src/Pure/Isar/outer_syntax.scala

more explicit Line_Nesting;

/*  Title:      Pure/Isar/outer_syntax.scala
    Author:     Makarius

Isabelle/Isar outer syntax.
*/

package isabelle


import scala.util.parsing.input.{Reader, CharSequenceReader}
import scala.collection.mutable


object Outer_Syntax
{
  def quote_string(str: String): String =
  {
    val result = new StringBuilder(str.length + 10)
    result += '"'
    for (s <- Symbol.iterator(str)) {
      if (s.length == 1) {
        val c = s(0)
        if (c < 32 && c != YXML.X && c != YXML.Y || c == '\\' || c == '"') {
          result += '\\'
          if (c < 10) result += '0'
          if (c < 100) result += '0'
          result ++= (c.asInstanceOf[Int].toString)
        }
        else result += c
      }
      else result ++= s
    }
    result += '"'
    result.toString
  }

  val empty: Outer_Syntax = new Outer_Syntax()

  def init(): Outer_Syntax = new Outer_Syntax(completion = Completion.init())


  /* line nesting */

  object Line_Nesting
  {
    val init = Line_Nesting(0, 0)
  }

  sealed case class Line_Nesting(depth_before: Int, depth: Int)
}

final class Outer_Syntax private(
  keywords: Map[String, (String, List[String])] = Map.empty,
  lexicon: Scan.Lexicon = Scan.Lexicon.empty,
  val completion: Completion = Completion.empty,
  val language_context: Completion.Language_Context = Completion.Language_Context.outer,
  val has_tokens: Boolean = true) extends Prover.Syntax
{
  override def toString: String =
    (for ((name, (kind, files)) <- keywords) yield {
      if (kind == Keyword.MINOR) quote(name)
      else
        quote(name) + " :: " + quote(kind) +
        (if (files.isEmpty) "" else " (" + commas_quote(files) + ")")
    }).toList.sorted.mkString("keywords\n  ", " and\n  ", "")


  /* keyword kind */

  def keyword_kind_files(name: String): Option[(String, List[String])] = keywords.get(name)
  def keyword_kind(name: String): Option[String] = keyword_kind_files(name).map(_._1)

  def is_command(name: String): Boolean =
    keyword_kind(name) match {
      case Some(kind) => kind != Keyword.MINOR
      case None => false
    }

  def command_kind(token: Token, pred: String => Boolean): Boolean =
    token.is_command && is_command(token.source) &&
      pred(keyword_kind(token.source).get)


  /* load commands */

  def load_command(name: String): Option[List[String]] =
    keywords.get(name) match {
      case Some((Keyword.THY_LOAD, exts)) => Some(exts)
      case _ => None
    }

  val load_commands: List[(String, List[String])] =
    (for ((name, (Keyword.THY_LOAD, files)) <- keywords.iterator) yield (name, files)).toList

  def load_commands_in(text: String): Boolean =
    load_commands.exists({ case (cmd, _) => text.containsSlice(cmd) })


  /* add keywords */

  def + (name: String, kind: (String, List[String]), replace: Option[String]): Outer_Syntax =
  {
    val keywords1 = keywords + (name -> kind)
    val lexicon1 = lexicon + name
    val completion1 =
      if (Keyword.control(kind._1) || replace == Some("")) completion
      else completion + (name, replace getOrElse name)
    new Outer_Syntax(keywords1, lexicon1, completion1, language_context, true)
  }

  def + (name: String, kind: (String, List[String])): Outer_Syntax =
    this + (name, kind, Some(name))
  def + (name: String, kind: String): Outer_Syntax =
    this + (name, (kind, Nil), Some(name))
  def + (name: String, replace: Option[String]): Outer_Syntax =
    this + (name, (Keyword.MINOR, Nil), replace)
  def + (name: String): Outer_Syntax = this + (name, None)

  def add_keywords(keywords: Thy_Header.Keywords): Outer_Syntax =
    (this /: keywords) {
      case (syntax, (name, Some((kind, _)), replace)) =>
        syntax +
          (Symbol.decode(name), kind, replace) +
          (Symbol.encode(name), kind, replace)
      case (syntax, (name, None, replace)) =>
        syntax +
          (Symbol.decode(name), replace) +
          (Symbol.encode(name), replace)
    }


