Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!boulder!gore!jacob
From: jacob@gore.com (Jacob Gore)
Newsgroups: comp.lang.eiffel
Subject: Re: Modification of previous enhancement ideas
Message-ID: <120014@gore.com>
Date: 15 Feb 90 08:08:30 GMT
References: <48a48a6e.12c9a@digital.sps.mot.com>
Reply-To: jacob@gore.com (Jacob Gore)
Organization: Gore Enterprises
Lines: 30

/ comp.lang.eiffel / shelley@atc.sps.mot.com (Norman K. Shelley) / Feb 14 1990/
> 4.) Assertion labels can be misleading and if an assertion is modified
> the label should be probably be modified also. The label is redundant in
> many cases and the assertion is all one might need to see

Do people use labels for comments?  For example, consider the assertion

	x /= 0;

Now I want to document it, to explain why that assertion is made:

	x /= 0; -- since it could be a divisor

Oops!  That's safe enough as far as execution is concerned, but the
semantics of assertions say that a comment is an assertion by itself (an
informal assertion).  So the above should be read as two assertions,
rather than a single documented one.

But one can document an assertion with a tag:

	x_could_be_a_divisor_so_it_must_be_nonzero: x /= 0;

(yeah, I know, it is a silly identifier).

I have not done any real programming in Eiffel, so I'd like to know how
people who have feel about this.

Jacob
--
Jacob Gore		Jacob@Gore.Com			boulder!gore!jacob