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From: db@lfcs.ed.ac.uk (Dave Berry)
Newsgroups: comp.lang.eiffel
Subject: Re: Rename/Redefine Table is Incorrect ?
Message-ID: <2671@castle.ed.ac.uk>
Date: 7 Mar 90 18:26:50 GMT
References: <1190@cf-cm.UUCP>
Reply-To: db@lfcs.ed.ac.uk (Dave Berry)
Organization: Laboratory for the Foundations of Computer Science, Edinburgh U
Lines: 29

In article <1190@cf-cm.UUCP> ted@computing-maths.cardiff.ac.uk (Ted Lawson) writes:
>	One entry in the rename/redefine table on page 155 of
>	Eiffel: The Language (page 260 of OOSC) appears to be incorrect.
>
>	Case 6 of the table claims that
>
>		rename old as new
>		redefine old, new
>
>	causes b.old to bind to the same feature as c.new.

In my recent artticle I assumed that this was the correct semantics.
Howver, I misread Case 4 of the table, for which I apologise.
I thought it read:

	f redefined theta'	theta	theta'	theta
	f renamed f'

The logic being that a1.f would be mapped to b1.f' by the renaming
and that the "redefinition" of f wouldn't affect this.

Now I'm just confused.  Cases 4 and 6 seem to contradict each other.

I apologise if I've confused anyone else.

 Dave Berry, LFCS, Edinburgh Uni.      db%lfcs.ed.ac.uk@nsfnet-relay.ac.uk

"The thought of someone sharing one's own preferences without also sharing
 one's aversions strikes most people as utterly inconceivable." - C. A. Tripp.