(declare (type fixnum ---)) considered etc.

[David C. Plummer <DCP@QUABBIN.SCRC.Symbolics.COM>]

    Date: Mon, 21 Jul 1986  20:45 EDT
    From: "Scott E. Fahlman" <Fahlman@C.CS.CMU.EDU>


    We certainly can't remove the fixnum declaration, 

Sorry, I don't see this as given.  We can have a type of FIXNUM for
those that wanted to look, but we can make it illegal as a type
declaration because it produces non-portable code.  I think a type
declaration of (signed-byte 32) is CORRECT for what the programmer meant
and therefore much more appropriate.

    but we can warn against this problem in the new spec.  Whether
    anyone heeds the warning is another matter.

Languages should be useful and helpful for programmers (whether those
programmers are human or otherwise).  Warnings should be heeded.  One
could try arguing that if a function compiles with a warning, then the
compiler is at liberty to redefine the function as if it were written
	(defun foo (&rest ignore)
	  (declare (ignore ignore))
	  (break))
and force the user to write code that at least passes the compiler's
tests.