Is there a command to halt the interpreter in Common Lisp?

Question

I\'m looking for an expression that will cause the interpreter to exit when it is evaluated.

I\'ve found lots of implementation-specific ones but none in the HyperSpec,

Answer 1

As far as I know, this is not covered by the Spec, and you will have to use the implementation-specific solutions, or maybe try and look if someone has already written a trivial-quit lib (or start one on CLiki).

If you only care about interactive use, ,q in SLIME will always do the right thing. Otherwise, you may use read-time conditionals like this:

(defun my-quit ()
  #+sbcl (sb-ext:quit)
  #+clisp (ext:exit)
  #+ccl (ccl:quit)
  #+allegro (excl:exit)) ;; and so on ...

#+ checks, if the following symbol is in *features*. If not, the following form will be treated as white-space. (There is also #- for the opposite).