scheme vs common lisp

Douglas Thomas Crosher
Sun, 22 Mar 1998 11:01:58 +1000 (EST)

> Hey everyone, I SERIOUSLY suggest you check out RScheme. I reckon
> it is probably THE state of the art Lisp-like language
> implementation out there now.
> For me this now looks like a no-brainer. We should just go and
> use RScheme.

Some of the RScheme features look quite interesting, a few points:

* if you're serious about writing an OS based on either RScheme or
CMUCL you'll probably want to rewrite the thread and garbage
collection implementations anyway to exploit better integration with
the OS.

* having a compiler you can hack on, as for CMUCL, may help in
exploiting a tight coupling between the various subsystems.

* One strong point of CMUCL is the potential of its object
represention scheme to perform well at basic list allocation and
garbage collection. Do you know the memory allocation overhead for a
basic cons object in RScheme, which is 8 bytes in CMUCL?  Just out of
curiosity how does RScheme currently perform on a test of basic list
allocation and garbage collection such as that below which completes
in 16 seconds on CMUCL x86.

Douglas Crosher


(defvar *a* nil)
(defvar *b* nil)

(defun tst ()
  (dotimes (i 20)
    (declare (fixnum i))
    (setf *b* nil)
    (dotimes (j 500000)
      (declare (fixnum j))
      (push (+ i j 1.2345d0) *b*))))