add optional system message argument to gptel--create-prompt

[neilfulwiler]

not sure if this was a deliberate choice but I assumed it wasn't, I was playing around with gtpel-request and wanted to use the builtin prompt functionality but with a custom system message

[karthink]

Thanks for catching that, I hadn't considered a nil prompt + custom system message.

I'd like to avoid modifying gptel--system-prompt for now, as it needs to be rewritten to support more LLMs soon. Please see the code review for an alternative.

[neilfulwiler]

assuming you mean an upcoming code review, cause I don't see one now (but maybe I don't know how to github). if you haven't gotten around to it yet the other way I could do this is just get the prompt list and pop off the system message and add the custom one back, not sure how stable that data format is though

[karthink]

Not sure why it's not showing up.

Reproduced here:

Instead of modifying gptel--create-prompt, please let-bind gptel--system-message around the call to gptel--create-prompt in gptel-request. Something like this:

          ((null prompt)
           (let ((gptel--system-message
                  (or system gptel--system-message)))
             (gptel--create-prompt start-marker)))

[neilfulwiler]

ah its pending you gotta hit submit, also that makes way more sense than what I said

[karthink]

Cheers @neilfulwiler.