chat_history() when the input is a data.frameCreates a chat_history object from a data frame.
# S3 method for data.frame
chat_history(chat_history)A valid chat history data.frame (of class chat_history),
with the 'role' and 'content' columns as specified in the input data frame
A data frame with 'role' and 'content' columns, where 'role' is either 'user', 'assistant', or 'system', and 'content' is a character string representing a chat message