static SliceNode filterTree(
SliceNode oldRoot,
NullableFunction<SliceNode, SliceNode> filter,
PairProcessor<SliceNode, List<SliceNode>> postProcessor) {
SliceNode filtered = filter.fun(oldRoot);
if (filtered == null) return null;
List<SliceNode> childrenFiltered = new ArrayList<SliceNode>();
if (oldRoot.myCachedChildren != null) {
for (SliceNode child : oldRoot.myCachedChildren) {
SliceNode childFiltered = filterTree(child, filter, postProcessor);
if (childFiltered != null) {
childrenFiltered.add(childFiltered);
}
}
}
boolean success = postProcessor == null || postProcessor.process(filtered, childrenFiltered);
if (!success) return null;
filtered.myCachedChildren = new ArrayList<SliceNode>(childrenFiltered);
return filtered;
}
