From 629b6bc7444005915983ae8d86c89c4ae215729e Mon Sep 17 00:00:00 2001
From: Ben Culkin <scorpress@gmail.com>
Date: Tue, 26 Jul 2022 20:35:01 -0400
Subject: Restructure a bit

---
 src/main/java/bjc/esodata/AbbrevTree.java | 276 ++++++++++++++++++++++++++++++
 1 file changed, 276 insertions(+)
 create mode 100644 src/main/java/bjc/esodata/AbbrevTree.java

(limited to 'src/main/java/bjc/esodata/AbbrevTree.java')

diff --git a/src/main/java/bjc/esodata/AbbrevTree.java b/src/main/java/bjc/esodata/AbbrevTree.java
new file mode 100644
index 0000000..35c44f0
--- /dev/null
+++ b/src/main/java/bjc/esodata/AbbrevTree.java
@@ -0,0 +1,276 @@
+package bjc.esodata;
+
+import java.util.*;
+
+import bjc.data.Pair;
+import bjc.data.TransformIterator;
+import bjc.funcdata.FunctionalList;
+import bjc.funcdata.ListEx;
+
+/**
+ * A labeled tree, where you can reference sub-nodes by their label as long as
+ * the reference is unambiguous.
+ *
+ * Inspired by the way that you can reference COBOL members by their name, as
+ * long as it is unambiguous. If it is ambiguous, you can instead use parent
+ * nodes to disambiguate.
+ *
+ * Additional note: The base iterator will give you all of the child nodes, but
+ * in no defined order.
+ * 
+ * @param <Label>     The label on each node
+ * @param <Contained> The type of data contained in the nodes.
+ */
+public class AbbrevTree<Label, Contained> implements Iterable<Pair<Label, Contained>> {
+	private Multimap<Label, AbbrevTree<Label, Contained>> labelledNodes;
+
+	private Map<Label, AbbrevTree<Label, Contained>> children;
+	private AbbrevTree<Label, Contained> parent;
+
+	private Contained data;
+	private Label label;
+
+	/**
+	 * Create a new empty root AbbrevTree.
+	 */
+	public AbbrevTree() {
+		labelledNodes = new Multimap<>();
+		children = new HashMap<>();
+	}
+
+	/**
+	 * Create a new occupied root AbbrevTree
+	 * 
+	 * @param label The label for this tree
+	 * @param data  The data for this tree
+	 */
+	public AbbrevTree(Label label, Contained data) {
+		this();
+
+		this.label = label;
+		this.data = data;
+	}
+
+	/**
+	 * Create a new empty child AbbrevTree.
+	 * 
+	 * @param parent The parent of this node
+	 */
+	public AbbrevTree(AbbrevTree<Label, Contained> parent) {
+		labelledNodes = new Multimap<>();
+		children = new HashMap<>();
+
+		this.parent = parent;
+	}
+
+	/**
+	 * Create a new occupied child AbbrevTree
+	 * 
+	 * @param parent The parent of this node
+	 * @param label  The label for this tree
+	 * @param data   The data for this tree
+	 */
+	public AbbrevTree(AbbrevTree<Label, Contained> parent, Label label, Contained data) {
+		this();
+
+		this.parent = parent;
+		this.label = label;
+		this.data = data;
+
+		addFromChild(label, this);
+	}
+
+	private void addFromChild(Label lbl, AbbrevTree<Label, Contained> node) {
+		labelledNodes.add(lbl, node);
+
+		if (parent != null)
+			parent.addFromChild(lbl, node);
+	}
+
+	/**
+	 * Get the data contained in this node.
+	 * 
+	 * @return The contained data.
+	 */
+	public Contained getData() {
+		return data;
+	}
+
+	/**
+	 * Set the data contained in this node.
+	 * 
+	 * @param data The new data.
+	 */
+	public void setData(Contained data) {
+		this.data = data;
+	}
+
+	/**
+	 * Get the label for this node.
+	 * 
+	 * @return The label for this node.
+	 */
+	public Label getLabel() {
+		return label;
+	}
+
+	/*
+	 * Unsupported for now. This requires some additional scaffolding.
+	 * 
+	 * Set the label for this node.
+	 * 
+	 * @param label The new label for this node.
+	 */
+	// public void setLabel(Label label) {
+	// this.label = label;
+	// }
+
+	/**
+	 * Add a child to this node
+	 * 
+	 * @param key The label for the new node
+	 * @param dat The data for the new node.
+	 * 
+	 * @return The new node
+	 */
+	public AbbrevTree<Label, Contained> add(Label key, Contained dat) {
+		AbbrevTree<Label, Contained> node = new AbbrevTree<>(this, key, dat);
