working on xpath

.gitignore

@@ -27,4 +27,4 @@ nbactions*.xml
 *.hprof
 
 # Playground
-/tool/playground/
+#/tool/playground/

runtime/Java/src/org/antlr/v4/runtime/tree/xpath/XPath.java

@@ -2,7 +2,12 @@
 
 import org.antlr.v4.runtime.tree.ParseTree;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /** Represent a subset of XPath paths for use in identifying nodes in
  *  parse trees.
@@ -14,27 +19,54 @@
  *  ID					all IDs anywhere
  *  /ID					an ID node if at root
  *  /classdef/field		all field children of classdef at root.
- *  //ID				all IDs anywhere (same as ID)
+ *  //ID				INVALID (same as ID)
  *  classdef//funcdef	all funcs under classdef somewhere
  *  classdef/*			all children of classdefs anywhere in tree
  *
  *  The "root" is relative to the node passed to evaluate().
  */
 public class XPath {
-
 	public static final String WILDCARD = "*"; // word not operator/separator
 
 	protected String path;
+	protected XPathElement[] elements;
 
 	public XPath(String path) {
 		this.path = path;
+		elements = split(path);
+	}
+
+	public XPathElement[] split(String path) {
+		Pattern pattern = Pattern.compile("//|/|\\w+|\\*");
+		Matcher matcher = pattern.matcher(path);
+		System.out.println("path="+path);
+		List<String> pathStrings = new ArrayList<String>();
+		while (matcher.find()) {
+			pathStrings.add(matcher.group());
+		}
+		List<XPathElement> elements = new ArrayList<XPathElement>();
+		for (String el : pathStrings) {
+		System.out.println("\t"+ el);
+			if ( el.equals("/") ) {
+
+			}
+			else if ( el.equals("//") ) {
+
+			}
+			else if ( el.equals("*") ) {
+
+			}
+			else {
+				elements.add(new XPathNodeElement(el));
+			}
+		}
+		return elements.toArray(new XPathElement[0]);
 	}
 
 	// following java xpath like methods; not sure it's best way
-	/** Return a list of all nodes starting at t that satisfy the path.
-	 *
+	/** Return a list of all nodes starting at t as root that satisfy the path.
 	 */
-	Collection<? extends ParseTree> evaluate(ParseTree t) {
+	public Collection<? extends ParseTree> evaluate(ParseTree t) {
 		return null;
 	}
 }

runtime/Java/src/org/antlr/v4/runtime/tree/xpath/XPathAnywhereElement.java

@@ -0,0 +1,8 @@
+package org.antlr.v4.runtime.tree.xpath;
+
+/** Either ID at start of path or ...//ID in middle of path */
+public class XPathAnywhereElement extends XPathElement {
+	public XPathAnywhereElement(String nodeName) {
+		super(nodeName);
+	}
+}

runtime/Java/src/org/antlr/v4/runtime/tree/xpath/XPathElement.java

@@ -1,14 +1,12 @@
 package org.antlr.v4.runtime.tree.xpath;
 
-public class XPathElement {
-	public XPathOperator op;
+public abstract class XPathElement {
 	public String nodeName;
 
-	/** Construct element like /ID or //ID or ID or "/*" etc...
+	/** Construct element like /ID or or ID or "/*" etc...
 	 *  op is null if just node
 	 */
-	public XPathElement(XPathOperator op, String nodeName) {
+	public XPathElement(String nodeName) {
 		this.nodeName = nodeName;
-		this.op = op;
 	}
 }

runtime/Java/src/org/antlr/v4/runtime/tree/xpath/XPathNodeElement.java

@@ -0,0 +1,7 @@
+package org.antlr.v4.runtime.tree.xpath;
+
+public class XPathNodeElement extends XPathElement {
+	public XPathNodeElement(String nodeName) {
+		super(nodeName);
+	}
+}

runtime/Java/src/org/antlr/v4/runtime/tree/xpath/XPathRootedElement.java

@@ -0,0 +1,7 @@
+package org.antlr.v4.runtime.tree.xpath;
+
+public class XPathRootedElement extends XPathElement {
+	public XPathRootedElement(String nodeName) {
+		super(nodeName);
+	}
+}

tool/playground/TestXPath.java

@@ -0,0 +1,31 @@
+import org.antlr.v4.runtime.ANTLRFileStream;
+import org.antlr.v4.runtime.CharStream;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.ParserRuleContext;
+import org.antlr.v4.runtime.tree.xpath.XPath;
+
+import java.io.IOException;
+
+public class TestXPath {
+	public static void main(String[] args) throws IOException {
+		CharStream input = new ANTLRFileStream("TestXPath.java");
+		JavaLexer lex = new JavaLexer(input);
+		CommonTokenStream tokens = new CommonTokenStream(lex);
+		JavaParser parser = new JavaParser(tokens);
+
+		parser.setBuildParseTree(true);
+		ParserRuleContext tree = parser.compilationUnit();
+		System.out.println(tree.toStringTree(parser));
+
+		XPath p = new XPath("ID");
+		p.evaluate(tree);
+		new XPath("A/B");
+		new XPath("/A/B");
+		new XPath("A//B");
+		new XPath("A/*");
+		new XPath("*");
+		new XPath("*/A");
+		new XPath("A/*/B");
+	}
+}
+