src/Pure/Thy/thy_syntax.scala
changeset 38374 7eb0f6991e25
parent 38373 e8197eea3cd0
child 38417 b8922ae21111
--- a/src/Pure/Thy/thy_syntax.scala	Sat Aug 14 11:52:24 2010 +0200
+++ b/src/Pure/Thy/thy_syntax.scala	Sat Aug 14 12:01:50 2010 +0200
@@ -1,17 +1,20 @@
 /*  Title:      Pure/Thy/thy_syntax.scala
     Author:     Makarius
 
-Superficial theory syntax: command spans.
+Superficial theory syntax: tokens and spans.
 */
 
 package isabelle
 
 
 import scala.collection.mutable
+import scala.annotation.tailrec
 
 
 object Thy_Syntax
 {
+  /** parse spans **/
+
   def parse_spans(toks: List[Token]): List[List[Token]] =
   {
     val result = new mutable.ListBuffer[List[Token]]
@@ -30,4 +33,101 @@
     flush(span); flush(whitespace)
     result.toList
   }
+
+
+
+  /** text edits **/
+
+  def text_edits(session: Session, old_doc: Document, edits: List[Document.Node_Text_Edit])
+      : (List[Document.Edit[Command]], Document) =
+  {
+    /* 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).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 = 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)
+          recover_spans(new_commands)
+
+        case None => commands
+      }
+    }
+
+
+    /* resulting document edits */
+
+    {
+      val doc_edits = new mutable.ListBuffer[Document.Edit[Command]]
+      var nodes = old_doc.nodes
+
+      for ((name, text_edits) <- edits) {
+        val commands0 = nodes(name).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 -> new Document.Node(commands2))
+      }
+      (doc_edits.toList, new Document(session.create_id(), nodes))
+    }
+  }
 }