On Thu, 2006-07-27 at 10:02 -0400, Ray Denenberg, Library of Congress
wrote:
>  > I do not believe that this approach was ever discussed; and in any
>  > case it is very much inferior to the simple use of "eq".
> 
> Well first, I think 'eq' is a poor solution, and second,  yes we did have
> discussion -- endless discussion   (on the Ed. Board list) and while it's
> not productive to rehash it, it's worth highlighting a few conclusions:
> 
> -  it is confusing to have both an '=' and 'eq' relation

Which is why we had scr /and/ a semi-magical = that did the right thing.
Now we have one magical =, no scr and eq for equality.

> - but  '=' to replace 'scr' is overwhelming favored, so we need an equality
> relation (to replace the changed '=') -- indeed anchoring was discussed, as
> the way string matching is done for bibliographic data -- but an explicit
> equality relation was also discussed

And is fundamentally necessary. 


> So, neither '=' nor 'eq' is a solution for equality. As I look back on the
> discussion it wasn't clear that 'exact' was to be depricated.

Well, you wrote it in the list of changes for version 1.2, so at some
point it was clear :)

I don't see why 'eq' is not a solution, though.

> I suggest 'exact' for explicit equality. I think it's better than 'eq'.

Why?  

It's an arbitrary token that's defined in a context set, not the
syntax.  

'exact' has existing semantics of string equality.  If we change the
semantics of it to equality of any sort, then we have ambiguity between:

	number exact 1

in the two versions.

Is that a search for 1.0000000 or "1" ?  In 1.1, it's always "1". In 1.2
it would be up to the server to determine (unless there's a relation
modifier specifying the term format).

With =, this is tolerable because you can still do the right thing, and
it was semi-magical anyway. But I don't agree with changing the
semantics of exact, which had well defined semantics of string equality.

What's wrong with eq?

Rob

-- 
Dr Robert Sanderson
Dept of Computer Science, University of Liverpool
Home:     http://www.csc.liv.ac.uk/~azaroth/
Cheshire: http://www.cheshire3.org/