community: have ChatLlamaCpp handle "auto" and "any" for tool_choice

libs/community/langchain_community/chat_models/llamacpp.py

@@ -7,6 +7,7 @@
     Dict,
     Iterator,
     List,
+    Literal,
     Mapping,
     Optional,
     Sequence,
@@ -342,15 +343,10 @@ def bind_tools(
         self,
         tools: Sequence[Union[Dict[str, Any], Type[BaseModel], Callable, BaseTool]],
         *,
-        tool_choice: Optional[Union[dict, bool, str]] = None,
+        tool_choice: Optional[Union[dict, bool, str, Literal["auto", "any"]]] = None,
         **kwargs: Any,
     ) -> Runnable[LanguageModelInput, BaseMessage]:
-        """Bind tool-like objects to this chat model
-
-        tool_choice: does not currently support "any", "auto" choices like OpenAI
-            tool-calling API. should be a dict of the form to force this tool
-            {"type": "function", "function": {"name": <<tool_name>>}}.
-        """
+        """Bind tool-like objects to this chat model"""
         formatted_tools = [convert_to_openai_tool(tool) for tool in tools]
         tool_names = [ft["function"]["name"] for ft in formatted_tools]
         if tool_choice:
@@ -363,14 +359,27 @@ def bind_tools(
                         f"provided tools were {tool_names}."
                     )
             elif isinstance(tool_choice, str):
-                chosen = [
-                    f for f in formatted_tools if f["function"]["name"] == tool_choice
-                ]
-                if not chosen:
-                    raise ValueError(
-                        f"Tool choice {tool_choice=} was specified, but the only "
-                        f"provided tools were {tool_names}."
-                    )
+                if tool_choice == "any":
+                    if len(formatted_tools) == 1:
+                        tool_choice = formatted_tools[0]
+                    else:
+                        raise ValueError(
+                            "tool_choice `'any'` only supported if one tool is "
+                            "provided."
+                        )
+                elif tool_choice == "auto":
+                    tool_choice = None
+                else:
+                    chosen = [
+                        f
+                        for f in formatted_tools
+                        if f["function"]["name"] == tool_choice
+                    ]
+                    if not chosen:
+                        raise ValueError(
+                            f"Tool choice {tool_choice=} was specified, but the only "
+                            f"provided tools were {tool_names}."
+                        )
             elif isinstance(tool_choice, bool):
                 if len(formatted_tools) > 1:
                     raise ValueError(
@@ -386,7 +395,6 @@ def bind_tools(
                 )
 
         kwargs["tool_choice"] = tool_choice
-        formatted_tools = [convert_to_openai_tool(tool) for tool in tools]
         return super().bind(tools=formatted_tools, **kwargs)
 
     def with_structured_output(