Re: Issue: TAILP-NIL (Version 4)

[Kent M Pitman <KMP@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: Fri, 2 Dec 88 00:01 EST
    From: "Steve Bacher (Batchman)" <SEB1525@draper.com>

    re: test case #5:
	(TAILP 3 '(A B C . 3))
	returns T under this proposal.
  
    Not necessarily.  It must be kept in mind that numbers are not necessarily EQ.
    I know you believe that all implementations have immediate fixnums, but this
    isn't the case with ours (tho it hurts to admit it).

Good point. Clearly the bug is that we say EQ and not EQL in the
description.  Hardly anything defaults to EQ tests, after all. This
would be irregular if we let it through using EQL.

Someone's going to tell me that this slows it down again. [It needn't
slow it much, of course, though for inlined code you'd get a little code
bloating because you'd have to jumpt to one of two loops. For TAILP
notinline, it would be little overhead to have the two loops. I don't
know how many implementations inline this, though -- certainly ours
doesn't]

Does anyone think that making it use EQL rather than EQ is going to be
prohibitive?