/* Title: Pure/Isar/token.scala
Author: Makarius
Outer token syntax for Isabelle/Isar.
*/
package isabelle
object Token
{
/* tokens */
object Kind extends Enumeration
{
val COMMAND = Value("command")
val KEYWORD = Value("keyword")
val IDENT = Value("identifier")
val LONG_IDENT = Value("long identifier")
val SYM_IDENT = Value("symbolic identifier")
val VAR = Value("schematic variable")
val TYPE_IDENT = Value("type variable")
val TYPE_VAR = Value("schematic type variable")
val NAT = Value("natural number")
val FLOAT = Value("floating-point number")
val STRING = Value("string")
val ALT_STRING = Value("back-quoted string")
val VERBATIM = Value("verbatim text")
val SPACE = Value("white space")
val COMMENT = Value("comment text")
val UNPARSED = Value("unparsed input")
}
/* token reader */
class Line_Position(val line: Int) extends scala.util.parsing.input.Position
{
def column = 0
def lineContents = ""
override def toString = line.toString
def advance(token: Token): Line_Position =
{
var n = 0
for (c <- token.content if c == '\n') n += 1
if (n == 0) this else new Line_Position(line + n)
}
}
abstract class Reader extends scala.util.parsing.input.Reader[Token]
private class Token_Reader(tokens: List[Token], val pos: Line_Position) extends Reader
{
def first = tokens.head
def rest = new Token_Reader(tokens.tail, pos.advance(first))
def atEnd = tokens.isEmpty
}
def reader(tokens: List[Token]): Reader = new Token_Reader(tokens, new Line_Position(1))
}
sealed case class Token(val kind: Token.Kind.Value, val source: String)
{
def is_command: Boolean = kind == Token.Kind.COMMAND
def is_operator: Boolean = kind == Token.Kind.KEYWORD && !Symbol.is_ascii_identifier(source)
def is_delimited: Boolean =
kind == Token.Kind.STRING ||
kind == Token.Kind.ALT_STRING ||
kind == Token.Kind.VERBATIM ||
kind == Token.Kind.COMMENT
def is_name: Boolean =
kind == Token.Kind.IDENT ||
kind == Token.Kind.SYM_IDENT ||
kind == Token.Kind.STRING ||
kind == Token.Kind.NAT
def is_xname: Boolean = is_name || kind == Token.Kind.LONG_IDENT
def is_text: Boolean = is_xname || kind == Token.Kind.VERBATIM
def is_space: Boolean = kind == Token.Kind.SPACE
def is_comment: Boolean = kind == Token.Kind.COMMENT
def is_ignored: Boolean = is_space || is_comment
def is_begin: Boolean = kind == Token.Kind.KEYWORD && source == "begin"
def is_end: Boolean = kind == Token.Kind.COMMAND && source == "end"
def content: String =
if (kind == Token.Kind.STRING) Scan.Lexicon.empty.quoted_content("\"", source)
else if (kind == Token.Kind.ALT_STRING) Scan.Lexicon.empty.quoted_content("`", source)
else if (kind == Token.Kind.VERBATIM) Scan.Lexicon.empty.verbatim_content(source)
else if (kind == Token.Kind.COMMENT) Scan.Lexicon.empty.comment_content(source)
else source
def text: (String, String) =
if (kind == Token.Kind.COMMAND && source == ";") ("terminator", "")
else (kind.toString, source)
}