src/Pure/System/doc.scala

Scala version of "isabelle doc";
discontinued slightly odd / unused ">>" comments within Contents (see also b077b79061b6);

/*  Title:      Pure/System/doc.scala
    Author:     Makarius

View Isabelle documentation (see also "isabelle doc").
*/

package isabelle


import scala.util.matching.Regex


object Doc
{
  /* dirs */

  def dirs(): List[Path] =
    Path.split(Isabelle_System.getenv("ISABELLE_DOCS")).map(dir =>
      if (dir.is_dir) dir
      else error("Bad documentation directory: " + dir))


  /* contents */

  sealed abstract class Entry
  case class Section(text: String) extends Entry
  case class Doc(name: String, title: String) extends Entry

  def contents(): List[Entry] =
  {
    val Section_Entry = new Regex("""^(\S.*)\s*$""")
    val Doc_Entry = new Regex("""^\s+(\S+)\s+(.+)\s*$""")

    for {
      dir <- dirs()
      catalog = dir + Path.basic("Contents")
      if catalog.is_file
      line <- split_lines(File.read(catalog))
      entry <-
        line match {
          case Section_Entry(text) => Some(Section(text))
          case Doc_Entry(name, title) => Some(Doc(name, title))
          case _ => None
        }
    } yield entry
  }


  /* view */

  def view(name: String)
  {
    val formats = List(Isabelle_System.getenv_strict("ISABELLE_DOC_FORMAT"), "dvi")
    val docs =
      for {
        dir <- dirs()
        fmt <- formats
        doc = name + "." + fmt
        if (dir + Path.basic(doc)).is_file
      } yield (dir, doc)
    docs match {
      case (dir, doc) :: _ =>
        Isabelle_System.bash_env(dir.file, null, "\"$ISABELLE_TOOL\" display " + quote(doc) + " &")
      case Nil => error("Missing Isabelle documentation: " + quote(name))
    }
  }
}