/* Title: Pure/General/comment.scala
Author: Makarius
Formal comments.
*/
package isabelle
object Comment {
object Kind extends Enumeration {
val COMMENT = Value("formal comment")
val CANCEL = Value("canceled text")
val LATEX = Value("embedded LaTeX")
val MARKER = Value("document marker")
}
lazy val symbols: Set[Symbol.Symbol] =
Set(Symbol.comment, Symbol.comment_decoded,
Symbol.cancel, Symbol.cancel_decoded,
Symbol.latex, Symbol.latex_decoded,
Symbol.marker, Symbol.marker_decoded)
lazy val symbols_blanks: Set[Symbol.Symbol] =
Set(Symbol.comment, Symbol.comment_decoded)
def content(source: String): String = {
def err(): Nothing = error("Malformed formal comment: " + quote(source))
Symbol.explode(source) match {
case sym :: rest if symbols_blanks(sym) =>
val body = if (symbols_blanks(sym)) rest.dropWhile(Symbol.is_blank) else rest
try { Scan.Parsers.cartouche_content(body.mkString) }
catch { case ERROR(_) => err() }
case _ => err()
}
}
trait Parsers extends Scan.Parsers {
def comment_prefix: Parser[String] =
one(symbols_blanks) ~ many(Symbol.is_blank) ^^ { case a ~ b => a + b.mkString } |
one(symbols)
def comment_cartouche: Parser[String] =
comment_prefix ~ cartouche ^^ { case a ~ b => a + b }
def comment_cartouche_line(ctxt: Scan.Line_Context): Parser[(String, Scan.Line_Context)] = {
def cartouche_context(d: Int): Scan.Line_Context =
if (d == 0) Scan.Finished else Scan.Cartouche_Comment(d)
ctxt match {
case Scan.Finished =>
comment_prefix ~ opt(cartouche_depth(0)) ^^ {
case a ~ None => (a, Scan.Comment_Prefix(a))
case a ~ Some((c, d)) => (a + c, cartouche_context(d)) }
case Scan.Comment_Prefix(a) if symbols_blanks(a) =>
many1(Symbol.is_blank) ~ opt(cartouche_depth(0)) ^^ {
case b ~ None => (b.mkString, Scan.Comment_Prefix(a))
case b ~ Some((c, d)) => (b.mkString + c, cartouche_context(d)) } |
cartouche_depth(0) ^^ { case (c, d) => (c, cartouche_context(d)) }
case Scan.Comment_Prefix(_) =>
cartouche_depth(0) ^^ { case (c, d) => (c, cartouche_context(d)) }
case Scan.Cartouche_Comment(depth) =>
cartouche_depth(depth) ^^ { case (c, d) => (c, cartouche_context(d)) }
case _ => failure("")
}
}
}
}