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Top level forms in a compiled file
- To: BENSON @ SPA-NIMBUS
- Subject: Top level forms in a compiled file
- From: Kent M. Pitman <KMP @ MIT-MC>
- Date: Sat, 16 Jul 1983 21:06:00 -0000
- Cc: Common-Lisp @ SU-AI
- In-reply-to: Msg of 14 Jul 1983 18:13-PDT from BENSON at SPA-Nimbus
Date: Thursday, 14 July 1983, 18:13-PDT
From: BENSON at SPA-Nimbus
... This is handled in PSL by having function definitions add a call to FSET
to the list of top level forms to be compiled. It is exactly as if ...
(defmacro defun (name &body body)
`(setf (symbol-function ',name) #',(lambda ,@body)))
Even defining a function twice in a single file and using both
I assume you meant #'(lambda ,@body) rather than #',(lambda ,@body).
In any case, now that you mention it, I once wrote a simple Lisp compiler
which used this same trick. This style of presentation is also satisfactory
to me. It is maximally parallel with scheme, where
(setf (symbol-function ',name) #'(lambda ,@body))
would "macroexpand" to
(setq ,name (lambda ,@body))
In fact, it's probably a loss to have the primitive conceptual unit not be
#'(lambda ...), since anything else is almost sure to eventually turn up
deficient for some extension to def- syntax.
So I'd support this as a semantic model. Actually, named-lambda might be better
than lambda, but that's no big deal.
What follows is just speculation; not in any way a proposal. It's interesting
to note that if
FILE1 = [ (defun f (x) x) (defun g (x) x) ]
(defun g0001 (x) x)
(defun g0002 (x) x)
(defun g0003 () (setf #'f #'g0001) (setf #'g #'g0002))
then (load "FILE1") is the same as (G0003) so we could in principle have a
function PRELOAD which was like LOAD but just "got everything in core" without
doing any major side-effects. Then (LOAD "FILE1") might just do (G0003) without
having to move bits from disk to core. Also, there might be a function RELOAD
which just re-ran G0003 rather than moving a second set of the code into core.
It wouldn't fix bashed constants, but that might either be know to be desirable
or at least harmless for some applications.