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From: fjh@mundook.cs.mu.OZ.AU (Fergus Henderson)
Subject: Re: Uninitialized "out" parameters
Date: 1996/07/21
Message-ID: <4ssn9r$p6e@mulga.cs.mu.OZ.AU>#1/1
X-Deja-AN: 169295046
references: <4smh9i$gp5@krusty.irvine.com> <4smmhe$9cs@goanna.cs.rmit.edu.au>
 <4smo24$h25@krusty.irvine.com> <31EF9DFC.6FB4@csehp3.mdc.com>
 <4ss763$2aq@felix.seas.gwu.edu>
organization: Comp Sci, University of Melbourne
newsgroups: comp.lang.ada
Date: 1996-07-21T00:00:00+00:00
List-Id: <comp.lang.ada>


mfeldman@seas.gwu.edu (Michael Feldman) writes:

>It _cannot_ be a compiler error, because in general it is undecidable
>whether a variable is used before it is initialized.

Sure it could be a compiler error.  I know of at least one language
for which that is the case, and there are probably others.
(I'm not sure, but Java may be one of them?)

Note that type correctness (defined in the dynamic sense) is also
undecidable -- yet there are certainly *lots* of languages for which
the compiler enforces type safety at compile time.

--
Fergus Henderson <fjh@cs.mu.oz.au>   |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
PGP: finger fjh@128.250.37.3         |     -- the last words of T. S. Garp.