From 7738a4028c167154c0c41da5281bbb566eee0e5b Mon Sep 17 00:00:00 2001
From: Harald Wolff <haraldwolff@pc-harald.waldrennach.l--n.de>
Date: Thu, 1 Apr 2021 15:45:02 +0200
Subject: [PATCH] Added BTree.TryGetNextOrCurrent(),
 BTree.TryGetNextOrCurrentValue()

---
 ln.collections/BTree.cs | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/ln.collections/BTree.cs b/ln.collections/BTree.cs
index 0f5c2ba..ae613f2 100644
--- a/ln.collections/BTree.cs
+++ b/ln.collections/BTree.cs
@@ -303,6 +303,43 @@ namespace ln.collections
             return true;
         }
 
+        public bool TryGetNextOrCurrent(K current, out K nextOrCurrent)
+        {
+            if (Empty)
+            {
+                nextOrCurrent = default(K);
+                return false;
+            }
+
+            TreeNode next = FindFirstGE(current);
+            if (next == null)
+            {
+                nextOrCurrent = default(K);
+                return false;
+            }
+            
+            nextOrCurrent = next.Key;
+            return true;
+        }
+        public bool TryGetNextOrCurrentValue(K current, out V nextOrCurrentValue)
+        {
+            if (Empty)
+            {
+                nextOrCurrentValue = default(V);
+                return false;
+            }
+
+            TreeNode next = FindFirstGE(current);
+            if (next == null)
+            {
+                nextOrCurrentValue = default(V);
+                return false;
+            }
+            
+            nextOrCurrentValue = next.Value;
+            return true;
+        }
+
 
 
         private TreeNode First(TreeNode node)