Re: MCL 2.0 final defsys package screw

[bill@cambridge.apple.com (Bill St. Clair)]

> Date: Thu, 10 Sep 92 18:09:48 EST
> From: kab@cambridge.apple.com (Kim Barrett)
> To: nathan@akbar.teleos.com
> Subject: Re: MCL 2.0 final defsys package screw
> Cc: info-mcl%cambridge.apple.com@apple.COM
>
> [...]
>
> Another (to me, clearer) way to write it is
>
>  (let ((*package* (if package (find-package package) *package*)))
>    (load path))

This can get you in trouble if FIND-PACKAGE can't find a package
with the given name and returns NIL. Binding *package* to NIL tends
to make MCL very unhappy. Better would be:

(let ((*package* (if package 
                   (or (find-package package)
                       (error "There is no package named: ~s" package))
                   *package*)))
  (load path))