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Minutes of the 4th Scheme standarization meeting
IEEE/MCS/P1178 Working Group on Scheme
Unapproved Minutes of the Fourth Meeting
January 19, 1990, San Francisco, CA
The meeting was called to order by Christopher Haynes at about 1:45PM.
The attendees were:
Norman Adams Xerox PARC
Scott Burson Blue Space Foundation
William Clinger University of Oregon
Pavel Curtis Xerox PARC
Ken Dickey Tektronix, Inc.
Kent Dybvig Indiana University
Marc Feeley Brandeis University
Dan Friedman Indiana University
Dick Gabriel Stanford University
John Gateley Texas Instruments
Jed Harris Apple Computer
Christopher Haynes Indiana University
Robert Hieb Indiana University
Roger Kirchner Carleton College
William Maddox U. of California at Berkeley
Sidney Marshal Xerox
James Miller Brandeis University
John D. Ramsdell The MITRE Corporation
Benjamin Schreiber Brandeis University
Guy L. Steele, Jr Thinking Machines Inc
1. The agenda was amended; the changes are reflected by the minutes.
2. John D. Ramsdell was elected secretary.
3. Minutes of the third meeting were accepted with no changes.
4. Reports on R4RS, macros, and ISO.
A. Report on R4RS. (Will Clinger)
R4RS is complete except for the appendix describing macros and the
B. Report on the status of the macro committee. (Will Clinger)
1. Syntactic closures are out of favor. Chris Hanson attempted to
implement EXTEND-SYNTAX using syntactic closures. The attempt
was not entirely successful because of a previously unrecognized
technical problem: in some cases an EXTEND-SYNTAX based on
syntactic closures must know the syntactic role of an identifier
before macro expansion has made that role apparent.
2. A proposal based on a descendent of hygienic macro expansion
has some members of the macro committee confident that a
resolution to the macro impasse is at hand. The current
proposal is due to Jonathan Rees, who modified a proposal by
Will Clinger, who based his proposal on Eugene Kohlbecker's
Ph.D thesis work.
C. Report on the International Standards Organization WG-16. (Dick Gabriel)
WG-16 is not currently interested in Scheme as a basis for an
5. Quick review of IEEE standardization procedures. (Chris Haynes)
Resolved: The chair will post instructions to the Scheme notesfiles on
how to request membership in the balloting group for the Scheme standard.
6. Discuss draft P1178/D3.
Many of the agenda items were entered by Sidney Marshall.
A. Consensus: The editors should fix the introduction so that the
definitions of "confirming implementation" and "conforming program"
constrain the implementation to meet the standard.
B. Consensus: No change is needed in the description on pg. 11 of
the "evaluates to" symbol.
C. Consensus: An editorial change shall be made to the section on
disjoint types with "No object satisfies more than one ..."
changed to "Every object satisfies at most one ...".
D. Consensus: The restriction on duplicate entries in CASE key
sets should be removed and the text updated to be consistent
with the derived semantics. That is
(case x ((3.14 3.14159) 'pi) (else '()))
is fine on machines on which (eqv? 3.14 3.14159) => #t, and
key lists are examined inorder to find the first match.
E. Consensus: Add to the text a statement of the form "Assigning
a new value to a variable defined in the initial environment
does not affect the behavior of any procedure defined in the
F. Consensus: Change reference 20 to the second edition of CLtL.
G. Consensus: Change the description of remainder to correctly deal
with the sign of negative zero.
H. Consensus: References to unpublished works should be changed into
references to published works.
Ref 5 --> "The Theory of Numbers," by G H Hardy & E W Wright,
Refs 17 --> William Clinger and Jonathan Rees (editors), The revised^4
report on the algorithmic language Scheme, University of Oregon
Technical Report CIS-TR-90-02.
Ref 22 --> Thinking Machines Technical Report by Guy Steele, Jr.
Section 1.1 should refer to Steele's master's thesis (MIT AI-TR-474)
for a definition of "properly tail recursive".
The bracketed sentence at the end of Appendix C.3 should removed
and the sentence preceding it changed to refer to William Clinger,
How to read floating point numbers accurately, University of
Oregon Technical Report CIS-TR-90-01.
I. Withdrawn: The word "should" should be eliminated from text.
J. Withdrawn: Definitions should be treated syntactically as
K. Moved and rejected: Eliminate CALL-WITH-CURRENT-CONTINUATION
It was argued that elimination would encourage more people to use
IEEE Scheme as their extension language, but others felt Scheme
without CALL-WITH-CURRENT-CONTINUATION is simply not Scheme.
The vote was three for and eleven against.
L. Withdrawn: Change text so that "(BEGIN)" is a legal expression.
M. Moved and rejected: A key set of a CASE form may not be empty.
N. Moved and rejected: Remove named LET from the text.
O. Discussed and rejected: All parts of lists generated by a
quasiquote expression should be mutable.
P. Moved and accepted: Change the text in the section on symbols to
qualify some of the examples with the phrase "symbols as defined
in this report".
Q. Withdrawn: All conforming implementations must support a minimum
6. Moved and unanimously accepted: After amendment to conform with the
consensus of this meeting, and other changes deemed non-controversial
by the editors, draft D3 should be submitted to the MSC for public
comment and balloting.
7. Consensus: An ad hoc subcommittee of this working group will
respond to public comments and negative ballots. The members of
this committee will be Chris Hanson, James S. Miller, and John D.
Ramsdell. Another meeting of the working group will be called
if it is felt that the responses recommended by this subcommittee
may be controversial.
8. Moved and accepted: This working group will terminate its activity when
the draft is accepted as a standard, and will reform when necessary to
revise the standard.
9. Moved and unanimously accepted: The committee thanks Christopher Haynes,
the IEEE editors, David H. Bartley, Chris Hanson, and James S. Miller,
and the RnRS editors, Will Clinger and Jonathan Rees.
10. Moved and accepted: Identify the standard draft editors in the text.
The meeting adjourned at 5:45PM.
-- Minutes by John D. Ramsdell, edited by Christopher Haynes.