[comp.lang.eiffel] subtyping/conformance

alastair@comp.lancs.ac.uk (Alastair Macartney) (10/23/89)

Hi people,
		I am currently doing some research into subtyping in object 
oriented languages and would like to know of any systems that employ
automatic (as opposed to user defined) subtyping. I know about the
Comandos, Emerald, and Eiffel and wonder whether there are any more 
systems with different conformance rules.
	In particular I am working on theoretic aspects of subtyping
with and I am trying to see if there is any way that anything apart
from syntactic checking can be used in verifying subtyping. In particular
denotational semantics has come to my attention.

	Any suggestions will be most gratefully received, either via e-mail
to me or by posting to the net.

many thanks in advance

Alastair Macartney
Dept of Computing
Lancaster University
UK
e-mail:	alastair@uk.ac.lancs.comp

jack@cs.glasgow.ac.uk (Jack Campin) (10/27/89)

alastair@dcl-cs.UUCP (Alastair Macartney) wrote:

> I am currently doing some research into subtyping in object 
> oriented languages and would like to know of any systems that employ
> automatic (as opposed to user defined) subtyping.  I know about the
> Comandos, Emerald, and Eiffel and wonder whether there are any more 
> systems with different conformance rules.

Do you mean "structural" by "automatic"?  If so, all of the systems derived
from Cardelli's work do that.  One fairly recent paper I've seen on this
work is Cardelli & Mitchell, "Operations on records", DEC SRC Report 48
(August 1989), DEC Systems Research Center, 130 Lytton Avenue, Palo Alto,
CA 94301.  There is too much stuff going on in this research programme to
summarize here; look in the theoretical computer science journals.

-- 
Jack Campin  *  Computing Science Department, Glasgow University, 17 Lilybank
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