Rename package root

The package root is now bjc, not io.github.bculkin2442.

1 files changed, 432 insertions, 0 deletions

diff --git a/src/main/java/bjc/data/Tree.java b/src/main/java/bjc/data/Tree.java
new file mode 100644
index 0000000..ad2d677
--- /dev/null
+++ b/src/main/java/bjc/data/Tree.java
@@ -0,0 +1,432 @@
+package bjc.data;
+
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.function.Predicate;
+import java.util.function.UnaryOperator;
+
+import bjc.funcdata.FunctionalList;
+import bjc.funcdata.IList;
+import bjc.funcdata.bst.TreeLinearizationMethod;
+
+/**
+ * A node in a homogeneous tree.
+ *
+ * @author ben
+ *
+ * @param <ContainedType>
+ *        The type contained in the tree.
+ */
+public class Tree<ContainedType> implements ITree<ContainedType> {
+	/* The data/label for this node. */
+	private ContainedType data;
+
+	/* The children of this node. */
+	private IList<ITree<ContainedType>> children;
+
+	/* Whether this node has children. */
+	/*
+	 * @NOTE Why have both this boolean and childCount? Why not just do a
+	 * childCount == 0 whenever you'd check hasChildren?
+	 * 	- Because hasChildren is set once and not reset, and really what
+	 * 		it indicates is that children has been allocated.
+	 */
+	private boolean hasChildren;
+	/* The number of children this node has. */
+	private int childCount = 0;
+
+	/* The ID of this node. */
+	private int ID;
+	/* The next ID to assign to a node. */
+	private static int nextID = 0;
+
+	/**
+	 * Create a new leaf node in a tree.
+	 */
+	public Tree() {
+		this(null);
+	}
+
+	/**
+	 * Create a new leaf node in a tree.
+	 *
+	 * @param leaf
+	 *        The data to store as a leaf node.
+	 */
+	public Tree(final ContainedType leaf) {
+		data = leaf;
+
+		hasChildren = false;
+
+		ID = nextID++;
+	}
+
+	/**
+	 * Create a new tree node with the specified children.
+	 *
+	 * @param leaf
+	 *        The data to hold in this node.
+	 *
+	 * @param childrn
+	 *        A list of children for this node.
+	 */
+	public Tree(final ContainedType leaf, final IList<ITree<ContainedType>> childrn) {
+		this(leaf);
+
+		hasChildren = true;
+
+		childCount = childrn.getSize();
+
+		children = childrn;
+	}
+
+	/**
+	 * Create a new tree node with the specified children.
+	 *
+	 * @param leaf
+	 *        The data to hold in this node.
+	 *
+	 * @param childrn
+	 *        A list of children for this node.
+	 */
+	@SafeVarargs
+	public Tree(final ContainedType leaf, final ITree<ContainedType>... childrn) {
+		this(leaf);
+
+		hasChildren = true;
+
+		childCount = 0;
+
+		children = new FunctionalList<>();
+
+		for(final ITree<ContainedType> child : childrn) {
+			children.add(child);
+
+			childCount++;
+		}
+	}
+
+	@Override
+	public void addChild(final ContainedType child) {
+		addChild(new Tree(child));
+	}
+
+	@Override
+	public void addChild(final ITree<ContainedType> child) {
+		if(hasChildren == false) {
+			hasChildren = true;
+
+			children = new FunctionalList<>();
+		}
+
+		childCount++;
+
+		children.add(child);
+	}
+
+	@Override
+	public void prependChild(final ITree<ContainedType> child) {
+		if(hasChildren == false) {
+			hasChildren = true;
+
+			children = new FunctionalList<>();
+		}
+
+		childCount++;
+
+		children.prepend(child);
+	}
+
+	@Override
+	public void doForChildren(final Consumer<ITree<ContainedType>> action) {
+		if(childCount > 0) {
+			children.forEach(action);
+		}
+	}
+
+	@Override
+	public int getChildrenCount() {
+		return childCount;
+	}
+
+	@Override
+	public int revFind(final Predicate<ITree<ContainedType>> childPred) {
+		if(childCount == 0) {
+			return -1;
+		}
+
+		for(int i = childCount - 1; i >= 0; i--) {
+			if(childPred.test(getChild(i))) return i;
+		}
+
+		return -1;
