From 46a9d603f4d1e9ea09d54f3500bcf2f94336b670 Mon Sep 17 00:00:00 2001
From: ksanchez <agent.xaber@gmail.com>
Date: Thu, 2 May 2024 23:29:33 -0600
Subject: [PATCH] Add method to get BOS token.

---
 LLama/LLamaContext.cs                  | 13 ++++++++++++-
 LLama/Native/SafeLLamaContextHandle.cs |  4 +++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/LLama/LLamaContext.cs b/LLama/LLamaContext.cs
index 7d0c0f91..4f8e7d94 100644
--- a/LLama/LLamaContext.cs
+++ b/LLama/LLamaContext.cs
@@ -1,4 +1,4 @@
-using LLama.Exceptions;
+using LLama.Exceptions;
 using LLama.Native;
 using System;
 using System.Collections.Generic;
@@ -521,6 +521,17 @@ namespace LLama
             return candidates_p;
         }
 
+        /// <summary>
+        /// Gets whether or not the Bos token should be added.
+        /// From common.cpp https://github.com/ggerganov/llama.cpp/blob/60325fa56f61c228464c9f065db3aa6a61f2156e/common/common.cpp#L2417
+        /// </summary>
+        /// <returns></returns>
+        public bool ShouldAddBosToken()
+        {
+            var addBos = NativeApi.llama_add_bos_token(NativeHandle.ModelHandle);
+            return addBos != -1 ? Convert.ToBoolean(addBos) : NativeHandle.LLamaVocabType == LLamaVocabType.SentencePiece;
+        }
+
         #region eval overloads
         /// <summary>
         /// </summary>
diff --git a/LLama/Native/SafeLLamaContextHandle.cs b/LLama/Native/SafeLLamaContextHandle.cs
index 51568769..13a7aa1b 100644
--- a/LLama/Native/SafeLLamaContextHandle.cs
+++ b/LLama/Native/SafeLLamaContextHandle.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Runtime.InteropServices;
 using System.Text;
@@ -19,6 +19,8 @@ namespace LLama.Native
         /// </summary>
         public int VocabCount => ThrowIfDisposed().VocabCount;
 
+        public LLamaVocabType LLamaVocabType => ThrowIfDisposed().VocabType;
+
         /// <summary>
         /// Total number of tokens in the context
         /// </summary>