scala.xml.dtd.Scanner.scala Maven / Gradle / Ivy
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2002-2013, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala
package xml
package dtd
/**
* Scanner for regexps (content models in DTD element declarations)
* todo: cleanup
*/
class Scanner extends Tokens with parsing.TokenTests {
final val ENDCH = '\u0000'
var token: Int = END
var value: String = _
private var it: Iterator[Char] = null
private var c: Char = 'z'
/** initializes the scanner on input s */
final def initScanner(s: String) {
value = ""
it = (s).iterator
token = 1 + END
next()
nextToken()
}
/** scans the next token */
final def nextToken() {
if (token != END) token = readToken
}
// todo: see XML specification... probably isLetter,isDigit is fine
final def isIdentChar = (('a' <= c && c <= 'z')
|| ('A' <= c && c <= 'Z'))
final def next() = if (it.hasNext) c = it.next() else c = ENDCH
final def acc(d: Char) {
if (c == d) next() else scala.sys.error("expected '" + d + "' found '" + c + "' !")
}
final def accS(ds: Seq[Char]) { ds foreach acc }
final def readToken: Int =
if (isSpace(c)) {
while (isSpace(c)) c = it.next()
S
} else c match {
case '(' =>
next(); LPAREN
case ')' =>
next(); RPAREN
case ',' =>
next(); COMMA
case '*' =>
next(); STAR
case '+' =>
next(); PLUS
case '?' =>
next(); OPT
case '|' =>
next(); CHOICE
case '#' =>
next(); accS("PCDATA"); TOKEN_PCDATA
case ENDCH => END
case _ =>
if (isNameStart(c)) name; // NAME
else scala.sys.error("unexpected character:" + c)
}
final def name = {
val sb = new StringBuilder()
do { sb.append(c); next() } while (isNameChar(c))
value = sb.toString()
NAME
}
}