+	}
+
+	@Override
+	public void traverse(final TreeLinearizationMethod linearizationMethod, final Consumer<ContainedType> action) {
+		if(hasChildren) {
+			switch(linearizationMethod) {
+			case INORDER:
+				if(childCount != 2) {
+					final String msg = "Can only do in-order traversal for binary trees.";
+
+					throw new IllegalArgumentException(msg);
+				}
+
+				children.getByIndex(0).traverse(linearizationMethod, action);
+
+				action.accept(data);
+
+				children.getByIndex(1).traverse(linearizationMethod, action);
+				break;
+			case POSTORDER:
+				children.forEach((child) -> child.traverse(linearizationMethod, action));
+
+				action.accept(data);
+				break;
+			case PREORDER:
+				action.accept(data);
+
+				children.forEach((child) -> child.traverse(linearizationMethod, action));
+				break;
+			default:
+				break;
+
+			}
+		} else {
+			action.accept(data);
+		}
+	}
+
+	@Override
+	public <NewType, ReturnedType> ReturnedType collapse(final Function<ContainedType, NewType> leafTransform,
+			final BiFunction<ContainedType, IList<NewType>, NewType> nodeCollapser,
+			final Function<NewType, ReturnedType> resultTransformer) {
+		return resultTransformer.apply(internalCollapse(leafTransform, nodeCollapser));
+	}
+
+	@Override
+	public ITree<ContainedType> flatMapTree(final Function<ContainedType, ITree<ContainedType>> mapper) {
+		if(hasChildren) {
+			final ITree<ContainedType> flatMappedData = mapper.apply(data);
+
+			final IList<ITree<ContainedType>> mappedChildren = children
+					.map(child -> child.flatMapTree(mapper));
+
+			mappedChildren.forEach(flatMappedData::addChild);
+
+			return flatMappedData;
+		}
+
+		return mapper.apply(data);
+	}
+
+	/*
+	 * Do a collapse of this tree.
+	 *
+	 * @NOTE Why is this protected? I can't see any good reason someone'd
+	 * want to override it.
+	 */
+
+	protected <NewType> NewType internalCollapse(final Function<ContainedType, NewType> leafTransform,
+			final BiFunction<ContainedType, IList<NewType>, NewType> nodeCollapser) {
+		if(hasChildren) {
+			final IList<NewType> collapsedChildren = children.map(child -> {
+				final NewType collapsed = child.collapse(leafTransform, nodeCollapser,
+						subTreeVal -> subTreeVal);
+
+				return collapsed;
+			});
+
+			return nodeCollapser.apply(data, collapsedChildren);
+		}
+
+		return leafTransform.apply(data);
+	}
+
+	protected void internalToString(final StringBuilder builder, final int indentLevel, final boolean initial) {
+		if(!initial) {
+			for(int i = 0; i < indentLevel; i++) {
+				builder.append(">\t");
+			}
+		}
+
+		builder.append("Node #");
+		builder.append(ID);
+		builder.append(": ");
+		builder.append(data == null ? "(null)" : data.toString());
+		builder.append("\n");
+
+		if(hasChildren) {
+			children.forEach(child -> {
+				if(child instanceof Tree<?>) {
+					final Tree<ContainedType> kid = (Tree<ContainedType>) child;
+
+					kid.internalToString(builder, indentLevel + 1, false);
+				} else {
+					for(int i = 0; i < indentLevel + 1; i++) {
+						builder.append(">\t");
+					}
+
+					builder.append("Unknown node of type ");
+					builder.append(child.getClass().getName());
+					builder.append("\n");
+				}
+			});
+		}
+	}
+
+	@Override
+	public <MappedType> ITree<MappedType> rebuildTree(final Function<ContainedType, MappedType> leafTransformer,
+			final Function<ContainedType, MappedType> operatorTransformer) {
+		if(hasChildren) {
+			final IList<ITree<MappedType>> mappedChildren = children.map(child -> {
+				return child.rebuildTree(leafTransformer, operatorTransformer);
+			});
+
+			final MappedType mapData = operatorTransformer.apply(data);
+			return new Tree<>(mapData, mappedChildren);
+		}
+
