How detach repl from starting terminal/thread?

Question

I am currently working a Lisp project that involves calling a QT GUI through CFFI. We are not using CommonQT but rather built the GUI in C++ and call it through CFFI access to a library we made. When the GUI begins, the goal is to control what happens in it with Lisp calls. Sadly, QT steals the main thread, and the repl window that we started the GUI from is now useless. We get around this by having QT make a Window for us that can accept REPL commands and display REPL results in. It works ok, but it is awkward, and it sure would be nice to be able to keep that original terminal repl. The GUI part works well enough now that I'm trying to split it off into its own thread, and this would be the perfect time to get my terminal back. Any ideas? Some combination of a new thread and some stream redirection?

Answer 1

You might want to try bourdeaux-threads, for example:

(defun start ()
  (bt:make-thread
    #'(lambda ()
        (start-my-repl)))
  (start-qt-app))