Start splitting into maven modules

1 files changed, 208 insertions, 0 deletions

diff --git a/base/src/main/java/bjc/utils/data/TopDownTransformIterator.java b/base/src/main/java/bjc/utils/data/TopDownTransformIterator.java
new file mode 100644
index 0000000..1b87e52
--- /dev/null
+++ b/base/src/main/java/bjc/utils/data/TopDownTransformIterator.java
@@ -0,0 +1,208 @@
+package bjc.utils.data;
+
+import static bjc.utils.data.TopDownTransformResult.RTRANSFORM;
+
+import java.util.Deque;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.NoSuchElementException;
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+/*
+ * FIXME something is broken in here. fix it.
+ */
+public class TopDownTransformIterator<ContainedType> implements Iterator<ITree<ContainedType>> {
+	private final Function<ContainedType, TopDownTransformResult>							picker;
+	private final BiFunction<ITree<ContainedType>, Consumer<Iterator<ITree<ContainedType>>>, ITree<ContainedType>>	transform;
+
+	private ITree<ContainedType>	preParent;
+	private ITree<ContainedType>	postParent;
+
+	private final Deque<ITree<ContainedType>>	preChildren;
+	private final Deque<ITree<ContainedType>>	postChildren;
+
+	private TopDownTransformIterator<ContainedType> curChild;
+
+	private boolean	done;
+	private boolean	initial;
+
+	private final Deque<Iterator<ITree<ContainedType>>>	toYield;
+	private Iterator<ITree<ContainedType>>			curYield;
+
+	public TopDownTransformIterator(final Function<ContainedType, TopDownTransformResult> pickr,
+			final BiFunction<ITree<ContainedType>, Consumer<Iterator<ITree<ContainedType>>>, ITree<ContainedType>> transfrm,
+			final ITree<ContainedType> tree) {
+		preParent = tree;
+
+		preChildren = new LinkedList<>();
+		postChildren = new LinkedList<>();
+		toYield = new LinkedList<>();
+
+		picker = pickr;
+		transform = transfrm;
+
+		done = false;
+		initial = true;
+	}
+
+	public void addYield(final Iterator<ITree<ContainedType>> src) {
+		if (curYield != null) {
+			toYield.push(curYield);
+		}
+
+		curYield = src;
+	}
+
+	@Override
+	public boolean hasNext() {
+		return !done;
+	}
+
+	public ITree<ContainedType> flushYields(final ITree<ContainedType> val) {
+		if (curYield != null) {
+			toYield.add(new SingleIterator<>(val));
+
+			if (curYield.hasNext())
+				return curYield.next();
+			else {
+				while (toYield.size() != 0 && !curYield.hasNext()) {
+					curYield = toYield.pop();
+				}
+
+				if (toYield.size() == 0 && !curYield.hasNext()) {
+					curYield = null;
+					return val;
+				} else return curYield.next();
+			}
+		} else return val;
+	}
+
+	@Override
+	public ITree<ContainedType> next() {
+		if (done) throw new NoSuchElementException();
+
+		if (curYield != null) {
+			if (curYield.hasNext())
+				return curYield.next();
+			else {
+				while (toYield.size() != 0 && !curYield.hasNext()) {
+					curYield = toYield.pop();
+				}
+
+				if (toYield.size() == 0 && !curYield.hasNext()) {
+					curYield = null;
+				} else return curYield.next();
+			}
+		}
+
+		if (initial) {
+			final TopDownTransformResult res = picker.apply(preParent.getHead());
+
+			switch (res) {
+			case PASSTHROUGH:
+				postParent = new Tree<>(preParent.getHead());
+
+				if (preParent.getChildrenCount() != 0) {
+					for (int i = 0; i < preParent.getChildrenCount(); i++) {
+						preChildren.add(preParent.getChild(i));
+					}
+
+					// Return whatever the first child is
+					break;
+				} else {
+					done = true;
+					return flushYields(postParent);
+				}
+			case SKIP:
+				done = true;
+				return flushYields(preParent);
+			case TRANSFORM:
+				done = true;
+				return flushYields(transform.apply(preParent, this::addYield));
+			case RTRANSFORM:
+				preParent = transform.apply(preParent, this::addYield);
+				return flushYields(preParent);
+			case PUSHDOWN:
+				if (preParent.getChildrenCount() != 0) {
+					for (int i = 0; i < preParent.getChildrenCount(); i++) {
+						preChildren.add(preParent.getChild(i));
+					}
+
+					// Return whatever the first child is
+					break;
+				} else {
+					done = true;
+					return flushYields(transform.apply(new Tree<>(preParent.getHead()),
+							this::addYield));
+				}
+			case PULLUP:
+				final ITree<ContainedType> intRes = transform.apply(preParent, this::addYield);
+
+				postParent = new Tree<>(intRes.getHead());
+
+				if (intRes.getChildrenCount() != 0) {
+					for (int i = 0; i < intRes.getChildrenCount(); i++) {
+						preChildren.add(intRes.getChild(i));
+					}
+
+					// Return whatever the first child is
+					break;
+				} else {
+					done = true;
+					return flushYields(postParent);
+				}
+			default:
+				throw new IllegalArgumentException("Unknown result type " + res);
+			}
+
+			if (res != RTRANSFORM) {
+				initial = false;
+			}
+		}
+
+		if (curChild == null || !curChild.hasNext()) {
+			if (preChildren.size() != 0) {
+				curChild = new TopDownTransformIterator<>(picker, transform, preChildren.pop());
+
+				final ITree<ContainedType> res = curChild.next();
+				System.out.println("\t\tTRACE: adding node " + res + " to children");
+				postChildren.add(res);
+
+				return flushYields(res);
+			} else {
+				ITree<ContainedType> res = null;
+
+				if (postParent == null) {
+					res = new Tree<>(preParent.getHead());
+
+					System.out.println("\t\tTRACE: adding nodes " + postChildren + " to " + res);
+
+					for (final ITree<ContainedType> child : postChildren) {
+						res.addChild(child);
+					}
+
+					// res = transform.apply(res,
+					// this::addYield);
+				} else {
+					res = postParent;
+
+					System.out.println("\t\tTRACE: adding nodes " + postChildren + " to " + res);
+					for (final ITree<ContainedType> child : postChildren) {
+						res.addChild(child);
+					}
+				}
+
+				done = true;
+				return flushYields(res);
+			}
+		} else {
+			final ITree<ContainedType> res = curChild.next();
+			System.out.println("\t\tTRACE: adding node " + res + " to children");
+			postChildren.add(res);
+
+			return flushYields(res);
+		}
+	}
+}