Add a standard key strategy for maps without prefixe

Remove the stupid "next" field

PersistentMap/KeyStrategies.cs

@@ -21,6 +21,37 @@ public interface IKeyStrategy<K>
 }
 
 
+/// <summary>
+/// A universal key strategy for any type that relies on standard comparisons 
+/// (IComparable, IComparer, or custom StringComparers) without SIMD prefixes.
+/// </summary>
+public readonly struct StandardStrategy<K> : IKeyStrategy<K>
+{
+    private readonly IComparer<K> _comparer;
+
+    // If no comparer is provided, it defaults to Comparer<K>.Default
+    // which automatically uses IComparable<K> if the type implements it.
+    public StandardStrategy(IComparer<K>? comparer = null)
+    {
+        _comparer = comparer ?? Comparer<K>.Default;
+    }
+
+    // Tell the B-Tree to skip SIMD routing and just use LinearSearch
+    public bool UsesPrefixes => false;
+
+    // This will never be called because UsesPrefixes is false, 
+    // but we must satisfy the interface.
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public long GetPrefix(K key) => 0;
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public int Compare(K x, K y)
+    {
+        return _comparer.Compare(x, y);
+    }
+}
+
+
 public struct UnicodeStrategy : IKeyStrategy<string>
 {
     [MethodImpl(MethodImplOptions.AggressiveInlining)]

PersistentMap/Nodes.cs

@@ -91,7 +91,6 @@ public sealed class LeafNode<K, V> : Node<K>
     
     public K[]? Keys;
     public V[] Values;
-    public LeafNode<K, V>? Next;
 
     internal long[]? _prefixes;
     
@@ -111,9 +110,7 @@ public sealed class LeafNode<K, V> : Node<K>
     {
         Keys = new K[Capacity];
         Values = new V[Capacity];
-        Header.Count = original.Header.Count;
+        Header.Count = original.Header.Count;        _prefixes = new long[Capacity];
-        Next = original.Next;
-        _prefixes = new long[Capacity];
 
         // Copy data
         Array.Copy(original.Keys, Keys, original.Header.Count);

PersistentMap/Readme.org

@@ -1,4 +1,4 @@
-* NiceBtree (PersistentMap)
+* PersistentMap
 
 A high-performance, persistent (Copy-on-Write) B+ Tree implemented in C#. 
 
@@ -14,6 +14,8 @@ It is designed for zero-overhead reads, SIMD-accelerated key routing, and alloca
 ** When should I use this? 
 Never, probably. This was just a fun little project. If you want a really fast immutable sorted map you should consider it. Despite this map being faster than LanguageExt.HashMap for some key types, you should definitely use that if you don't need a sorted collection. It is well tested and does not have any problems key collisions, which will slow this map down by a lot.
 
+The general version of this, using =StandardStrategy<K>= does not benefit from the prefix optimization.
+
 ** Quick Start
 
 *** 1. Basic Immutable Usage