_ >= i)
stack = (i, command.source, buffer()) :: stack
case None =>
}
stack.head._3 += Atom(command)
}
/* result structure */
val spans = parse_spans(syntax.scan(text))
spans.foreach(span => add(Command.span(span)))
result()
}
}
/** parse spans **/
def parse_spans(toks: List[Token]): List[List[Token]] =
{
val result = new mutable.ListBuffer[List[Token]]
val span = new mutable.ListBuffer[Token]
val whitespace = new mutable.ListBuffer[Token]
def flush(buffer: mutable.ListBuffer[Token])
{
if (!buffer.isEmpty) { result += buffer.toList; buffer.clear }
}
for (tok <- toks) {
if (tok.is_command) { flush(span); flush(whitespace); span += tok }
else if (tok.is_ignored) whitespace += tok
else { span ++= whitespace; whitespace.clear; span += tok }
}
flush(span); flush(whitespace)
result.toList
}
/** text edits **/
def text_edits(syntax: Outer_Syntax, previous: Document.Version,
edits: List[Document.Edit_Text]): (List[Document.Edit_Command], Document.Version) =
{
/* 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 =>
Document.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), Command.unparsed(text)) - cmd
edit_text(rest.toList ::: es, new_commands)
case Some((cmd, cmd_start)) =>
edit_text(es, commands.insert_after(Some(cmd), Command.unparsed(e.text)))
case None =>
require(e.is_insert && e.start == 0)
edit_text(es, commands.insert_after(None, Command.unparsed(e.text)))
}
case Nil => commands
}
}
/* phase 2: recover command spans */
@tailrec def recover_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).
dropWhile(_.newlines == 0).find(_.is_command) getOrElse commands.head
val last =
commands.iterator(first_unparsed).
dropWhile(_.newlines == 0).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 = parse_spans(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(Document.new_id(), span))
val new_commands =
commands.delete_between(before_edit, after_edit).append_after(before_edit, inserted)
recover_spans(new_commands)
case None => commands
}
}
/* resulting document edits */
{
val doc_edits = new mutable.ListBuffer[Document.Edit_Command]
var nodes = previous.nodes
edits foreach {
case (name, None) =>
doc_edits += (name -> None)
nodes -= name
case (name, Some(text_edits)) =>
val node = nodes(name)
val commands0 = node.commands
val commands1 = edit_text(text_edits, commands0)
val commands2 = recover_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 -> Document.Node(node.header, node.blobs, commands2))
}
(doc_edits.toList, new Document.Version(Document.new_id(), nodes))
}
}
}