move getChildren() from Tree into Trees

runtime/Java/src/org/antlr/v4/runtime/ParserRuleContext.java

@@ -193,11 +193,6 @@ public class ParserRuleContext extends RuleContext {
 		return null;
 	}
 
-	@Override
-	public List<ParseTree> getChildren() {
-		return children;
-	}
-
 	public TerminalNode getToken(int ttype, int i) {
 		if ( children==null || i < 0 || i >= children.size() ) {
 			return null;

runtime/Java/src/org/antlr/v4/runtime/RuleContext.java

@@ -150,11 +150,6 @@ public class RuleContext implements RuleNode {
 		return 0;
 	}
 
-	@Override
-	public List<ParseTree> getChildren() {
-		return null;
-	}
-
 	@Override
 	public <T> T accept(ParseTreeVisitor<? extends T> visitor) { return visitor.visitChildren(this); }
 

runtime/Java/src/org/antlr/v4/runtime/tree/TerminalNodeImpl.java

@@ -65,11 +65,6 @@ public class TerminalNodeImpl implements TerminalNode {
 	@Override
 	public int getChildCount() { return 0; }
 
-	@Override
-	public List<ParseTree> getChildren() {
-		return null;
-	}
-
 	@Override
 	public <T> T accept(ParseTreeVisitor<? extends T> visitor) {
 		return visitor.visitTerminal(this);

runtime/Java/src/org/antlr/v4/runtime/tree/Tree.java

@@ -62,9 +62,6 @@ public interface Tree {
 	 */
 	int getChildCount();
 
-	/** Return ordered list of all children of this node */
-	List<? extends Tree> getChildren();
-
 	/** Print out a whole tree, not just a node, in LISP format
 	 *  {@code (root child1 .. childN)}. Print just a node if this is a leaf.
 	 */

runtime/Java/src/org/antlr/v4/runtime/tree/Trees.java

@@ -154,6 +154,16 @@ public class Trees {
 		return t.getPayload().toString();
 	}
 
+
+	/** Return ordered list of all children of this node */
+	public static List<Tree> getChildren(Tree t) {
+		List<Tree> kids = new ArrayList<Tree>();
+		for (int i=0; i<t.getChildCount(); i++) {
+			kids.add(t.getChild(i));
+		}
+		return kids;
+	}
+
 	/** Return a list of all ancestors of this node.  The first node of
 	 *  list is the root and the last is the parent of this node.
 	 */

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

@@ -3,6 +3,7 @@ package org.antlr.v4.runtime.tree.xpath;
 import org.antlr.v4.runtime.ParserRuleContext;
 import org.antlr.v4.runtime.tree.ParseTree;
 import org.antlr.v4.runtime.tree.Tree;
+import org.antlr.v4.runtime.tree.Trees;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -19,7 +20,7 @@ public class XPathRuleElement extends XPathElement {
 	public Collection<ParseTree> evaluate(ParseTree t) {
 				// return all children of t that match nodeName
 		List<ParseTree> nodes = new ArrayList<ParseTree>();
-		for (Tree c : t.getChildren()) {
+		for (Tree c : Trees.getChildren(t)) {
 			if ( c instanceof ParserRuleContext ) {
 				ParserRuleContext ctx = (ParserRuleContext)c;
 				if ( (ctx.getRuleIndex() == ruleIndex && !invert) ||

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

@@ -3,6 +3,7 @@ package org.antlr.v4.runtime.tree.xpath;
 import org.antlr.v4.runtime.tree.ParseTree;
 import org.antlr.v4.runtime.tree.TerminalNode;
 import org.antlr.v4.runtime.tree.Tree;
+import org.antlr.v4.runtime.tree.Trees;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -19,7 +20,7 @@ public class XPathTokenElement extends XPathElement {
 	public Collection<ParseTree> evaluate(ParseTree t) {
 		// return all children of t that match nodeName
 		List<ParseTree> nodes = new ArrayList<ParseTree>();
-		for (Tree c : t.getChildren()) {
+		for (Tree c : Trees.getChildren(t)) {
 			if ( c instanceof TerminalNode ) {
 				TerminalNode tnode = (TerminalNode)c;
 				if ( (tnode.getSymbol().getType() == tokenType && !invert) ||

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

@@ -1,9 +1,12 @@
 package org.antlr.v4.runtime.tree.xpath;
 
 import org.antlr.v4.runtime.tree.ParseTree;
+import org.antlr.v4.runtime.tree.Tree;
+import org.antlr.v4.runtime.tree.Trees;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 
 public class XPathWildcardElement extends XPathElement {
@@ -14,6 +17,10 @@ public class XPathWildcardElement extends XPathElement {
 	@Override
 	public Collection<ParseTree> evaluate(final ParseTree t) {
 		if ( invert ) return new ArrayList<ParseTree>(); // !* is weird but valid (empty)
-		return new ArrayList<ParseTree>() {{addAll((List<ParseTree>)t.getChildren());}};
+		List<ParseTree> kids = new ArrayList<ParseTree>();
+		for (Tree c : Trees.getChildren(t)) {
+			kids.add((ParseTree)c);
+		}
+		return kids;
 	}
 }