+		return new Tree<>(leafTransformer.apply(data));
+	}
+
+	@Override
+	public void selectiveTransform(final Predicate<ContainedType> nodePicker,
+			final UnaryOperator<ContainedType> transformer) {
+		if(hasChildren) {
+			children.forEach(child -> child.selectiveTransform(nodePicker, transformer));
+		} else {
+			data = transformer.apply(data);
+		}
+	}
+
+	@Override
+	public ITree<ContainedType> topDownTransform(
+			final Function<ContainedType, TopDownTransformResult> transformPicker,
+			final UnaryOperator<ITree<ContainedType>> transformer) {
+		final TopDownTransformResult transformResult = transformPicker.apply(data);
+
+		switch(transformResult) {
+		case PASSTHROUGH:
+			ITree<ContainedType> result = new Tree<>(data);
+
+			if(hasChildren) {
+				children.forEach(child -> {
+					final ITree<ContainedType> kid = child.topDownTransform(transformPicker,
+							transformer);
+
+					result.addChild(kid);
+				});
+			}
+
+			return result;
+		case SKIP:
+			return this;
+		case TRANSFORM:
+			return transformer.apply(this);
+		case RTRANSFORM:
+			return transformer.apply(this).topDownTransform(transformPicker, transformer);
+		case PUSHDOWN:
+			result = new Tree<>(data);
+
+			if(hasChildren) {
+				children.forEach(child -> {
+					final ITree<ContainedType> kid = child.topDownTransform(transformPicker,
+							transformer);
+
+					result.addChild(kid);
+				});
+			}
+
+			return transformer.apply(result);
+		case PULLUP:
+			final ITree<ContainedType> intermediateResult = transformer.apply(this);
+
+			result = new Tree<>(intermediateResult.getHead());
+
+			intermediateResult.doForChildren(child -> {
+				final ITree<ContainedType> kid = child.topDownTransform(transformPicker, transformer);
+
+				result.addChild(kid);
+			});
+
+			return result;
+		default:
+			final String msg = String.format("Recieved unknown transform result type %s", transformResult);
+
+			throw new IllegalArgumentException(msg);
+		}
+	}
+
+	@Override
+	public <TransformedType> TransformedType transformChild(final int childNo,
+			final Function<ITree<ContainedType>, TransformedType> transformer) {
+		if(childNo < 0 || childNo > childCount - 1) {
+			final String msg = String.format("Child index #%d is invalid", childNo);
+
+			throw new IllegalArgumentException(msg);
+		}
+
+		final ITree<ContainedType> selectedKid = children.getByIndex(childNo);
+
+		return transformer.apply(selectedKid);
+	}
+
+	@Override
+	public <TransformedType> TransformedType transformHead(
+			final Function<ContainedType, TransformedType> transformer) {
+		return transformer.apply(data);
+	}
+
+	@Override
+	public void setHead(ContainedType dat) {
+		this.data = dat;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+
+		result = prime * result + childCount;
+		result = prime * result + (children == null ? 0 : children.hashCode());
+		result = prime * result + (data == null ? 0 : data.hashCode());
+
+		return result;
+	}
+
+	@Override
+	public String toString() {
+		final StringBuilder builder = new StringBuilder();
+
+		internalToString(builder, 1, true);
+
+		/* Delete a trailing nl. */
+		builder.deleteCharAt(builder.length() - 1);
+
+		return builder.toString();
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if(this == obj) return true;
+		if(obj == null) return false;
+		if(!(obj instanceof Tree<?>)) return false;
+
+		final Tree<?> other = (Tree<?>) obj;
+
+		if(data == null) {
+			if(other.data != null) return false;
+		} else if(!data.equals(other.data)) return false;
+
+		if(childCount != other.childCount) return false;
+
+		if(children == null) {
+			if(other.children != null) return false;
+		} else if(!children.equals(other.children)) return false;
+
+		return true;
+	}
+}