Which constants must be quoted?

[CPH%OZ.AI.MIT.EDU@XX.LCS.MIT.EDU]

    Date: Thursday, 13 February 1986  15:58-EST
    From: Jonathan A Rees <JAR at MC.LCS.MIT.EDU>

    So I think that an intermediate position between 2 and 3 *can* be
    justified by the principle of Occam's razor, and we should disallow
    self-evaluation of vectors, procedures, and other "random" objects
    because it's unnecessary.  That is, the class of legitimate programs
    should be as small as is reasonable.

    I disagree with Chris's statement that it is "Lisp tradition" for random
    objects to self-evaluate.

I agree with you about this -- I wasn't thinking about objects like
procedures and such.  In fact, when I wrote that I had in mind only
objects for which there is read syntax, specifically: lists, symbols,
vectors, strings, characters, numbers, and booleans.  I believe that
tradition does conform to my statement with this restriction.  All of
the other things should cause errors, as you seem to suggest.

I don't care whether vectors are self-evaluating, but I think that
strings and numbers should be.  As for characters and booleans: I
prefer that they self-evaluate, because I use them often and there
seems no very good reason to require that they be quoted.