Deprecate childrenAccept in all modules

pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/AbstractVmNode.java

@@ -31,7 +31,7 @@ import net.sourceforge.pmd.lang.java.ast.impl.javacc.AbstractJjtreeNode;
 /**
  *
  */
-public class AbstractVmNode extends AbstractJjtreeNode<Token> implements VmNode {
+public class AbstractVmNode extends AbstractJjtreeNode<VmNode, Token> implements VmNode {
 
     /** */
     // TODO - It seems that this field is only valid when parsing, and should

pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/VmNode.java

@@ -13,9 +13,22 @@ public interface VmNode extends Node, TokenBasedNode<Token> {
      */
     Object jjtAccept(VmParserVisitor visitor, Object data);
 
+
     /**
      * Accept the visitor. *
+     *
+     * @deprecated This method is not useful, the logic for combining
+     *     children values should be present on the visitor, not the node
      */
+    @Deprecated
     Object childrenAccept(VmParserVisitor visitor, Object data);
 
+
+    @Override
+    VmNode getChild(int index);
+
+
+    @Override
+    VmNode getParent();
+
 }

pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/ast/VmParserVisitorAdapter.java

@@ -3,10 +3,24 @@ package net.sourceforge.pmd.lang.vm.ast;
 
 public class VmParserVisitorAdapter implements VmParserVisitor {
 
+
+    /** Initial value when combining values returned by children. */
+    protected Object zero() {
+        return null;
+    }
+
+    /** Merge two values of type R, used to combine values returned by children. */
+    protected Object combine(Object acc, Object r) {
+        return r;
+    }
+
     @Override
     public Object visit(final VmNode node, final Object data) {
-        node.childrenAccept(this, data);
-        return null;
+        Object returnValue = zero();
+        for (int i = 0; i < node.jjtGetNumChildren(); ++i) {
+            returnValue = combine(returnValue, node.getChild(i).jjtAccept(this, data));
+        }
+        return returnValue;
     }
 
     @Override

pmd-vm/src/main/java/net/sourceforge/pmd/lang/vm/rule/AbstractVmRule.java

@@ -82,7 +82,9 @@ public abstract class AbstractVmRule extends AbstractRule implements VmParserVis
 
     @Override
     public Object visit(final VmNode node, final Object data) {
-        node.childrenAccept(this, data);
+        for (int i = 0; i < node.jjtGetNumChildren(); ++i) {
+            node.getChild(i).jjtAccept(this, data);
+        }
         return null;
     }