Dr Robert Sanderson wrote:
> On Tue, 1 Mar 2005, Sebastian Hammer wrote:
>
>> At 09:48 PM 3/1/2005 +0000, Dr Robert Sanderson wrote:
>
>
>>>>> * matches zero or more characters.
>>>>> For any field, "*" will match anything, no matter your internal
>>>>> representation of the date.
>
>
>>>> Consider a server that does not support truncation at all. It _will_
>>>> have to do a special case in order to full this "new" requirement. But
>>>> it will reject all other terms with * in it. That's not elegant.
>>>
>>>
>>> As opposed to a relation modifier, which may or may not be supported,
>>> with
>>> special cases for the index, relation and value, which is somehow more
>>> elegant than a not-very-special case for a term only? I beg to differ :)
>
>
>> I think the kind of 'operator overload' which is implied in the use of
>> '*' is an inherently bad idea. Much better to be explicit about what it
>> is we want, and to get 'matches everything' on the table as a clear,
>> pronounced requirement which is visible in the language. Why? Because
>> CQL is already a complex language, and implementors are humans, and
>> humans are likely to make any mistake or take any dumb shortcut you
>> leave open to them in order to reach deadlines. I think buggy
>> implementations of CQL are going to be one of the biggest threats to
>> interoperability (once we get our SOAP toolkits straightened out, or
>> drop SRW :-), and the easier and more clear we can make it, the better.
>
>
> If this were a critical piece of functionality, I would probably agree.
>
> But how many people have implemented the alwaysMatches attribute in
> Z39.50? Anyone? I know that we certainly haven't, and haven't had anyone
> ask us to.
How many have implemented
@attr 5=102 .*
or
@attr 5=3 ""
or
@attr 5=101 #
?
Some servers return zero hits, some never respond in reasonable time,
some fail with "Temporary system error". Some actually respond with the
right number of hits.
I think we should leave things as they are. Let a profile add the
requirement for '*' or special modifier.
Missing regular expressions in CQL ;-)
/ Adam
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