  /* document headings */

  def heading_level(name: String): Option[Int] =
  {
    keyword_kind(name) match {
      case _ if name == "header" => Some(0)
      case Some(Keyword.THY_HEADING1) => Some(1)
      case Some(Keyword.THY_HEADING2) | Some(Keyword.PRF_HEADING2) => Some(2)
      case Some(Keyword.THY_HEADING3) | Some(Keyword.PRF_HEADING3) => Some(3)
      case Some(Keyword.THY_HEADING4) | Some(Keyword.PRF_HEADING4) => Some(4)
      case Some(kind) if Keyword.theory(kind) => Some(5)
      case _ => None
    }
  }

  def heading_level(command: Command): Option[Int] =
    heading_level(command.name)


  /* line nesting */

  def line_nesting(tokens: List[Token], depth: Int): Outer_Syntax.Line_Nesting =
  {
    val depth1 =
      if (tokens.exists(tok => command_kind(tok, Keyword.theory))) 0
      else depth
    val depth2 =
      (depth /: tokens) { case (d, tok) =>
        if (command_kind(tok, Keyword.theory_goal)) 1
        else if (command_kind(tok, Keyword.theory)) 0
        else if (command_kind(tok, Keyword.proof_goal)) d + 1
        else if (command_kind(tok, Keyword.qed)) d - 1
        else if (command_kind(tok, Keyword.qed_global)) 0
        else d
      }
    Outer_Syntax.Line_Nesting(depth1, depth2)
  }


  /* token language */

  def scan(input: CharSequence): List[Token] =
  {
    val in: Reader[Char] = new CharSequenceReader(input)
    Token.Parsers.parseAll(
        Token.Parsers.rep(Token.Parsers.token(lexicon, is_command)), in) match {
      case Token.Parsers.Success(tokens, _) => tokens
      case _ => error("Unexpected failure of tokenizing input:\n" + input.toString)
    }
  }

  def scan_line(input: CharSequence, context: Scan.Line_Context, nesting: Outer_Syntax.Line_Nesting)
    : (List[Token], Scan.Line_Context, Outer_Syntax.Line_Nesting) =
  {
    var in: Reader[Char] = new CharSequenceReader(input)
    val toks = new mutable.ListBuffer[Token]
    var ctxt = context
    while (!in.atEnd) {
      Token.Parsers.parse(Token.Parsers.token_line(lexicon, is_command, ctxt), in) match {
        case Token.Parsers.Success((x, c), rest) => { toks += x; ctxt = c; in = rest }
        case Token.Parsers.NoSuccess(_, rest) =>
          error("Unexpected failure of tokenizing input:\n" + rest.source.toString)
      }
    }
    val tokens = toks.toList
    (tokens, ctxt, line_nesting(tokens, nesting.depth))
  }


  /* parse_spans */

  def parse_spans(toks: List[Token]): List[Command_Span.Span] =
  {
    val result = new mutable.ListBuffer[Command_Span.Span]
    val content = new mutable.ListBuffer[Token]
    val improper = new mutable.ListBuffer[Token]

    def ship(span: List[Token])
    {
      val kind =
        if (!span.isEmpty && span.head.is_command && !span.exists(_.is_error)) {
          val name = span.head.source
          val pos = Position.Range(Text.Range(0, Symbol.iterator(name).length) + 1)
          Command_Span.Command_Span(name, pos)
        }
        else if (span.forall(_.is_improper)) Command_Span.Ignored_Span
        else Command_Span.Malformed_Span
      result += Command_Span.Span(kind, span)
    }

    def flush()
    {
      if (!content.isEmpty) { ship(content.toList); content.clear }
      if (!improper.isEmpty) { ship(improper.toList); improper.clear }
    }

    for (tok <- toks) {
      if (tok.is_command) { flush(); content += tok }
      else if (tok.is_improper) improper += tok
      else { content ++= improper; improper.clear; content += tok }
    }
    flush()

    result.toList
  }

  def parse_spans(input: CharSequence): List[Command_Span.Span] =
    parse_spans(scan(input))


  /* language context */

  def set_language_context(context: Completion.Language_Context): Outer_Syntax =
    new Outer_Syntax(keywords, lexicon, completion, context, has_tokens)

  def no_tokens: Outer_Syntax =
  {
    require(keywords.isEmpty && lexicon.isEmpty)
    new Outer_Syntax(
      completion = completion,
      language_context = language_context,
      has_tokens = false)
  }
}