As of Nov 6, 2023, OpenAI added the ability for a single assistant message to request calling multiple functions in
parallel, and wrapped all function calls in a `ToolCall` wrapper. In order to add support for this in kani while
maintaining backwards compatibility with OSS function calling models, a `ChatMessage` now actually maintains the
following internal representation:
`ChatMessage.function_call` is actually an alias for `ChatMessage.tool_calls[0].function`. If there is more
than one tool call in the message, when trying to access this property, kani will raise an exception.
To translate kani's FUNCTION message types to OpenAI's TOOL message types, the OpenAIEngine now performs a translation based on binding free tool call IDs to following FUNCTION messages deterministically.
Breaking Changes
To the kani end user, there should be no change to how functions are defined and called. One breaking change was necessary:
- `Kani.do_function_call` and `Kani.handle_function_call_exception` now take an additional `tool_call_id` parameter, which may break overriding functions. The documentation has been updated to encourage overriders to handle `*args, **kwargs` to prevent this happening again.
New Features
kani can now handle making multiple function calls in parallel if the model requests it. Rather than returning an ASSISTANT message with a single `function_call`, an engine can now return a list of `tool_calls`. kani will resolve these tool calls in parallel using asyncio, and add their results to the chat history in the order of the list provided.
Returning a single `function_call` will continue to work for backwards compatibility.