src/Pure/General/position.scala

clarified exception;

/*  Title:      Pure/General/position.scala
    Author:     Makarius

Position properties.
*/

package isabelle


import java.io.{File => JFile}


object Position
{
  type T = Properties.T

  val none: T = Nil

  val Line = new Properties.Int(Markup.LINE)
  val Offset = new Properties.Int(Markup.OFFSET)
  val End_Offset = new Properties.Int(Markup.END_OFFSET)
  val File = new Properties.String(Markup.FILE)
  val Id = new Properties.Long(Markup.ID)
  val Id_String = new Properties.String(Markup.ID)

  val Def_Line = new Properties.Int(Markup.DEF_LINE)
  val Def_Offset = new Properties.Int(Markup.DEF_OFFSET)
  val Def_End_Offset = new Properties.Int(Markup.DEF_END_OFFSET)
  val Def_File = new Properties.String(Markup.DEF_FILE)
  val Def_Id = new Properties.Long(Markup.DEF_ID)

  object Line_File
  {
    def apply(line: Int, file: String): T =
      (if (line > 0) Line(line) else Nil) :::
      (if (file != "") File(file) else Nil)

    def unapply(pos: T): Option[(Int, String)] =
      (pos, pos) match {
        case (Line(i), File(name)) => Some((i, name))
        case (_, File(name)) => Some((1, name))
        case _ => None
      }
  }

  object Def_Line_File
  {
    def unapply(pos: T): Option[(Int, String)] =
      (pos, pos) match {
        case (Def_Line(i), Def_File(name)) => Some((i, name))
        case (_, Def_File(name)) => Some((1, name))
        case _ => None
      }
  }

  object Range
  {
    def apply(range: Symbol.Range): T = Offset(range.start) ::: End_Offset(range.stop)
    def unapply(pos: T): Option[Symbol.Range] =
      (pos, pos) match {
        case (Offset(start), End_Offset(stop)) if start <= stop => Some(Text.Range(start, stop))
        case (Offset(start), _) => Some(Text.Range(start, start + 1))
        case _ => None
      }
  }

  object Item_Id
  {
    def unapply(pos: T): Option[(Long, Symbol.Range)] =
      pos match {
        case Id(id) =>
          val offset = Offset.unapply(pos) getOrElse 0
          val end_offset = End_Offset.unapply(pos) getOrElse (offset + 1)
          Some((id, Text.Range(offset, end_offset)))
        case _ => None
      }
  }

  object Item_Def_Id
  {
    def unapply(pos: T): Option[(Long, Symbol.Range)] =
      pos match {
        case Def_Id(id) =>
          val offset = Def_Offset.unapply(pos) getOrElse 0
          val end_offset = Def_End_Offset.unapply(pos) getOrElse (offset + 1)
          Some((id, Text.Range(offset, end_offset)))
        case _ => None
      }
  }

  object Item_File
  {
    def unapply(pos: T): Option[(String, Int, Symbol.Range)] =
      pos match {
        case Line_File(line, name) =>
          val offset = Offset.unapply(pos) getOrElse 0
          val end_offset = End_Offset.unapply(pos) getOrElse (offset + 1)
          Some((name, line, Text.Range(offset, end_offset)))
        case _ => None
      }
  }

  object Item_Def_File
  {
    def unapply(pos: T): Option[(String, Int, Symbol.Range)] =
      pos match {
        case Def_Line_File(line, name) =>
          val offset = Def_Offset.unapply(pos) getOrElse 0
          val end_offset = Def_End_Offset.unapply(pos) getOrElse (offset + 1)
          Some((name, line, Text.Range(offset, end_offset)))
        case _ => None
      }
  }

  object Identified
  {
    def unapply(pos: T): Option[(Long, Symbol.Text_Chunk.Name)] =
      pos match {
        case Id(id) =>
          val chunk_name =
            pos match {
              case File(name) => Symbol.Text_Chunk.File(name)
              case _ => Symbol.Text_Chunk.Default
            }
          Some((id, chunk_name))
        case _ => None
      }
  }

  def purge(props: T): T = props.filterNot(p => Markup.POSITION_PROPERTIES(p._1))


  /* here: user output */

  def here(props: T, delimited: Boolean = true): String =
  {
    val pos = props.filter(p => Markup.POSITION_PROPERTIES(p._1))
    if (pos.isEmpty) ""
    else {
      val s0 =
        (Line.unapply(pos), File.unapply(pos)) match {
          case (Some(i), None) => "line " + i.toString
          case (Some(i), Some(name)) => "line " + i.toString + " of " + quote(name)
          case (None, Some(name)) => "file " + quote(name)
          case _ => ""
        }
      val s = if (s0 == "") s0 else if (delimited) " (" + s0 + ")" else s0
      Markup(Markup.POSITION, pos).markup(s)
    }
  }


  /* JSON representation */

  object JSON
  {
    def apply(pos: T): isabelle.JSON.Object.T =
      isabelle.JSON.Object.empty ++
        Line.unapply(pos).map(Line.name -> _) ++
        Offset.unapply(pos).map(Offset.name -> _) ++
        End_Offset.unapply(pos).map(End_Offset.name -> _) ++
        File.unapply(pos).map(File.name -> _) ++
        Id.unapply(pos).map(Id.name -> _)

    def unapply(json: isabelle.JSON.T): Option[T] =
      for {
        line <- isabelle.JSON.int_default(json, Line.name)
        offset <- isabelle.JSON.int_default(json, Offset.name)
        end_offset <- isabelle.JSON.int_default(json, End_Offset.name)
        file <- isabelle.JSON.string_default(json, File.name)
        id <- isabelle.JSON.long_default(json, Id.name)
      }
      yield {
        def defined(name: String): Boolean = isabelle.JSON.value(json, name).isDefined
        (if (defined(Line.name)) Line(line) else Nil) :::
        (if (defined(Offset.name)) Offset(offset) else Nil) :::
        (if (defined(End_Offset.name)) End_Offset(end_offset) else Nil) :::
        (if (defined(File.name)) File(file) else Nil) :::
        (if (defined(Id.name)) Id(id) else Nil)
      }
  }
}