[CWB] CQPWeb -- Negation operator in simple query language

[Stefan Evert]

> Then, may I a suggest to include this negation operator in a future version, if it's not too complex/much work?

Well, that's the "simple" part of the simple query language.  If CEQL could do everything, nobody would learn CQP syntax any more. ;-)

Seriously, I have given some thought to this, of course, but I found that simple negation is rarely needed or very useful unless it's part of a more complex Boolean condition.  Adding such flexible negation patterns to CEQL creates too much complexity for a simple query language -- in my opinion, the more verbose CQP syntax is much better suited to such queries.  And then there's the issue of backward compatibility, as CEQL is by now in use by a fairly large number of BNCweb and CQPweb servers.

What's your concrete use case for the negation?

In any case, CEQL is designed to be extensible, so you can add your own rules (written as Perl subroutines) in order to implement negation (and defined your own syntax that works for your users).  I'm sure that Andrew will allow custom CEQL extension in the CQPweb admin interface sooner or later ...

Best,
Stefan