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From: rentsch@unc.UUCP
Newsgroups: comp.lang.misc
Subject: Re: Dynamically bound and statically typed (was: OOPS)
Message-ID: <989@unc.unc.UUCP>
Date: Mon, 23-Feb-87 02:57:50 EST
Article-I.D.: unc.989
Posted: Mon Feb 23 02:57:50 1987
Date-Received: Thu, 26-Feb-87 19:14:00 EST
References: <4337@columbia.UUCP> <4000007@nucsrl.UUCP>
Reply-To: rentsch@unc.UUCP (Tim Rentsch)
Organization: CS Dept, U. of N. Carolina, Chapel Hill
Lines: 30
Summary: Pointer to 1982 POPL paper by Borning and Ingalls

In article <4000007@nucsrl.UUCP> gore@nucsrl.UUCP (Jacob Gore) writes:
> / rentsch@unc.UUCP (Tim Rentsch) /  3:33 am  Feb 15, 1987 /
> > [...]  by adding "type" declarations to a Smalltalk program, it
> > is possible for the compiler to check "types" at compile time, and
> > guarantee that 'message not understood' errors will not occur at
> > runtime.  [...]
> > 
> > On the other hand:  even in the situation described in the paragraph
> > above, it is not possible to know which method body will be bound to
> > a given message (indeed more than one method body may be bound, at
> > different times, to any particular message send).  Even though we
> > know at compile time that 'message not understood' errors cannot
> > occur -- in other words the code is statically checked -- we do not
> > know (cannot know) which methods will be bound to which message sends.

> Could you give an example?  Just invent a typing syntax for Smalltalk, and
> demonstrate on some short program sections.

I know this will sound like a lame excuse -- but could I refer you to
the 1982 POPL paper on the subject, (by Alan Borning and Dan
Ingalls)?  This paper has all the dope, examples included, and notes
from the implementation.

If you have more questions (or if you can't find the paper), let me
know and I will post an example.  [Sorry I'm too burned out to post
one right away.]

cheers,

Tim