Support OpenOrca's prompt format. (& other ChatML local model)

guidance/models/__init__.py

@@ -2,7 +2,7 @@
 
 # local models
 from .transformers._transformers import Transformers, TransformersChat
-from .llama_cpp import LlamaCpp, LlamaCppChat, MistralInstruct, MistralChat
+from .llama_cpp import LlamaCpp, LlamaCppChat, MistralInstruct, MistralChat, MistralChatOpenOrca
 from ._mock import Mock, MockChat
 
 # remote models
@@ -13,4 +13,4 @@
 from ._lite_llm import LiteLLM, LiteLLMChat, LiteLLMInstruct, LiteLLMCompletion
 from ._cohere import Cohere,CohereCompletion, CohereInstruct
 from ._anthropic import Anthropic, AnthropicChat
-from ._googleai import GoogleAI, GoogleAIChat
+from ._googleai import GoogleAI, GoogleAIChat

guidance/models/llama_cpp/__init__.py

@@ -1,2 +1,2 @@
 from ._llama_cpp import LlamaCpp, LlamaCppChat
-from ._mistral import MistralChat, MistralInstruct
+from ._mistral import MistralChat, MistralInstruct , MistralChatOpenOrca

guidance/models/llama_cpp/_mistral.py

@@ -1,5 +1,5 @@
 from .._model import Chat, Instruct
-from ._llama_cpp import LlamaCpp
+from ._llama_cpp import LlamaCpp , LlamaCppChat
 
 class MistralChat(LlamaCpp, Chat):
     def get_role_start(self, role_name, **kwargs):
@@ -27,4 +27,19 @@ def get_role_start(self, role_name, **kwargs):
 
     def get_role_end(self, role_name=None):
         if role_name == "instruction":
-            return " [/INST]"
+            return " [/INST]"
+
+
+class MistralChatOpenOrca(LlamaCppChat, Chat):
+    def get_role_start(self, role_name, **kwargs):
+        if role_name == "user":
+            return "<|im_start|>user\n"
+
+        elif role_name == "assistant":
+            return "<|im_start|>assistant\n"
+
+        elif role_name == "system":
+            return "<|im_start|>system\n"            
+
+    def get_role_end(self, role_name=None):
+        return "<|im_end|>\n"