convolute StringMultiTrie generics (to improve theoretical extensibility)

Author: supersaiyansubtlety

enigma/src/main/java/org/quiltmc/enigma/util/multi_trie/CompositeStringMultiTrie.java

@@ -72,7 +72,9 @@ public StringMultiTrie.View<V, Branch<V>, Root<V>> getView() {
 		return this.view;
 	}
 
-	public static final class Root<V> extends StringMultiTrie.Root<V, Branch<V>> {
+	public static final class Root<V>
+			extends MutableMapNode<Character, V, Branch<V>>
+			implements MutableCharacterNode<V, Branch<V>> {
 		private final Collection<V> leaves;
 		private final Map<Character, CompositeStringMultiTrie.Branch<V>> branches;
 
@@ -110,7 +112,9 @@ public CharacterNode<V> getView() {
 		}
 	}
 
-	public static final class Branch<V> extends StringMultiTrie.Branch<V, Branch<V>> {
+	public static final class Branch<V>
+			extends MutableMapNode.Branch<Character, V, Branch<V>>
+			implements MutableCharacterNode<V, Branch<V>> {
 		private final MutableMapNode<Character, V, CompositeStringMultiTrie.Branch<V>> parent;
 		private final Character key;
 
@@ -192,9 +196,9 @@ protected CompositeStringMultiTrie<V> getViewed() {
 	}
 
 	private static final class NodeView<V> extends Node.View<Character, V> implements CharacterNode<V> {
-		private final MutableCharacterNode<V, Branch<V>> viewed;
+		final MutableCharacterNode<V, Branch<V>> viewed;
 
-		private NodeView(MutableCharacterNode<V, Branch<V>> viewed) {
+		NodeView(MutableCharacterNode<V, Branch<V>> viewed) {
 			this.viewed = viewed;
 		}
 

enigma/src/main/java/org/quiltmc/enigma/util/multi_trie/StringMultiTrie.java

@@ -1,8 +1,7 @@
 package org.quiltmc.enigma.util.multi_trie;
 
 import org.quiltmc.enigma.util.Utils;
-import org.quiltmc.enigma.util.multi_trie.StringMultiTrie.Branch;
-import org.quiltmc.enigma.util.multi_trie.StringMultiTrie.Root;
+import org.quiltmc.enigma.util.multi_trie.StringMultiTrie.MutableCharacterNode;
 
 import java.util.Optional;
 import java.util.function.BiFunction;
@@ -26,7 +25,12 @@
  * @param <V> the type of values
  * @param <B> the type of branch nodes
  */
-public abstract class StringMultiTrie<V, B extends Branch<V, B>, R extends Root<V, B>>
+public abstract class StringMultiTrie
+		<
+			V,
+			B extends MutableMapNode.Branch<Character, V, B> & MutableCharacterNode<V, B>,
+			R extends MutableMapNode<Character, V, B> & MutableCharacterNode<V, B>
+		>
 		implements MutableMultiTrie<Character, V> {
 	protected static Optional<Character> tryToggleCase(char c) {
 		if (Character.isUpperCase(c)) {
@@ -154,15 +158,12 @@ default MutableCharacterNode<V, B> nextIgnoreCase(Character key) {
 		}
 	}
 
-	public abstract static class Root<V, B extends Branch<V, B>>
-			extends MutableMapNode<Character, V, B>
-			implements MutableCharacterNode<V, B> { }
-
-	public abstract static class Branch<V, B extends Branch<V, B>>
-			extends MutableMapNode.Branch<Character, V, B>
-			implements MutableCharacterNode<V, B> { }
-
-	public abstract static class View<V, B extends Branch<V, B>, R extends Root<V, B>>
+	public abstract static class View
+			<
+				V,
+				B extends MutableMapNode.Branch<Character, V, B> & MutableCharacterNode<V, B>,
+				R extends MutableMapNode<Character, V, B> & MutableCharacterNode<V, B>
+			>
 			implements MultiTrie<Character, V> {
 		@Override
 		public CharacterNode<V> getRoot() {