[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: bug in assoc

Common Lisp also faces the possibility of inconsistent system code due
to the handling of cases marked "is an error" (see Manual, sec. 1.2.4);
that is, it is undefined as to what happens if you apply CAR to a
non-LISTP.  All portable system code should therefore certify the type
of a datum before taking car or cdr.  ASSOC (and ASSQ) from the Franz
sources clearly doesn't check the type of the arguments before carcdring
away on them.

Well, why not "all system code should certify the type before taking
car/cdr . . . " -- it certainly can't hurt to "signal an error" rather
than fall into some undefined morass.

-- JonL --