URGENT RESPONSE REQUESTED!!!!!

[will@cs.uoregon.edu]

Several voices in the scheme-standard list have begun to urge that
the IEEE standard require #f and the empty list to be distinct.
It is becoming clear that we will never again have the opportunity
to make this change as painlessly as we can today.

I therefore request an extraordinary action: that the R*RS authors
agree, via electronic mail, to pass on the following message to
the IEEE working group on Scheme, P1178:

    We, the R*RS authors, do not object to changing the IEEE draft
    standard to require that #f be distinct from the empty list.
    We are willing to change the R4RS to conform with the IEEE
    standard if this change is made.

I would like to strengthen "do not object to" to "recommend", but
I think "do not object to" is enough for P1178 to consider the matter.
Let me remind you that the IEEE standard cannot become effective
much before the end of this year, and it is far easier to change
an implementation than a standard.

Please respond IMMEDIATELY.  The IEEE draft is about to be submitted
for the balloting process.

Ken Dickey:

    I understand that getting a consensus for disjointness of '() and #f is
    probably not possible at this time and should properly be done in the RNRS
    authors' group.  Not having it done now will certainly come back to haunt
    us.

Jon L White:

    There must certainly be forces of conservatism in the Scheme community
    too.  But unless there is a widespread and nearly unmanageable application
    -- a behemoth of the magnitude of MACSYMA -- or a bevy of commercial
    implementations that will seriously be compromised by remaining firm
    on this issue, then I would strongly encourage the radicals among you
    to "do it right, this time".

Morry Katz:

    ....Since we are currently drafting the first Scheme
    standard, we have the rare opportunity to rectify the traditional mistake of
    allowing '() to act as a boolean.  We should actually mandate the separation of
    these types NOW.  Once the first standard is produced, it will be too late to
    rectify this problem.  Forever after, people will strongly resist an
    incompatible change to the standard.

Guy L Steele Jr:

    This certainly seems to be yet another opportunity to correct
    in Scheme a fundamental mistake in Common Lisp.

Peace, Will