Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!decvax!genrad!mit-eddie!mit-vax!eagle!mhuxt!mhuxi!mhuxa!houxm!hocda!spanky!burl!duke!unc!tim
From: tim@unc.UUCP
Newsgroups: net.lang.lisp
Subject: Re: Franz flavors?
Message-ID: <5543@unc.UUCP>
Date: Tue, 12-Jul-83 11:27:08 EDT
Article-I.D.: unc.5543
Posted: Tue Jul 12 11:27:08 1983
Date-Received: Wed, 13-Jul-83 08:19:36 EDT
References: gatech.288
Lines: 36


    Someone asked for a review of the "flavor" idea in Lisp and for a
source for Franz Flavors.

    There are two different and (from what I hear) incompatible
implementations of flavors for Franz.  One was done at MIT, and is not
yet publicly available, according to discussion on the FRANZ-FRIENDS
mailing list.  The other was done at the University of Maryland; you
can get information by writing Liz Allen (umcp-cs!liz).

    Flavors are very useful in large systems design.  It is natural to
conceive of a large system in terms of objects and messages between
them.  Flavors allow you to translate such a design into code very
simply.  Each system component is the sole instance of its own flavor
in this sort of design.

    The benefits of abstract data types are well-known, so I won't go
into them here.  Flavors provide a flexible and comprehensible
abstract data type mechanism, regardless of the system design
applications.

    A bad thing is that flavors in the UoM Franz Flavors
implementation do provide a non-negligible overhead.  Sending a
message to an instance of a flavor is slower than calling a function.
Reportedly, people at UoM are working on a 10%-15% speedup of message
passing, but even with that the overhead will be significant in Franz.
(Please do NOT write me or anyone else asking about this speedup.  It
will be announced when it is ready, and your questions will not
accelerate its progress; rather the opposite, in fact.)

______________________________________
The overworked keyboard of Tim Maroney

duke!unc!tim (USENET)
tim.unc@udel-relay (ARPA)
The University of North Carolina at Chapel Hill