markup bad YXML as malformed;
removed unused XML.document;
removed unused markup;
/* Title: Pure/General/xml.scala
Author: Makarius
Simple XML tree values.
*/
package isabelle
import java.util.WeakHashMap
import java.lang.ref.WeakReference
import javax.xml.parsers.DocumentBuilderFactory
import org.w3c.dom.{Node, Document}
object XML
{
/* datatype representation */
type Attributes = List[(String, String)]
sealed abstract class Tree {
override def toString = {
val s = new StringBuilder
append_tree(this, s)
s.toString
}
}
case class Elem(name: String, attributes: Attributes, body: List[Tree]) extends Tree
case class Text(content: String) extends Tree
def elem(name: String, body: List[Tree]) = Elem(name, Nil, body)
def elem(name: String) = Elem(name, Nil, Nil)
/* string representation */
private def append_text(text: String, s: StringBuilder) {
if (text == null) s ++ text
else {
for (c <- text.elements) c match {
case '<' => s ++ "<"
case '>' => s ++ ">"
case '&' => s ++ "&"
case '"' => s ++ """
case '\'' => s ++ "'"
case _ => s + c
}
}
}
private def append_elem(name: String, atts: Attributes, s: StringBuilder) {
s ++ name
for ((a, x) <- atts) {
s ++ " "; s ++ a; s ++ "=\""; append_text(x, s); s ++ "\""
}
}
private def append_tree(tree: Tree, s: StringBuilder) {
tree match {
case Elem(name, atts, Nil) =>
s ++ "<"; append_elem(name, atts, s); s ++ "/>"
case Elem(name, atts, ts) =>
s ++ "<"; append_elem(name, atts, s); s ++ ">"
for (t <- ts) append_tree(t, s)
s ++ "</"; s ++ name; s ++ ">"
case Text(text) => append_text(text, s)
}
}
/* iterate over content */
private type State = Option[(String, List[Tree])]
private def get_next(tree: Tree): State = tree match {
case Elem(_, _, body) => get_nexts(body)
case Text(content) => Some(content, Nil)
}
private def get_nexts(trees: List[Tree]): State = trees match {
case Nil => None
case t :: ts => get_next(t) match {
case None => get_nexts(ts)
case Some((s, r)) => Some((s, r ++ ts))
}
}
def content(tree: Tree) = new Iterator[String] {
private var state = get_next(tree)
def hasNext() = state.isDefined
def next() = state match {
case Some((s, rest)) => { state = get_nexts(rest); s }
case None => throw new NoSuchElementException("next on empty iterator")
}
}
/* cache for partial sharing -- NOT THREAD SAFE */
class Cache(initial_size: Int)
{
private val table = new WeakHashMap[Any, WeakReference[Any]](initial_size)
private def lookup[A](x: A): Option[A] =
{
val ref = table.get(x)
if (ref == null) None
else {
val y = ref.asInstanceOf[WeakReference[A]].get
if (y == null) None
else Some(y)
}
}
private def store[A](x: A): A =
{
table.put(x, new WeakReference[Any](x))
x
}
def cache_string(x: String): String =
lookup(x) match {
case Some(y) => y
case None => store(x)
}
def cache_props(x: List[(String, String)]): List[(String, String)] =
lookup(x) match {
case Some(y) => y
case None => store(x.map(p => (cache_string(p._1), cache_string(p._2))))
}
def cache_tree(x: XML.Tree): XML.Tree =
lookup(x) match {
case Some(y) => y
case None =>
x match {
case XML.Elem(name, props, body) =>
store(XML.Elem(cache_string(name), cache_props(props), cache_trees(body)))
case XML.Text(text) => XML.Text(cache_string(text))
}
}
def cache_trees(x: List[XML.Tree]): List[XML.Tree] =
lookup(x) match {
case Some(y) => y
case None => x.map(cache_tree(_))
}
}
/* document object model (W3C DOM) */
def get_data(node: Node): Option[XML.Tree] =
node.getUserData(Markup.DATA) match {
case tree: XML.Tree => Some(tree)
case _ => None
}
def document_node(doc: Document, tree: Tree): Node =
{
def DOM(tr: Tree): Node = tr match {
case Elem(Markup.DATA, Nil, List(data, t)) =>
val node = DOM(t)
node.setUserData(Markup.DATA, data, null)
node
case Elem(name, atts, ts) =>
if (name == Markup.DATA)
error("Malformed data element: " + tr.toString)
val node = doc.createElement(name)
for ((name, value) <- atts) node.setAttribute(name, value)
for (t <- ts) node.appendChild(DOM(t))
node
case Text(txt) => doc.createTextNode(txt)
}
DOM(tree)
}
}