Re: Issue: FUNCTION-TYPE (version 4)

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

    Date: 1 Jun 87 16:46 PDT
    From: Gregor.pa@Xerox.COM

    I don't like the current, 'concession to backward compatibility' which
    allows apply, mapcar etc. to accept things which are not functionp.  I
    bet the amount of code which would be affected by this change is small,
    and if we decide to make it now, vendors can make their systems warn
    about it for a while, so the transition should not be too painful.

This kind of warning strategy isn't very effective for things that cannot
be detected at compile time.  A run time warning tends to be a big annoyance
and may not tell you just where in your program was responsible for the
effect.