From 4a96d9cad446ea405b51dfeebb01a1b6d7f6fb2b Mon Sep 17 00:00:00 2001
From: Ben Culkin <scorpress@gmail.com>
Date: Tue, 27 Sep 2022 19:21:16 -0400
Subject: Add some interesting new things

Adds a number of things based off of some of the notes I've made over
time, plus a few papers I've read.

More details to come later, whenever I decide to actually get serious
about documentation and examples and the like
---
 base/src/main/java/bjc/utils/graph/AlgGraph.java | 88 ++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 base/src/main/java/bjc/utils/graph/AlgGraph.java

(limited to 'base/src/main/java/bjc/utils/graph/AlgGraph.java')

diff --git a/base/src/main/java/bjc/utils/graph/AlgGraph.java b/base/src/main/java/bjc/utils/graph/AlgGraph.java
new file mode 100644
index 0000000..7c9d38d
--- /dev/null
+++ b/base/src/main/java/bjc/utils/graph/AlgGraph.java
@@ -0,0 +1,88 @@
+package bjc.utils.graph;
+
+import bjc.functypes.Container;
+
+/**
+ * A directed algebraic graph
+ * 
+ * (ref. Algebraic Graphs with Class, Andrey Mokhov}
+ * 
+ * @author bjcul
+ *
+ * @param <Vertex> The type of the vertexes
+ * @param <PGraph> Containing type parameter
+ */
+public interface AlgGraph<Vertex, PGraph extends AlgGraph<?, PGraph>> extends Container<Vertex, AlgGraph<?, PGraph>> {
+	/**
+	 * Create a empty algebraic graph.
+	 * 
+	 * @param <B> The type of the vertices
+	 * 
+	 * @return A new empty graph.
+	 */
+	<B> AlgGraph<B, PGraph> empty();
+	
+	/**
+	 * Create a algebraic graph with a single vertex
+	 * 
+	 * @param val The value for the vertex
+	 * 
+	 * @return A new graph with the given vertex
+	 */
+	<B> AlgGraph<B, PGraph> vertex(B val);
+	
+	/**
+	 * Overlay a graph onto this one, adding its vertices and edges.
+	 * 
+	 * @param other The graph to overlay
+	 */
+	void overlay(AlgGraph<Vertex, PGraph> other);
+
+	/**
+	 * Connect a graph to this one, adding its vertices and edges; as well as
+	 * establishing an edge from each node in this graph, to each node in the other
+	 * graph.
+	 * 
+	 * @param other The graph to connect
+	 */
+	void connect(AlgGraph<Vertex, PGraph> other);
+	
+	/**
+	 * Overlay two graphs into a new graph.
+	 * 
+	 * @param <Vertex> The type of the vertices.
+	 * 
+	 * @param left     The graph to overlay onto
+	 * @param right    The graph being overlaid
+	 * 
+	 * @return The overlaid graph.
+	 */
+	public static <Vertex, G extends AlgGraph<Vertex, G>> G overlay(G left, G right) {
+		@SuppressWarnings("unchecked")
+		// We know this cast is good, java just can't tell
+		G result = (G) left.empty();
+		result.overlay(left);
+		result.overlay(right);
+
+		return result;
+	}
+
+	/**
+	 * Connect two graphs into a new graph.
+	 * 
+	 * @param <Vertex> The type of the vertices.
+	 * 
+	 * @param left     The graph to connect to
+	 * @param right    The graph being connected
+	 * 
+	 * @return The connected graph.
+	 */
+	public static <Vertex, G extends AlgGraph<Vertex, G>> G connect(G left, G right) {
+		@SuppressWarnings("unchecked")
+		// We know this cast is good, java just can't tell
+		G result = (G) left.empty();
+		result.overlay(left);
+		result.connect(right);
+		return result;
+	}
+}
\ No newline at end of file
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