improvements and bug fixes

Author: netdur

example/chat.dart

@@ -6,7 +6,8 @@ import 'package:llama_cpp_dart/src/llama_cpp.dart';
 void main() {
   // Initialize settings
   String modelPath = "/Users/adel/Downloads/gemma-3-12b-it-Q4_K_M.gguf";
-  String prompt = "Hello my name is";
+  String prompt =
+      "<start_of_turn>Hello my name is.<end_of_turn>\n<start_of_turn>model\n";
   int ngl = 99;
   int nPredict = 32;
 

example/reasoning.dart

@@ -10,7 +10,8 @@ void main() async {
     String modelPath = "/Users/adel/Downloads/gemma-3-12b-it-Q4_K_M.gguf";
     Llama llama = Llama(modelPath);
 
-    llama.setPrompt("2 * 2 = ?");
+    llama.setPrompt(
+        "<start_of_turn>What is 2 * 4?<end_of_turn>\n<start_of_turn>model\n");
     while (true) {
       var (token, done) = llama.getNext();
       stdout.write(token);

example/rp.dart

@@ -17,6 +17,8 @@ void main() async {
     List<double> embeddings = llama.getEmbeddings("2 * 2 = ?");
     stdout.write(embeddings);
     stdout.write("\n");
+    stdout.write(embeddings.length);
+    stdout.write("\n");
 
     llama.dispose();
   } catch (e) {

example/simple.dart

@@ -1,7 +1,8 @@
 /// Represents supported chat formats for export
 enum ChatFormat {
   chatml,
-  alpaca;
+  alpaca,
+  gemini;
 
   String get value => name;
 }
@@ -80,6 +81,8 @@ class ChatHistory {
         return _exportChatML();
       case ChatFormat.alpaca:
         return _exportAlpaca();
+      case ChatFormat.gemini:
+        return _exportGemini();
     }
   }
 
@@ -119,6 +122,36 @@ class ChatHistory {
     return buffer.toString();
   }
 
+  /// Exports chat history in Gemini format
+  String _exportGemini() {
+    final buffer = StringBuffer();
+
+    for (final message in messages) {
+      switch (message.role) {
+        case Role.user:
+          buffer.write('<start_of_turn>user\n');
+          buffer.write(message.content);
+          buffer.writeln('<end_of_turn>');
+        case Role.assistant:
+          buffer.write('<start_of_turn>model\n');
+          buffer.write(message.content);
+          buffer.writeln('<end_of_turn>');
+        case Role.system:
+          // Gemini doesn't formally support system messages in this format
+          // System messages are typically handled differently or incorporated into user messages
+          // For backward compatibility, we'll include it with a comment
+          buffer.write('<start_of_turn>user\n');
+          buffer.write('System instruction: ${message.content}');
+          buffer.writeln('<end_of_turn>');
+        case Role.unknown:
+          // Skip unknown roles or handle as needed
+          break;
+      }
+    }
+
+    return buffer.toString();
+  }
+
   /// Creates a ChatHistory from JSON
   factory ChatHistory.fromJson(Map<String, dynamic> json) {
     final chatHistory = ChatHistory();