From d6963262b4a68577925b1281d246e30e3265e97a Mon Sep 17 00:00:00 2001
From: buraq <buraq@epfl.ch>
Date: Mon, 9 Feb 2004 18:07:31 +0000
Subject: projections on XML ! preserving document order !

---
 sources/scala/xml/Node.scala  | 51 ++++++++++++++++++++++++++++++++++++++-----
 test/files/run/xmlstuff.check |  8 ++++++-
 test/files/run/xmlstuff.scala |  8 +++++++
 3 files changed, 60 insertions(+), 7 deletions(-)

diff --git a/sources/scala/xml/Node.scala b/sources/scala/xml/Node.scala
index b3200fdf7d..9e052d3648 100644
--- a/sources/scala/xml/Node.scala
+++ b/sources/scala/xml/Node.scala
@@ -21,6 +21,10 @@ trait Node {
   /** the string representation of this XML node */
     def toXML: String;
 
+  /** projection function. Similar to XPath, use this./'foo to get a list
+   *  of all children of this node that are labelled with "foo".
+   *  The document order is preserved.
+   */
     def /(that:Symbol): NodeList = new NodeList({
       val iter = children.elements;
       if( "_" == that.label ) {
@@ -34,15 +38,22 @@ trait Node {
       }
     });
 
+  /** projection function. Similar to XPath, use this./#'foo to get a list
+   *  of all descendants of this node that are labelled with "foo".
+   *  Use /'_ as a wildcard.
+   *  The document order is preserved.
+   */
     def /#(that:Symbol): NodeList = new NodeList({
       var res:List[Node] = Nil;
+      var tmp:List[Node] = Nil;
       for( val x <- children.elements ) {
-        if ( x.label == that.label || "_" == that.label )  // order messed up here
-          res = x::res;
-        res =(x/#(that)).toList:::res;
-
+        if ( x.label == that.label || "_" == that.label )
+          tmp = x::tmp;
+        tmp = tmp:::(x/#(that)).toList;
+        res = res:::tmp;
+        tmp = Nil
       }
-      res.reverse
+      res;
     });
 
 }
@@ -51,6 +62,10 @@ trait Node {
 class NodeList(theList:List[Node]) extends List[Node] {
   val res = theList.flatMap ( x => List.fromIterator( x.children.elements ));
 
+  /** projection function. Similar to XPath, use this./'foo to get a list
+   *  of all elements of this sequence that are labelled with "foo".
+   *  Use /'_ as a wildcard. The document order is preserved.
+   */
   def /(that:Symbol) = if( "_" == that.label ) {
     new NodeList( res )
   } else {
@@ -58,6 +73,23 @@ class NodeList(theList:List[Node]) extends List[Node] {
   }
 
 
+  /** projection function. Similar to XPath, use this./'foo to get a list
+   *  of all children of this node that are labelled with "foo"
+   *  Use /#'_ as a wildcard. The document order is preserved.
+   */
+    def /#(that:Symbol): NodeList = new NodeList(
+      if ( "_" == that.label ) {
+        this.flatMap ( x => (x/#'_).toList )
+      } else {
+        this.flatMap ( x => {
+          if( x.label == that.label )
+            x::(x/#(that)).toList;
+          else
+            (x/#(that)).toList;
+        })
+      });
+
+
   def toList:List[Node] = theList;
 
   // forwarding list methods
@@ -65,10 +97,17 @@ class NodeList(theList:List[Node]) extends List[Node] {
   def isEmpty: boolean = theList.isEmpty;
   def head: Node = theList.head;
   def tail: List[Node] = theList.tail;
+
   override def toString():String = "Node"+theList.toString();
 
   override def filter(p: Node => Boolean): NodeList =
     new NodeList( theList.filter( p ) );
 
-  // == does not work
+  override def foreach(f: Node => Unit): Unit = theList.foreach( f );
+
+  override def flatMap[b](f: Node => List[b]): List[b] = theList.flatMap( f );
+
+  override def :::[b >: Node](prefix: List[b]): List[b] = theList.:::( prefix );
+
+  //the  == method cannot be forwarded :-(
 }
diff --git a/test/files/run/xmlstuff.check b/test/files/run/xmlstuff.check
index af85d96257..4636a6f8b4 100644
--- a/test/files/run/xmlstuff.check
+++ b/test/files/run/xmlstuff.check
@@ -20,4 +20,10 @@ parsedxml2/'_/'_/'author
 NodeList()
 
 parsedxml2/#'author
-NodeList('author(Text(Dan Suciu)),'author(Text(Peter Buneman)),'author(Text(John Mitchell)))
+NodeList('author(Text(Peter Buneman)),'author(Text(Dan Suciu)),'author(Text(John Mitchell)))
+
+new NodeList(List(parsedxml2))/#'_
+NodeList('book('author(Text(Peter Buneman)),'author(Text(Dan Suciu)),'title(Text(Data on ze web))),'author(Text(Peter Buneman)),Text(Peter Buneman),'author(Text(Dan Suciu)),Text(Dan Suciu),'title(Text(Data on ze web)),Text(Data on ze web),'book('author(Text(John Mitchell)),'title(Text(Foundations of Programming Languages))),'author(Text(John Mitchell)),Text(John Mitchell),'title(Text(Foundations of Programming Languages)),Text(Foundations of Programming Languages))
+
+new NodeList(List(parsedxml2))/#'title
+NodeList('title(Text(Data on ze web)),'title(Text(Foundations of Programming Languages)))
diff --git a/test/files/run/xmlstuff.scala b/test/files/run/xmlstuff.scala
index 916798e112..28f753ce90 100644
--- a/test/files/run/xmlstuff.scala
+++ b/test/files/run/xmlstuff.scala
@@ -2,6 +2,7 @@ import java.io.StringReader;
 import org.xml.sax.InputSource;
 import scala.xml.nobinding.XML;
 import scala.testing.UnitTest.assertEquals ;
+import scala.xml.NodeList;
 
 object Test with Application {
   val xmlFile1 = "<hello><world/></hello>";
@@ -39,4 +40,11 @@ object Test with Application {
   Console.println( "\nparsedxml2/#'author");
   Console.println( parsedxml2/#'author );
 
+  Console.println( "\nnew NodeList(List(parsedxml2))/#'_");
+  Console.println( new NodeList( List( parsedxml2 ))/#'_ );
+
+  Console.println( "\nnew NodeList(List(parsedxml2))/#'title");
+  Console.println( new NodeList( List( parsedxml2 ))/#'title );
+
+
 }
-- 
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