;; REPL, SBCL 1.1.7
(defun repl-fun (noprint)
  (/show0 "entering REPL")
  (loop
   (unwind-protect
        (progn
          ;; (See comment preceding the definition of SCRUB-CONTROL-STACK.)
          (scrub-control-stack)
          (sb!thread::get-foreground)
          (unless noprint
            (flush-standard-output-streams)
            (funcall *repl-prompt-fun* *standard-output*)
            ;; (Should *REPL-PROMPT-FUN* be responsible for doing its own
            ;; FORCE-OUTPUT? I can't imagine a valid reason for it not to
            ;; be done here, so leaving it up to *REPL-PROMPT-FUN* seems
            ;; odd. But maybe there *is* a valid reason in some
            ;; circumstances? perhaps some deadlock issue when being driven
            ;; by another process or something...)
            (force-output *standard-output*))
          (let* ((form (funcall *repl-read-form-fun*
                                *standard-input*
                                *standard-output*))
                 (results (multiple-value-list (interactive-eval form))))
            (unless noprint
              (dolist (result results)
                (fresh-line)
                (prin1 result)))))
     ;; If we started stepping in the debugger we want to stop now.
     (disable-stepping))))