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From: ebm@ibmarc.uucp (Eli Messinger)
Newsgroups: comp.object
Subject: Re: OO Languages with "constraints"
Message-ID: <1164@ks.UUCP>
Date: 26 Oct 89 20:08:58 GMT
References: <89@<GZA> <77500008@m.cs.uiuc.edu>
Sender: news@ibmarc.UUCP
Reply-To: ebm@ibmarc.UUCP (Eli Messinger)
Organization: Pandora's Box
Lines: 38

A good example of integrating a constraint system into an OOL is Alan
Borning's "ThingLab", built on/in Smalltalk-80.  See:

	Borning, Alan, "The Programming Language Aspects of
	ThingLab, A Constraint-Oriented Simulation Laboratory."
	ACM Transactions on Programming Languages and Systems,
	3(4):353-387, October 1981.

	Borning, Alan and Robert Duisberg, "Constraint-Based
	Tools for Building User Interfaces."  ACM Transactions
	on Graphics 5(4), October 1986.

	Borning, Alan, et al. "Constraint Hierarchies."  In
	Proceedings of the 1987 ACM Conference on Object-Oriented
	Programming Systems, Languages and Applications, pp. 48-60,
	October 1987.

	Freeman-Benson, Bjorn, "Constraint Imperative Programming:
	A Research Proposal."  Universit of Washington, Computer
	Science Dept. Technical Report #89-04-06, June 1989.

In article <77500008@m.cs.uiuc.edu> render@m.cs.uiuc.edu writes:
> 
> Written 10:21 pm  Oct 21, 1989 by gza@mentor.cc.purdue.edu:
> >If you always use methods to access instance variables, you can easily
> >implement constrained instance variables in Smalltalk & Objective-C.
> 
> Yeah, but it's nice to make constraints declarative (i.e. height=width)
> and have those things maintained automatically rather than encoding the
> verification procedures by hand.  I think some relational DMBSs provide
> this facility, and it's an interesting idea for OO PLs and DBMSs.


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