Feature request: Allow specifying chat history for LMs

[ShaojieJiang]

Hi DSPy developers,

First of all, thanks a lot for this great work!

Recently I've been trying to integrate DSPy into my work, but I stumbled upon the chat history specification. My task is to design a professional interviewer chatbot, therefore, the optimisation target for me is to optimise the conversation flow in diverse cases (such as with both cooperative and uncooperative interviewees). This is different from the existing DSPy modules which mostly focus on answer generation.

Although my task is also roughly answer generation, being able to specify the chat history is important. So I'm wondering is it already planned to add support for history specification? If not, do you think this aligns well with your development agenda?

For the moment I'll add the support in my inherited LM class. Looking forward to your response!

Best regards, Shaojie Jiang