FS:*CANONICAL-TYPES-ALIST*

[John Sterling <sterling%cs.nyu.edu@RELAY.CS.NET>]

Hi,
	We have some lisp files on a Sun that we run under Franz's
Common Lisp.  These files have a ".cl" extension.  I want to run them
from the Symbolics.  I have had no problem previously using DEFSYSTEM
and logical pathnames for files that reside on the Sun, however, in
the past all the files that I was accessing had ".lisp" extensions.
Looking around, I came upon FS:*CANONICAL-TYPES-ALIST*.  This looked
like just the thing.  I did a :

    (push "CL"
	  (cdr (assoc :LISP
		      (cdr (assoc :UNIX42 
				  FS:*CANONICAL-TYPES-ALIST*)))))

And it worked.  At least getting the files with .cl extensions worked.
But now logical pathnames with .lisp extensions translated into
pathnames with .cl extensions (for files on the Sun), resulting in
files previously accessible being no longer found.  Now I'm confused.
I thought that FS:*CANONICAL-TYPES-ALIST* provided a list of
extensions that correspond to a canonical type.  Thus I expected that
any extension would be legitimate to use if it was on that list for
that machine type.

Anyone know the answer?  I can change all my files to have the same
extension if necessary, but I'd like to understand what's going on.

Thanks for your time
John Sterling