maplist and lists

[Brad Miller <miller@ACORN.CS.ROCHESTER.EDU>]

    Date: Tue, 6 Jan 87 13:01 EST
    From: David C. Plummer <DCP@QUABBIN.SCRC.Symbolics.COM>

	Date: Tue, 6 Jan 87 12:57 EST
	From: Brad Miller <miller@ACORN.CS.ROCHESTER.EDU>


    That's pretty much what I expected.  That still doesn't give an EXACT
    definition.  Consider
	    (maplist #'identity '(1 2 3))
    vs	(maplist #'identity '(1 2 3 . nil))

    One could argue the final "dotted" NIL should be explicitly passed, and
    the result of both would be
	    ((1 2 3) (2 3) (3) NIL)
    instead of the current
	    ((1 2 3) (2 3) (3))

One could argue that, I suppose, but I don't. Since this is not a dotted list
(even if it is input that way it is still a "true" list) the current maplist
would be sufficient, and necessary to maintain compatibility.

Where this is of interest, by the way, consider a pattern matcher:  (A . ?x)
is pretty regular input.  (or ((A B . ?x) D ?y) for that matter...)  the point
is that right now there are no DO or MAP forms that can handle this dotted
form in a trivial way. And, I don't see any particular reason why they
shouldn't. (This may just be shortsightedness on my part...)

Brad Miller
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