+
+		children.put(key, node);
+
+		return node;
+	}
+
+	/**
+	 * Remove a direct child from this node.
+	 * 
+	 * @param key The label for this child.
+	 * 
+	 * @return The removed child.
+	 */
+	public Optional<AbbrevTree<Label, Contained>> removeChild(Label key) {
+		Optional<AbbrevTree<Label, Contained>> res = Optional.ofNullable(children.remove(key));
+
+		res.ifPresent((node) -> {
+			node.parent = null;
+			node.labelledNodes.iterator().forEachRemaining((par) -> {
+				labelledNodes.remove(par.getLeft(), par.getRight());
+
+				parent.labelledNodes.remove(par.getLeft(), par.getRight());
+			});
+		});
+
+		return res;
+	}
+
+	/**
+	 * Retrieve a number of subnodes from this tree which correspond to the given
+	 * keys.
+	 * 
+	 * Note that the keys are passed in reverse order. Essentially, the first
+	 * argument is the actual key, the remainder are just disambiguators
+	 * 
+	 * @param keys The keys to look up.
+	 * 
+	 * @return All of the nodes which match the given key pattern.
+	 */
+	public Set<AbbrevTree<Label, Contained>> nodes(@SuppressWarnings("unchecked") Label... keys) {
+		// Need this; Java can't deduce the proper type for reduceAux otherwise
+		Set<AbbrevTree<Label, Contained>> nodes = new HashSet<>();
+
+		ListEx<Label> keyList = new FunctionalList<>(keys);
+
+		// COBOL keylists are in reverse order
+		keyList.reverse();
+
+		Label last = keyList.popLast();
+
+		List<AbbrevTree<Label, Contained>> focusList = List.of(this);
+		for (Label key : keyList) {
+			List<AbbrevTree<Label, Contained>> nextFocus = new ArrayList<>();
+
+			for (AbbrevTree<Label, Contained> focus : focusList) {
+				Set<AbbrevTree<Label, Contained>> focusSet = focus.labelledNodes.get(key);
+				nextFocus.addAll(focusSet);
+			}
+
+			focusList = nextFocus;
+		}
+
+		focusList.forEach((focus) -> {
+			nodes.addAll(focus.labelledNodes.get(last));
+		});
+
+		if (label.equals(last))
+			nodes.add(this);
+
+		return nodes;
+	}
+
+	/**
+	 * Retrieve all of the values which correspond to a given key.
+	 * 
+	 * 
+	 * Note that the keys are passed in reverse order. Essentially, the first
+	 * argument is the actual key, the remainder are just disambiguators
+	 * 
+	 * @param keys The keys to look up
+	 * 
+	 * @return All of the values which correspond to the key
+	 */
+	public Set<Contained> values(@SuppressWarnings("unchecked") Label... keys) {
+		Set<Contained> res = new HashSet<>();
+
+		nodes(keys).forEach((node) -> res.add(node.data));
+
+		return res;
+	}
+
+	/**
+	 * Returns the singular value identified by the given keypath.
+	 * 
+	 * Note that unlike {@link AbbrevTree#nodes(Object...)} and
+	 * {@link AbbrevTree#values(Object...)}, the keys to this method are passed in
+	 * the proper order, not reverse.
+	 * 
+	 * @param keys The keypath to look up.
+	 * 
+	 * @return An optional containing the identified element if there is one;
+	 *         otherwise, empty.
+	 */
+	public Optional<AbbrevTree<Label, Contained>> path(@SuppressWarnings("unchecked") Label... keys) {
+		Optional<AbbrevTree<Label, Contained>> focus = Optional.of(this);
+
+		for (Label key : keys) {
+			focus.map((node) -> {
+				return node.children.get(key);
+			});
+		}
+
+		return focus;
+	}
+
+	@Override
+	public Iterator<Pair<Label, Contained>> iterator() {
+		return new TransformIterator<>(labelledNodes.iterator(),
+				(node) -> node.mapRight(AbbrevTree<Label, Contained>::getData));
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(children, data, label, parent);
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj)
+			return true;
+		if (obj == null)
+			return false;
+		if (getClass() != obj.getClass())
+			return false;
+		AbbrevTree<?, ?> other = (AbbrevTree<?, ?>) obj;
+		return Objects.equals(children, other.children) && Objects.equals(data, other.data)
+				&& Objects.equals(label, other.label);
+	}
+}
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