Re: Issue: FUNCTION-TYPE-REST-LIST-ELEMENT

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

    Date: 30 Nov 87 15:29 PST
    From: Masinter.pa@Xerox.COM

    Charniak, Riesbeck, McDermott and Meehan's "Artificial Intelligence Programming", says:

    "Also as recommended in Steele, if &REST is given in a FUNCTION type form, the
    type that follows &REST refers to the type of each argument that &REST collects,
    not to the type of the &REST variable (which is always a list). The definition
    of + might begin

	(DEFUN + (&REST NUMBERS) ...)

     Its type is
	(FUNCTION (&REST NUMBER) NUMBER)."


    Unfortunately, I've never found the place in CLtL where such a recommendation is
    made. 

That's because there isn't one.  Note that the reference was to "Steele", not
to CLtL.  It can be found in document X3J13 / 86-003, a many-times photocopied
5 page document that is apparently entitled "A:>GLS>clarifications.text.4".
A scribble on my copy says "be explicit about &optional, colons; remanded
to declarations committee."  I suppose the declarations committee is one of
those vapor committees that never produces anything?  This seems like a
reasonable thing for the Cleanup committee to address, expanded to cover
all lambda-list keywords in FUNCTION type-specifiers, not just &REST.