Re: type slot option

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: Wed, 4 May 88 18:48 PDT
    From: Gregor.pa@Xerox.COM

    Looking over all the mail, it seems that the best thing to do is to
    leave the :type option the way it is.  

I agree.

	Date: Mon, 02 May 88 08:41:29 -0700
	From: kempf@Sun.COM

	I don't think we should eliminate the :type option, but I think we
	ought to make it work exactly like the defstruct :type option on
	pg. 310 of CLtL. 

I believe that was the intention of the way :type is now, although
the CLtL writeup is sufficiently unclear that it's difficult to be sure.

	Date: 30 Apr 88 10:19 PDT
	From: Dick Gabriel <RPG@SAIL.Stanford.EDU>

	As you all recall, my original writeup of this option stated that
	attempting to store an invalid type SHOULD signal an error. Moon objected
	on the grounds that he did not want to have to ever check it, except when
	other operations would naturally check the contents (such as during an
	addition).

	Thus, I never saw this as a compiler pragma only but as a semantic issue.
	I would favor a redux to my original wording (yes, ``redux'' is the word I
	mean).

I have to object to being painted as an obstructionist.  My position is that
CLOS should be consistent with CL on issues such as this one that are not
specifically related to object-oriented programming.  If X3J13 wants to change
Common Lisp to enforce type declarations always, or in specified circumstances,
that's fine.  In the absence of that I think CLOS should remain consistent
with the imprecision of the rest of Common Lisp.  Otherwise CLOS will
make Common Lisp even more chaotic than it already is.