Emacs Lisp: How to, an interactive buffer with REPL?

Question

Imagine the dunnet.el game, the eliza doctor or the IELM mode...; This is, evaluating answers and prompting new questions on the main buffer, then making some actions according to their elisp rules.

I would to create something like an interactive assistant, BUT NOT prompting from minibuffer as (interactive) does (not doing M-x)... I need a kind of REPL loop. So the question i how to get interaction on the working buffer (the main screen), like any text conversational/adventure, but for call my defun'ed functions on this way.

So i need a basic elisp skeleton, to make a custom REPL. The target is to make an assistant with a natural language, then parsing the anwsers, and making some actions according the rules.

Thank you for your time,

Steve,

Answer 1

Check out ielm, which is an elisp repl included with emacs.

Answer 2

Depending on what can go on in your buffer, can you just give it a major mode with an appropriate re-binding of return? (This answer vaguely inspired by Lisp-Interaction-Mode's C-j)